Fixed tcoin code1 and tcoin code2 leak, and refactored file permissions into a preprocessor macro

Fixed issue with tcoin code1 and tcoin code2. Now they're sent via stdin instead of as arguments to tcoin.

Refactored file permissions into a preprocessor macro.

1 files changed, 2294 insertions, 0 deletions

diff --git a/pcoin.cpp b/pcoin.cpp
index 242dc21..92d7eec 100644
--- a/pcoin.cpp
+++ b/pcoin.cpp
@@ -0,0 +1,2294 @@
+#include <iostream>
+#include <fstream>
+#include <cstdlib>
+#include <cstdio>
+#include <sstream>
+#include <cstring>
+#include <memory>
+#include <stdexcept>
+#include <array>
+#include <vector>
+#include <string>
+#include <algorithm>
+#include <iterator>
+#include <sys/stat.h>
+#include <ctime>
+#include <unistd.h>
+#include "popen2.h"
+//set to 1 to enable some debug std::cout statements
+#define DEBUG 0
+
+#include "pcoin_defs.cpp"
+
+/* OLD VALUES */
+/*
+#define TCOIN_PATH "/home/login/tcoin"
+#define TCOIN_MSG_PATH "/home/login/tcoin/messages/"
+#define TCOIN_SALT_PATH "/home/login/tcoin/salts/"
+#define TCOIN_PASS_PATH "/home/login/tcoin/passwords/"
+#define TCOIN_PROG_ACT_PATH "/home/login/tcoin/program_accounting/"
+#define PROG_ACT_W_SLASH "program_accounting/"
+#define PCOIN_KEY_PATH_W_SLASH "/home/login/bin/pcoin_keys/"
+#define PCOIN_NEW_KEY_CMD "/bin/cat /dev/urandom | /usr/bin/base64 | /usr/bin/head -c 64 | /usr/bin/tr '+' '-' | /usr/bin/tr '/' '_'"
+#define LS_PCOIN_KEY_CMD "/bin/ls /home/login/bin/pcoin_keys"
+#define TCOIN_CODEZ_PATH "/home/login/bin/tcoin_codez"
+#define TCOIN_BIN_PATH_W_SPACE "/home/login/bin/tcoin "
+
+#define PCOIN_BIN_PATH "/home/login/bin/pcoin"
+#define PCOIN_BIN_PATH_W_SPACE "/home/login/bin/pcoin "
+#define TCOIN_PATH_W_SLASH "/home/login/tcoin/"
+#define TCOIN_SCRYPT_PATH "/home/login/bin/scrypt"
+*/
+
+#define LS_HOME_CMD "/bin/ls /home"
+#define BIN_ECHO_CMD "/bin/echo $$"
+#define CHMOD_PERMISSIONS ((S_IRUSR | S_IWUSR) & ~S_IRWXG & ~S_IRWXO)
+#define CHMOD_PROGRAM_KEY_PERMISSIONS (S_IRUSR & ~S_IWUSR & ~S_IXUSR & ~S_IRWXG & ~S_IRWXO)
+#ifndef KROWBAR_OFF
+  #define KROWBAR_SCORE_PATH "/home/krowbar/Code/irc/data/tildescores.txt"
+  #define JU_SCORE_PATH "/home/jmjl/dev/juju/data/tildescores.txt"
+#endif
+#ifndef DA_OFF
+  #define TROIDO_DACOINS_CMD "cd /home/troido/daily_adventure/client/ && /home/troido/daily_adventure/client/daclient printinfo 2>&1 | /bin/grep -oP '(?<=\"Coins\", )\[[:digit:]]+'"
+#endif
+#ifndef MINERCOIN_OFF
+  #define MINERCOIN_CMD_PRE_USERNAME "/bin/grep -oP '(?<=\"~"
+  #define MINERCOIN_CMD_PRE_USERNAME2 "/bin/grep -oP '(?<=\""
+  #define MINERCOIN_CMD_POST_USERNAME "\": )[[:digit:]]+' /home/minerobber/Code/minerbot/minercoin.json"
+#endif
+#define USERNAME_LENGTH_LIMIT 25
+#define TCOIN_MSG_LENGTH_LIMIT 280
+
+#define ERR_MAIN_SEND_TOO_FEW_ARGS 6
+#define ERR_MAIN_SEND_TOO_MANY_ARGS 7
+#define ERR_MAIN_SEND_TOO_MANY_ARGS_MSG 104
+#define ERR_SILENTSEND 2
+#define ERR_MAIN_MSG_TOO_LONG 19
+#define ERR_UNKNOWN_ARG 3
+#define ERR_TCOIN_TO_SELF 5
+#define ERR_RECEIVER_BLOCKED 4
+#define ERR_NEGATIVE_SEND_AMOUNT 2
+#define ERR_INSUFFICIENT_FUNDS 3
+#define ERR_RECEIVER_NOT_FOUND 1
+
+#define ERR_PCOIN_KEY_REFRESH_FAILED 20
+
+#define ERR_IN_GET_INTERNAL_BALANCE -1
+#define ERR_IN_ADD_INTERNAL_BALANCE_GET_INTERNAL_TOTAL_OWED_FAILED -3
+#define ERR_ADD_INTERNAL_BALANCE_VALUE_TO_ADD_UNFULFILLABLE_USING_OWN_CURRENT_FUNDS -1
+#define ERR_ADD_INTERNAL_BALANCE_USERNAME_DOESNT_EXIST -2
+#define ERR_ADD_INTERNAL_BALANCE_ADD_TO_SELF -4
+#define ERR_ADD_FILE_VALUE_INSUFFICIENT_FUNDS 1
+#define ERR_ADD_FILE_VALUE_FATAL 999
+#define ERR_IN_GET_INTERNAL_TOTAL_OWED_SELF_PROGRAM_DOESNT_EXIST -1
+#define ERR_GET_FILE_VALUE_COULDNT_OPEN_BASEFILE 1
+#define ERR_ADD_FILE_VALUE_COULDNT_OPEN_BASEFILE 1
+#define ERR_SEND_MESSAGE_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL 101
+#define ERR_SEND_MESSAGE_PROGRAM_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL 103
+#define ERR_SEND_MESSAGE_SENDER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL 102
+#define ERR_SEND_MESSAGE_SENDER_PROGRAM_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL 104
+
+#define ERR_KEY_EMPTY 22
+#define ERR_KEY_NOT_IN_USE 9
+#define ERR_NO_ARGS 8
+#define ERR_IN_MAIN_GET_INTERNAL_TOTAL_OWED_FAILED 18
+#define ERR_INTERNAL_BALANCE_USERNAME_NOT_FOUND 17
+#define ERR_INTERNAL_BALANCE_NO_USERNAME_SUPPLIED 10
+#define ERR_INTERNAL_BALANCE_TOO_MANY_ARGS 11
+#define ERR_ADD_INTERNAL_BALANCE_TOO_FEW_ARGS 12
+#define ERR_ADD_INTERNAL_BALANCE_TOO_MANY_ARGS 13
+#define ERR_IN_MAIN_ADD_INTERNAL_BALANCE_AMOUNT_LARGER_THAN_COVERABLE_BY_UNOWED_BALANCE 14
+#define ERR_IN_MAIN_ADD_INTERNAL_BALANCE_AMOUNT_MAKING_USER_INTERNAL_BALANCE_NEGATIVE 16
+#define ERR_IN_MAIN_ADD_INTERNAL_BALANCE_NO_SUCH_USERNAME_FOUND 15
+#define ERR_IN_MAIN_ADD_INTERNAL_BALANCE_ADD_TO_SELF 21
+
+void exit_program(const int error_number)
+{
+  // Cleanup to do before exiting the program
+
+  // Finally, we can exit
+  std::exit(error_number);
+}
+
+//custom function to convert ("abcd.de") to ("abcde")
+long long int strtol100(const char* amount_str)
+{
+  long long int result = 0;
+  int multiplier = 1;
+  int i=0;
+  if(amount_str[i]=='-')
+  {
+    multiplier = -1;
+    ++i;
+  }
+  else if(amount_str[i]=='+')
+  {
+    ++i;
+  }
+  else if(amount_str[i]=='\0') //empty string
+  {
+    return (long long int)(0);
+  }
+  //before the decimal point
+  while(amount_str[i]!='.')
+  {
+    if(amount_str[i]>='0' && amount_str[i]<='9')
+      result = result*10 + ((long long int)(amount_str[i]) - (long long int)('0'));
+    else if(amount_str[i]=='\0') //e.g. "500"
+    {
+      result *= (multiplier*100); //multiplied by 100 to get centitildecoins
+      return result;
+    }
+    else //error
+    {
+      return (long long int)(0);
+    }
+    ++i;
+  }
+  //at decimal point
+  ++i;
+  //after decimal point (i.e., tenth's place)
+  if(amount_str[i]>='0' && amount_str[i]<='9')
+    result = result*100 + ((long long int)(amount_str[i]) - (long long int)('0'))*10;
+  else if(amount_str[i]=='\0') //e.g. "500."
+  {
+    result *= (multiplier*100); //multiplied by 100 to get centitildecoins
+    return result;
+  }
+  else //error
+  {
+    return (long long int)(0);
+  }
+  //before hundredth's place
+  ++i;
+  //at hundredth's place
+  if(amount_str[i]>='0' && amount_str[i]<='9')
+  {
+    result += ((long long int)(amount_str[i]) - (long long int)('0'));
+  }
+  else if(amount_str[i]=='\0') //e.g. "500.3"
+  {
+    result *= multiplier;
+    return result;
+  }
+  else //error
+  {
+    return (long long int)(0);
+  }
+  result *= multiplier;
+  return result;
+}
+
+//custom function to convert integer string to long long int fast
+long long int strtol_fast(const char* amount_str)
+{
+  long long int result = 0;
+  int multiplier = 1;
+  int i=0;
+  if(amount_str[i]=='-')
+  {
+    multiplier = -1;
+    ++i;
+  }
+  else if(amount_str[i]=='+')
+  {
+    ++i;
+  }
+  else if(amount_str[i]=='\0') //empty string
+  {
+    return (long long int)(0);
+  }
+  //before the end of the string
+  while(amount_str[i]>='0' && amount_str[i]<='9')
+  {
+    result = result*10 + ((long long int)(amount_str[i]) - (long long int)('0'));
+    ++i;
+  }
+  result *= multiplier;
+  return result;
+}
+
+//string constant time compare (only checks for equality (return 0 if equal))
+int strctcmp(const char*a, const char*b)
+{
+  if(!(*a) || !(*b)) //a or b are empty (start with a NULL character)
+    return 1;
+
+  int r = 0;
+  for (; *a && *b; ++a, ++b)
+  {
+    r |= *a != *b;
+  }
+  return r;
+}
+
+std::string exec(const char* cmd) {
+  int i=0;
+  do
+  {
+    std::array<char, 128> buffer;
+    std::string result;
+    try
+    {
+      std::shared_ptr<FILE> pipe(popen(cmd, "r"), pclose);
+      if (!pipe)
+      {
+        ++i;
+        std::cout << "popen() failed - " << i << std::endl;
+        continue;
+      }
+
+      while (!feof(pipe.get())) {
+          if (fgets(buffer.data(), 128, pipe.get()) != nullptr)
+              result += buffer.data();
+      }
+      return result;
+    }
+    catch (const std::exception& e)
+    {
+      ++i;
+      std::cout << "popen() failed - " << i << " (exception " << e.what() << ")" << std::endl;
+      continue;
+    }
+  } while(i < 100);
+
+  throw std::runtime_error("popen() failed!");
+  return std::string(""); //dummy line, never executes
+}
+
+std::string exec2(const char* cmd, std::string input) {
+  std::string data_length_cmd_str = std::string(cmd) + std::string(PIPED_WORD_COUNT_CMD);
+  const char* data_length_cmd_cstr = data_length_cmd_str.c_str();
+  std::string data_length_str = exec(data_length_cmd_cstr);
+  long long int data_length = strtol_fast(data_length_str.c_str())+1;
+  std::vector <char> buffer;
+  buffer.reserve(data_length);
+  std::string result;
+  files_t *fp = popen2(cmd);
+  if (!fp) throw std::runtime_error("popen2() failed!");
+
+  fputs((input+std::string("\n")).c_str(), fp->in);
+  std::fflush(fp->in);
+
+  while (!feof(fp->out)) {
+      if (fgets(buffer.data(), data_length, fp->out) != nullptr)
+        result += buffer.data();
+  }
+  pclose2(fp);
+  return result;
+}
+
+long long int get_file_value(const char* file_name)
+{
+  char* file_path = new char[strlen(file_name)+sizeof(TCOIN_PATH_W_SLASH)+4];
+  std::strcpy(file_path, TCOIN_PATH_W_SLASH);
+  std::strcat(file_path, file_name);
+  std::strcat(file_path, ".txt");
+
+  std::ifstream file(file_path);
+
+  if(!file)
+  {
+    if(!strcmp(file_name, "base/base"))
+    {
+      std::cerr << "\nError! Could not open file at " << file_path << "!\n\n";
+      exit_program(ERR_GET_FILE_VALUE_COULDNT_OPEN_BASEFILE);
+    }
+    else {
+      std::cerr << "\nError! Could not open file at " << file_path << "! Assuming its internal content is \"0\\n\".\n\n";
+      return (long long int)(0);
+    }
+  }
+
+  std::ostringstream ss;
+  ss << file.rdbuf();
+
+  delete[] file_path;
+  return strtol_fast(ss.str().c_str());
+}
+
+int add_file_value(const char* file_name, const long long int &value_to_add, const long long int &base_amount)
+{
+  char* file_path = new char[strlen(file_name)+sizeof(TCOIN_PATH_W_SLASH)+4];
+  char* temp_file_path = new char[strlen(file_name)+sizeof(TCOIN_PATH_W_SLASH)+8];
+  std::strcpy(file_path, TCOIN_PATH_W_SLASH);
+  std::strcat(file_path, file_name);
+  std::strcpy(temp_file_path, file_path);
+  std::strcat(file_path, ".txt");
+  std::strcat(temp_file_path, "_tmp");
+  std::strcat(temp_file_path, ".txt");
+
+  std::ifstream file(file_path);
+
+  if(!file)
+  {
+    if(!strcmp(file_name, "base/base"))
+    {
+      std::cerr << "\nError! Could not open file at " << file_path << "!\n\n";
+      file.close();
+      delete[] file_path;
+      delete[] temp_file_path;
+      exit_program(ERR_ADD_FILE_VALUE_COULDNT_OPEN_BASEFILE);
+    }
+  }
+
+  std::ostringstream ss;
+  ss << file.rdbuf();
+
+  long long int old_value = strtol_fast(ss.str().c_str());
+
+  //sufficient funds check
+  if(value_to_add < 0 && (old_value + base_amount + value_to_add < 0))
+  {
+    file.close();
+    delete[] file_path;
+    delete[] temp_file_path;
+    return ERR_ADD_FILE_VALUE_INSUFFICIENT_FUNDS;
+  }
+
+  long long int new_value = old_value + value_to_add;
+
+  // Writing new value to file
+  file.close();
+
+
+  std::ofstream file2(temp_file_path);
+  file2 << new_value << "\n";
+  file2.close();
+
+  chmod(temp_file_path, CHMOD_PERMISSIONS);
+
+  if(!file2) //error
+  {
+    std::cerr << "Fatal error " << ERR_ADD_FILE_VALUE_FATAL << ": the file \"" << file_name << "\" was unable to be updated. Please contact " << TCOIN_ERR_CONTACT_EMAIL << " to report this error (because it requires manual recovery).";
+    exit_program(ERR_ADD_FILE_VALUE_FATAL);
+  }
+  else
+  {
+    std::remove(file_path);
+    while(1)
+    {
+      if(!std::rename(temp_file_path, file_path))
+      {
+        chmod(file_path, CHMOD_PERMISSIONS);
+        break;
+      }
+    }
+  }
+
+  delete[] file_path;
+  delete[] temp_file_path;
+  return 0;
+}
+
+std::string global_username;
+std::string get_username()
+{
+  return global_username;
+}
+int set_username(const std::string &username)
+{
+  global_username.assign(username);
+  return 0;
+}
+
+std::string formatted_amount(long long int const& amount, char const* appended_chars_default = "", char const* appended_chars_singular = "")
+{
+  std::ostringstream ss;
+
+  bool is_non_negative = amount >= 0 ? true : false;
+  if(!is_non_negative) //i.e., is negative
+    ss << "-";
+  if(((is_non_negative*2-1)*amount) % 100 == 0)
+    ss << (is_non_negative*2-1)*amount/100;
+  else if((is_non_negative*2-1)*amount % 100 < 10)
+    ss << (is_non_negative*2-1)*amount/100 << ".0" << (is_non_negative*2-1)*amount % 100;
+  else
+    ss << (is_non_negative*2-1)*amount/100 << "." << (is_non_negative*2-1)*amount % 100;
+  if(((is_non_negative*2-1)*amount == 100) && strcmp(appended_chars_singular, ""))
+    ss << appended_chars_singular;
+  else
+    ss << appended_chars_default;
+
+  std::string formatted_string(ss.str());
+  return formatted_string;
+}
+
+void cout_formatted_amount(long long int const& amount, char const* appended_chars_default = "", char const* appended_chars_singular = "", bool negative_with_parentheses = false)
+{
+  bool amount_is_negative = (amount < 0);
+  if(negative_with_parentheses && amount_is_negative) std::cout << "(";
+  std::cout << formatted_amount(amount, appended_chars_default, appended_chars_singular);
+  if(negative_with_parentheses && amount_is_negative) std::cout << ")";
+}
+
+long long int base_amount;
+long long int user_amount;
+long long int krowbar_amount[2]; //krowbar's tilde game amount
+long long int minercoin_amount[2]; //minerobber's !minercoin game amount (tilded ~username entry and non-tilded username entry, both)
+
+void show_breakdown(const long long int &amount0 = 0, char const* amount0_source = "", const long long int &amount1 = 0, char const* amount1_source = "", const long long int &amount2 = 0, char const* amount2_source = "", const long long int &amount3 = 0, char const* amount3_source = "", const long long int &amount4 = 0, char const* amount4_source = "", const long long int &amount5 = 0, char const* amount5_source = "")
+{
+  bool a0 = (amount0 != 0 && strcmp(amount0_source, ""));
+  bool a1 = (amount1 != 0 && strcmp(amount1_source, ""));
+  bool a2 = (amount2 != 0 && strcmp(amount2_source, ""));
+  bool a3 = (amount3 != 0 && strcmp(amount3_source, ""));
+  bool a4 = (amount4 != 0 && strcmp(amount4_source, ""));
+  bool a5 = (amount5 != 0 && strcmp(amount5_source, ""));
+  if(a0 || a1 || a2 || a3 || a4 || a5)
+  {
+    if(a0)
+    {
+      std::cout << amount0_source << ",";
+      cout_formatted_amount(amount0);
+      if(a1 || a2 || a3 || a4 || a5)
+      {
+        std::cout << ";";
+      }
+    }
+    if(a1)
+    {
+      std::cout << amount1_source << ",";
+      cout_formatted_amount(amount1);
+      if(a2 || a3 || a4 || a5)
+      {
+        std::cout << ";";
+      }
+    }
+    if(a2)
+    {
+      std::cout << amount2_source << ",";
+      cout_formatted_amount(amount2);
+      if(a3 || a4 || a5)
+      {
+        std::cout << ";";
+      }
+    }
+    if(a3)
+    {
+      std::cout << amount3_source << ",";
+      cout_formatted_amount(amount3);
+      if(a4 || a5)
+      {
+        std::cout << ";";
+      }
+    }
+    if(a4)
+    {
+      std::cout << amount4_source << ",";
+      cout_formatted_amount(amount4);
+      if(a5)
+      {
+        std::cout << ";";
+      }
+    }
+    if(a5)
+    {
+      std::cout << amount5_source << ",";
+      cout_formatted_amount(amount5);
+    }
+    std::cout << "\n";
+  }
+}
+
+void show_messages(const char* username)
+{
+  std::string messages_path = std::string(TCOIN_MSG_PATH) + std::string(username) + std::string("_messages.txt");
+  std::ifstream fin(messages_path.c_str());
+  char ch;
+  bool first_char_is_newline = false;
+  bool reached_eof = false;
+  for(int i=0; i < 2; ++i)
+  {
+    if(ch = fin.get())
+    {
+      if(ch == std::istream::traits_type::eof()) //https://stackoverflow.com/questions/4533063/how-does-ifstreams-eof-work
+      {
+        if(first_char_is_newline && i==1)
+        {
+          reached_eof = true;
+          std::cout << "No messages found.\n";
+        }
+        break;
+      }
+      else
+      {
+        if(i==0 && ch=='\n')
+        {
+          first_char_is_newline = true;
+        }
+        std::cout << ch;
+      }
+    }
+  }
+  if(!reached_eof)
+  {
+    std::cout << fin.rdbuf();
+  }
+
+  //removing eofbit
+  fin.clear();
+  //moving back two places from the end to read the last two characters
+  fin.seekg(-2, std::ios::end);
+  char chs[2]; //chs = characters
+  chs[0] = fin.get();
+  chs[1] = fin.get();
+  fin.get(); //to set eofbit again because I like it to be just the way it was before removing the eofbit
+  if(chs[0]!='\n' && chs[1]=='\n') //if only one newline at the end of the file
+    std::cout << "\n"; //print another one
+
+  fin.close();
+}
+
+void show_tsv_messages(const char* username) //tab-separated-value messages (tsv)
+{
+  std::string messages_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(username) + std::string("/_MESSAGES.txt");
+  std::ifstream fin(messages_path.c_str());
+  std::cout << fin.rdbuf();
+  std::cout << "\n";
+  fin.close();
+}
+
+void show_messages_tail(const char* username, int lineCount)
+{
+  size_t const granularity = 100 * lineCount;
+  std::string messages_path = std::string(TCOIN_MSG_PATH) + std::string(username) + std::string("_messages.txt");
+  std::ifstream source(messages_path.c_str(), std::ios_base::binary);
+  source.seekg(0, std::ios_base::end);
+  size_t size = static_cast<size_t>(source.tellg());
+  std::vector<char> buffer;
+  int newlineCount = 0; //pseudo newline count
+  while(source && buffer.size() != size && newlineCount <= lineCount)
+  {
+    buffer.resize(std::min(buffer.size() + granularity, size));
+    source.seekg(-static_cast<std::streamoff>(buffer.size()), std::ios_base::end);
+    source.read(buffer.data(), buffer.size());
+    newlineCount = std::count(buffer.begin(), buffer.end(), '\n');
+    for(std::vector<char>::size_type i = 0; i < (buffer.size()-1); ++i)
+      if(buffer[i] == '\n' && (buffer[i+1] == '\n' || buffer[i+1] == ' '))
+      {
+        newlineCount--; // An entry as follows: "<stuff>\n \_message>\n\n" must be treated as a single newline-ended line (and thus count 1 newline (not 3))
+        ++i; //three consecutive newlines should not be "two pairs" of newlines
+      }
+  }
+  std::vector<char>::iterator start = buffer.begin();
+  while(newlineCount > lineCount)
+  {
+    start = std::find(start, buffer.end(), '\n') + 1;
+    if(*start == ' ' || *start == '\n')
+      continue; //we're counting cutting off a '\n ' (and '\n\n') as zero (and one) newline cut off because "<stuff>\n \_message>\n\n" is one message
+    --newlineCount;
+  }
+  std::cout << "Last " << lineCount << " Messages:\n";
+  std::vector<char>::iterator end = remove(start, buffer.end(), '\r');
+  if((start == (end-1)) && (*(start) == '\n')) //there is only one character, and it is a newline (i.e.. no messages)
+    std::cout << "\nNo messages found.\n\n";
+  else
+  {
+    if(*(start) != '\n') //if it starts with a newline, don't put another one
+      std::cout << "\n";
+    std::cout << std::string(start, end);
+    if(*(end-2) != '\n' && *(end-1) == '\n') //if it ends with two newlines, don't put another one
+      std::cout << "\n";
+  }
+}
+
+void show_tsv_messages_tail(const char* username, int lineCount)
+{
+  size_t const granularity = 100 * lineCount;
+  std::string messages_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(username) + std::string("/_MESSAGES.txt");
+  std::ifstream source(messages_path.c_str(), std::ios_base::binary);
+  source.seekg(0, std::ios_base::end);
+  size_t size = static_cast<size_t>(source.tellg());
+  std::vector<char> buffer;
+  int newlineCount = 0; //pseudo newline count
+  while(source && buffer.size() != size && newlineCount <= lineCount)
+  {
+    buffer.resize(std::min(buffer.size() + granularity, size));
+    source.seekg(-static_cast<std::streamoff>(buffer.size()), std::ios_base::end);
+    source.read(buffer.data(), buffer.size());
+    newlineCount = std::count(buffer.begin(), buffer.end(), '\n');
+  }
+  std::vector<char>::iterator start = buffer.begin();
+  while(newlineCount > lineCount)
+  {
+    start = std::find(start, buffer.end(), '\n') + 1;
+    --newlineCount;
+  }
+  std::vector<char>::iterator end = remove(start, buffer.end(), '\r');
+  std::cout << std::string(start, end);
+}
+
+bool program_exists(const char* username)
+{
+  char *program_key_path = new char[strlen(username) + sizeof(PCOIN_KEY_PATH_W_SLASH) + 4]; //sizeof counts NULL char at the end too
+  std::strcpy(program_key_path, PCOIN_KEY_PATH_W_SLASH);
+  std::strcat(program_key_path, username);
+  std::strcat(program_key_path, ".txt");
+
+  std::ifstream fin(program_key_path);
+  bool return_value = false;
+
+  if(!fin) //file doesn't exist
+  {
+    fin.close();
+    delete[] program_key_path;
+
+    return_value = false; //program account not found
+  }
+  else
+  {
+    fin.close();
+    delete[] program_key_path;
+
+    return_value = true; //program account found
+  }
+
+  return return_value;
+}
+
+std::string refresh_pcoin_key()
+{
+  std::string new_key;
+  const std::string username = get_username();
+  char* program_key_path = new char[username.length() + sizeof(PCOIN_KEY_PATH_W_SLASH) + 4]; //sizeof counts NULL char at the end too
+  char* temp_program_key_path = new char[username.length() + sizeof(PCOIN_KEY_PATH_W_SLASH) + 8]; //sizeof counts NULL char at the end too
+  char* temp2_program_key_path = new char[username.length() + sizeof(PCOIN_KEY_PATH_W_SLASH) + 9]; //sizeof counts NULL char at the end too
+
+  std::strcpy(program_key_path, PCOIN_KEY_PATH_W_SLASH);
+  std::strcat(program_key_path, username.c_str());
+  std::strcpy(temp_program_key_path, program_key_path);
+  std::strcpy(temp2_program_key_path, program_key_path);
+  std::strcat(program_key_path, ".txt");
+  std::strcat(temp_program_key_path, "_tmp.txt");
+  std::strcat(temp2_program_key_path, "_tmp2.txt");
+
+  std::ifstream fin(program_key_path);
+
+  if(!fin)
+  {
+    delete[] program_key_path;
+    delete[] temp_program_key_path;
+    delete[] temp2_program_key_path;
+    return std::string("n/a");
+  }
+
+  fin.close();
+
+  if(!std::rename(program_key_path, temp_program_key_path))
+  {
+    chmod(temp_program_key_path, CHMOD_PERMISSIONS);
+    std::ofstream fin2(temp2_program_key_path);
+
+    if(!fin2)
+    {
+      fin2.close();
+      while(1)
+      {
+        if(!std::rename(temp_program_key_path, program_key_path))
+        {
+          chmod(program_key_path, CHMOD_PROGRAM_KEY_PERMISSIONS);
+          break;
+        }
+      }
+      delete[] temp2_program_key_path;
+      delete[] temp_program_key_path;
+      delete[] program_key_path;
+      return std::string("n/a");
+    }
+
+    new_key = exec(PCOIN_NEW_KEY_CMD);
+    fin2 << new_key << "\n";
+    fin2.close();
+    chmod(temp2_program_key_path, CHMOD_PROGRAM_KEY_PERMISSIONS);
+
+    while(1)
+    {
+      if(!std::rename(temp2_program_key_path, program_key_path))
+      {
+        chmod(program_key_path, CHMOD_PROGRAM_KEY_PERMISSIONS);
+        while(1)
+        {
+          if(!std::remove(temp_program_key_path))
+            break;
+        }
+        break;
+      }
+    }
+    delete[] program_key_path;
+    delete[] temp_program_key_path;
+    delete[] temp2_program_key_path;
+    return new_key;
+  }
+  else
+  {
+    delete[] program_key_path;
+    delete[] temp_program_key_path;
+    delete[] temp2_program_key_path;
+    return std::string("n/a");
+  }
+
+  delete[] program_key_path;
+  delete[] temp_program_key_path;
+  delete[] temp2_program_key_path;
+  return std::string("n/a");
+}
+
+bool username_exists(const char* username)
+{
+  const static std::string all_usernames = exec(LS_HOME_CMD);
+  std::istringstream iss(all_usernames);
+  static std::vector<std::string> usernames{std::istream_iterator<std::string>{iss}, std::istream_iterator<std::string>{}};
+  if(std::find(usernames.begin(), usernames.end(), username) != usernames.end())
+  {
+    return true;
+  }
+  return program_exists(username);
+}
+
+bool file_is_empty(std::ifstream& pFile)
+{
+    return pFile.peek() == std::ifstream::traits_type::eof();
+}
+
+bool files_are_same(const char* file_path1, const char* file_path2)
+{
+  std::ifstream fin1(file_path1);
+  if(!fin1)
+    return false;
+  std::ifstream fin2(file_path2);
+  if(!fin2)
+    return false;
+
+  char c1;
+  char c2;
+  while(fin1.get(c1) && fin2.get(c2)) //we need to go inside the loop body even if one of the reads fails, so we use || instead of &&
+  {
+    if(c2 != c1)
+      return false;
+  }
+  fin2.get(c2); //when fin1.get(c1) fails, fin2.get(c2) is not executed because of short-circuited boolean operators. This line compensates for that.
+  if(fin1 || fin2) //one of the files must still be valid while both files are not simulatenously valid (after the while loop), which means the files are of different sizes
+    return false;
+
+  return true;
+  //Because of (!fin1 && fin2) || (fin1 && !fin2), if any one
+  //file is larger than the other, the files are deemed not the same.
+  //If the last characters of the two files have not been read, then
+  //both "fin1" and "fin2" will return true in the next iteration, and
+  //in the current iteration, c1 and c2 have valid values that can be compared.
+  //If the last characters of the two files were read, then "fin1" and "fin2"
+  //will still return true until the next time fin1.get() or fin2.get() is called.
+  //c1 and c2 still carry valid values (namely, the last characters of fin1 and fin2)
+  //which are compared. At the next iteration, both fin1 and fin2 fail and the loop exits.
+  //This means all c1's and c2's were equal in the iterations before. Thus, the two files are
+  //deemed the same.
+}
+
+int send_message(const char* sender_username, const char* receiver_username, const char* message, const long long int &amount_sent, const char* option)
+{
+  std::string random_string = std::to_string(rand());
+
+  char *receiver_path = new char[strlen(receiver_username) + sizeof(TCOIN_MSG_PATH) + 13]; //sizeof() includes '\0'
+  char *temp_receiver_path = new char[strlen(receiver_username) + strlen(random_string.c_str()) + sizeof(TCOIN_MSG_PATH) + 13];
+
+  std::strcpy(receiver_path, TCOIN_MSG_PATH);
+  std::strcat(receiver_path, receiver_username);
+  std::strcat(receiver_path, "_messages.txt"); // length = 13
+
+  std::strcpy(temp_receiver_path, TCOIN_MSG_PATH);
+  std::strcat(temp_receiver_path, receiver_username);
+  std::strcat(temp_receiver_path, random_string.c_str());
+  std::strcat(temp_receiver_path, "_messages.txt"); // length = 13
+
+  //create receiver's message file if none exists
+  //the message will be included in the receiver's
+  //account when she/he initialises her/his account
+  //at a later time
+
+  char *receiver_salt_path = new char[strlen(receiver_username) + sizeof(TCOIN_SALT_PATH) + 9];
+  char *receiver_salt_logged_in_path = new char[strlen(receiver_username) + sizeof(TCOIN_SALT_PATH) + 19];
+  std::strcpy(receiver_salt_path, TCOIN_SALT_PATH);
+  std::strcat(receiver_salt_path, receiver_username);
+  std::strcpy(receiver_salt_logged_in_path, receiver_salt_path);
+  std::strcat(receiver_salt_path, "_salt.txt"); // length = 9
+  std::strcat(receiver_salt_logged_in_path, "_salt_logged_in.txt"); // length = 19
+
+  std::ifstream fin(receiver_path);
+  std::ifstream fin2(receiver_salt_path);
+  std::ifstream fin3(receiver_salt_logged_in_path);
+
+  if((!fin || file_is_empty(fin)) && ((!program_exists(receiver_username)) || ((!fin2 || file_is_empty(fin2)) && (!fin3 || file_is_empty(fin3)))))
+  {
+    fin.close();
+    std::ofstream fout(receiver_path, std::fstream::trunc);
+    fout << "\n";
+    fout.close();
+  }
+  else
+    fin.close();
+  fin2.close();
+  fin3.close();
+
+  chmod(receiver_path, CHMOD_PERMISSIONS);
+
+  delete[] receiver_salt_path;
+  delete[] receiver_salt_logged_in_path;
+
+  while(1)
+  {
+    if(!std::rename(receiver_path, temp_receiver_path))
+    {
+      char *really_temp_receiver_path = new char[strlen(temp_receiver_path) + 5];
+      std::strcpy(really_temp_receiver_path, temp_receiver_path);
+      std::strcat(really_temp_receiver_path, "_tmp");
+
+      std::ifstream fin(temp_receiver_path);
+      std::ofstream fout(really_temp_receiver_path);
+
+      if(!file_is_empty(fin))
+        fout << fin.rdbuf();
+      fin.close();
+
+      time_t now = std::time(NULL);
+      char dt[26];
+      #ifndef TILDEINSTITUTE
+        std::strftime(dt, 26, "%a %b %_d %T %Y", std::gmtime(&now));
+      #else
+        std::strftime(dt, 26, "%a %b %e %T %Y", std::gmtime(&now));
+      #endif
+      char sender_formatted_string[26];
+      char sender_arrow_formatted_string[47];
+      char sender_arrow_string[47];
+      char receiver_formatted_string[26];
+      std::snprintf(sender_formatted_string, 26, "%25s", sender_username);
+      std::snprintf(receiver_formatted_string, 26, "%-25s", receiver_username);
+      int sender_username_length = std::strlen(sender_username);
+      int number_of_chars = 26 >= sender_username_length ? 26 : sender_username_length;
+      std::strncpy(sender_arrow_string, sender_username, number_of_chars);
+      sender_arrow_string[number_of_chars] = '\0';
+      std::strcat(sender_arrow_string, " ----");
+      std::string amount_sent_str = formatted_amount(amount_sent);
+      std::strncat(sender_arrow_string, amount_sent_str.c_str(), 10);
+      std::strcat(sender_arrow_string, "----> ");
+      std::snprintf(sender_arrow_formatted_string, 47, "%46s", sender_arrow_string);
+      fout << dt << ": " << sender_arrow_formatted_string << receiver_username;
+      if(!strcmp(message, "")) //if message is empty
+        fout << "\n";
+      else
+      {
+        fout << "\n \\_ " << sender_username << " said: ";
+        for(int i=0; message[i]!='\0'; ++i)
+        {
+          if(message[i] == '\n')
+            fout << "<new-line>"; //return-key pressed
+          else if(message[i] == '\v')
+            fout << "<vertical-tab>"; //vertical-tab symbol entered
+          else
+            fout << message[i];
+        }
+        fout << "\n\n";
+      }
+      fout.close();
+      chmod(really_temp_receiver_path, CHMOD_PERMISSIONS);
+
+      if(!fout) //error
+      {
+        std::cerr << "Fatal error " << ERR_SEND_MESSAGE_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL << ": the receiver message file was unable to be updated. Please contact " << TCOIN_ERR_CONTACT_EMAIL << " to report this error (because it requires manual recovery).";
+        exit_program(ERR_SEND_MESSAGE_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL);
+      }
+      else
+      {
+        std::remove(temp_receiver_path);
+      }
+
+      while(1)
+      {
+        if(!std::rename(really_temp_receiver_path, temp_receiver_path))
+          break;
+      }
+
+      // unlock_receiver_messages
+      while(1)
+      {
+        if(!std::rename(temp_receiver_path, receiver_path))
+          break;
+      }
+
+      chmod(receiver_path, CHMOD_PERMISSIONS);
+
+      delete[] really_temp_receiver_path;
+      delete[] temp_receiver_path;
+      delete[] receiver_path;
+
+      //additional place to write if sending to a program:
+      if(program_exists(receiver_username))
+      {
+        random_string = std::string("rand");
+        std::string program_receiver_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/_MESSAGES.txt");
+        std::string temp_program_receiver_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/_MESSAGES") + random_string + std::string(".txt");
+        std::string really_temp_program_receiver_path = temp_program_receiver_path + std::string("_tmp");
+
+        //create program receiver's _MESSAGES file if none exists
+        {
+          std::ifstream fin(program_receiver_path.c_str());
+          std::ifstream fin2(temp_program_receiver_path.c_str());
+          if((!fin || file_is_empty(fin)) && (!fin2))
+          {
+            fin.close();
+            std::ofstream fout(program_receiver_path.c_str(), std::fstream::trunc);
+            fout << "\n";
+            fout.close();
+          }
+          else
+            fin.close();
+          fin2.close();
+          chmod(program_receiver_path.c_str(), CHMOD_PERMISSIONS);
+        }
+
+        while(1)
+        {
+          if(!std::rename(program_receiver_path.c_str(), temp_program_receiver_path.c_str()))
+          {
+            std::ifstream fin(temp_program_receiver_path.c_str());
+            std::ofstream fout(really_temp_program_receiver_path.c_str());
+
+            if(!file_is_empty(fin))
+              fout << fin.rdbuf();
+            fin.close();
+
+            //now, sender_username, receiver_username, amount_sent
+            char sender_formatted_string[26];
+            char receiver_formatted_string[26];
+            std::snprintf(sender_formatted_string, 26, "%s", sender_username);
+            std::snprintf(receiver_formatted_string, 26, "%s", receiver_username);
+            std::string amount_sent_str = formatted_amount(amount_sent);
+            fout << now << "\t" << sender_formatted_string << "\t" << receiver_formatted_string << "\t" << amount_sent_str;
+            if(!strcmp(message, "")) //if message is empty
+              fout << "\n";
+            else
+            {
+              fout << "\t" << sender_formatted_string << "\t";
+              for(int i=0; message[i]!='\0'; ++i)
+              {
+                if(message[i] == '\n')
+                  fout << "<new-line>"; //return-key pressed
+                else if(message[i] == '\v')
+                  fout << "<vertical-tab>"; //vertical-tab symbol entered
+                else
+                  fout << message[i];
+              }
+              fout << "\n";
+            }
+            fout.close();
+            chmod(really_temp_program_receiver_path.c_str(), CHMOD_PERMISSIONS);
+
+            if(!fout) //error
+            {
+              std::cerr << "Fatal error " << ERR_SEND_MESSAGE_PROGRAM_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL << ": the receiver program_message file was unable to be updated. Please contact " TCOIN_ERR_CONTACT_EMAIL " to report this error (because it requires manual recovery).";
+              exit_program(ERR_SEND_MESSAGE_PROGRAM_RECEIVER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL);
+            }
+            else
+            {
+              std::remove(temp_program_receiver_path.c_str());
+            }
+
+            while(1)
+            {
+              if(!std::rename(really_temp_program_receiver_path.c_str(), temp_program_receiver_path.c_str()))
+              break;
+            }
+
+            // unlock_receiver_program_messages
+            while(1)
+            {
+              if(!std::rename(temp_program_receiver_path.c_str(), program_receiver_path.c_str()))
+                break;
+            }
+
+            chmod(program_receiver_path.c_str(), CHMOD_PERMISSIONS);
+            break;
+          }//if statement with !std::rename for receiver's program accounting _messages file
+        }//while loop for program accounting receiver's _messages file
+      }//receiver is program account
+
+      //locking sender_messages_after_receiver_messages_unlocked
+
+      random_string = std::to_string(rand());
+
+      char *sender_path = new char[strlen(sender_username) + sizeof(TCOIN_MSG_PATH) + 13];
+      char *temp_sender_path = new char[strlen(sender_username) + strlen(random_string.c_str()) + sizeof(TCOIN_MSG_PATH) + 13];
+
+      std::strcpy(sender_path, TCOIN_MSG_PATH);
+      std::strcat(sender_path, sender_username);
+      std::strcat(sender_path, "_messages.txt"); // length = 13
+
+      std:strcpy(temp_sender_path, TCOIN_MSG_PATH);
+      std::strcat(temp_sender_path, sender_username);
+      std::strcat(temp_sender_path, random_string.c_str());
+      std::strcat(temp_sender_path, "_messages.txt"); // length = 13
+
+      while(1)
+      {
+        if(!std::rename(sender_path, temp_sender_path))
+        {
+          char *really_temp_sender_path = new char[strlen(temp_sender_path) + 5];
+          std::strcpy(really_temp_sender_path, temp_sender_path);
+          std::strcat(really_temp_sender_path, "_tmp");
+
+          fin.open(temp_sender_path);
+          fout.open(really_temp_sender_path);
+          chmod(really_temp_sender_path, CHMOD_PERMISSIONS);
+
+          fout << fin.rdbuf();
+
+          now = std::time(NULL);
+          #ifndef TILDEINSTITUTE
+             std::strftime(dt, 26, "%a %b %_d %T %Y", std::gmtime(&now));
+          #else
+             std::strftime(dt, 26, "%a %b %e %T %Y", std::gmtime(&now));
+          #endif
+          char sender_formatted_string_right_aligned[26];
+          char receiver_arrow_formatted_string[47];
+          char receiver_arrow_string[47];
+          std::snprintf(receiver_formatted_string, 26, "%25s", receiver_username);
+          std::snprintf(sender_formatted_string, 26, "%-25s", sender_username);
+          std::snprintf(sender_formatted_string_right_aligned, 26, "%25s", sender_username);
+          int receiver_username_length = std::strlen(receiver_username);
+          int number_of_chars = 26 >= receiver_username_length ? 26 : receiver_username_length;
+          std::strncpy(receiver_arrow_string, receiver_username, number_of_chars);
+          receiver_arrow_string[number_of_chars] = '\0';
+          std::strcat(receiver_arrow_string, " <---");
+          std::string amount_sent_str = formatted_amount(amount_sent);
+          std::strncat(receiver_arrow_string, amount_sent_str.c_str(), 10);
+          std::strcat(receiver_arrow_string, "----- ");
+          std::snprintf(receiver_arrow_formatted_string, 47, "%46s", receiver_arrow_string);
+          fout << dt << ": " << receiver_arrow_formatted_string << sender_username;
+          if(!strcmp(message, "")) //if message is empty
+            fout << "\n";
+          else
+          {
+            fout << "\n \\_ " << sender_username << " said: ";
+            for(int i=0; message[i]!='\0'; ++i)
+            {
+              if(message[i] == '\n')
+                fout << "<new-line>"; //return-key pressed
+              else if(message[i] == '\v')
+                fout << "<vertical-tab>"; //vertical-tab symbol entered
+              else
+                fout << message[i];
+            }
+            fout << "\n\n";
+          }
+
+          fin.close();
+          fout.close();
+
+          if(!fout) //error
+          {
+            std::cerr << "Fatal error " << ERR_SEND_MESSAGE_SENDER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL << ": the sender message file was unable to be updated. Please contact " << TCOIN_ERR_CONTACT_EMAIL << " to report this error (because it requires manual recovery).";
+            exit_program(ERR_SEND_MESSAGE_SENDER_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL);
+          }
+          else
+          {
+            std::remove(temp_sender_path);
+          }
+
+          while(1)
+          {
+            if(!std::rename(really_temp_sender_path, temp_sender_path))
+              break;
+          }
+
+          while(1)
+          {
+            if(!std::rename(temp_sender_path, sender_path))
+              break;
+          }
+
+          delete[] really_temp_sender_path;
+          delete[] temp_sender_path;
+          delete[] sender_path;
+
+          //additional place to write if sending from a program:
+          if(program_exists(sender_username))
+          {
+            random_string = std::string("rand");
+            std::string program_sender_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/_MESSAGES.txt");
+            std::string temp_program_sender_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/_MESSAGES") + random_string + std::string(".txt");
+            std::string really_temp_program_sender_path = temp_program_sender_path + std::string("_tmp");
+
+            //create program sender's _MESSAGES file if none exists
+            {
+              std::ifstream fin(program_sender_path.c_str());
+              std::ifstream fin2(temp_program_sender_path.c_str());
+              if((!fin || file_is_empty(fin)) && (!fin2))
+              {
+                fin.close();
+                std::ofstream fout(program_sender_path.c_str(), std::fstream::trunc);
+                fout << "\n";
+                fout.close();
+              }
+              else
+                fin.close();
+              fin2.close();
+              chmod(program_sender_path.c_str(), CHMOD_PERMISSIONS);
+            }
+
+            while(1)
+            {
+              if(!std::rename(program_sender_path.c_str(), temp_program_sender_path.c_str()))
+              {
+                std::ifstream fin(temp_program_sender_path.c_str());
+                std::ofstream fout(really_temp_program_sender_path.c_str());
+
+                if(!file_is_empty(fin))
+                  fout << fin.rdbuf();
+                fin.close();
+
+                //now (updated by code above to reflect "sending time"), sender_username, receiver_username, amount_sent
+                char sender_formatted_string[26];
+                char receiver_formatted_string[26];
+                std::snprintf(sender_formatted_string, 26, "%s", sender_username);
+                std::snprintf(receiver_formatted_string, 26, "%s", receiver_username);
+                std::string amount_sent_str = formatted_amount(-1*amount_sent);
+                fout << now << "\t" << receiver_formatted_string << "\t" << sender_formatted_string << "\t" << amount_sent_str;
+                if(!strcmp(message, "")) //if message is empty
+                  fout << "\n";
+                else
+                {
+                  fout << "\t" << sender_formatted_string << "\t";
+                  for(int i=0; message[i]!='\0'; ++i)
+                  {
+                    if(message[i] == '\n')
+                      fout << "<new-line>"; //return-key pressed
+                    else if(message[i] == '\v')
+                      fout << "<vertical-tab>"; //vertical-tab symbol entered
+                    else
+                      fout << message[i];
+                  }
+                  fout << "\n";
+                }
+                fout.close();
+                chmod(really_temp_program_sender_path.c_str(), CHMOD_PERMISSIONS);
+
+                if(!fout) //error
+                {
+                  std::cerr << "Fatal error " << ERR_SEND_MESSAGE_SENDER_PROGRAM_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL << ": the sender program message file was unable to be updated. Please contact " << TCOIN_ERR_CONTACT_EMAIL << " to report this error (because it requires manual recovery).";
+                  exit_program(ERR_SEND_MESSAGE_SENDER_PROGRAM_MSG_FILE_UNABLE_TO_BE_UPDATED_FATAL);
+                }
+                else
+                {
+                  std::remove(temp_program_sender_path.c_str());
+                }
+
+                while(1)
+                {
+                  if(!std::rename(really_temp_program_sender_path.c_str(), temp_program_sender_path.c_str()))
+                  break;
+                }
+
+                // unlock_sender_program_messages
+                while(1)
+                {
+                  if(!std::rename(temp_program_sender_path.c_str(), program_sender_path.c_str()))
+                    break;
+                }
+
+                chmod(program_sender_path.c_str(), CHMOD_PERMISSIONS);
+                break;
+              }//if statement with !std::rename for sender's program accounting _messages file
+            }//while loop for program accounting sender's _messages file
+          }//sender is program account
+
+          break;
+        }
+      }
+
+      break;
+    }
+  }
+  //finally, everything ran well and we can send the message to stdout if verbose is turned on
+  if(!strcmp(option, "verbose") && strcmp(message, "")) //message should not be empty
+  {
+    //since the message to stdout from send() ends with "\n\n", we have commented this below line out
+    //std::cout << "\n";
+    std::cout << "In addition, the transaction message \"" << message << "\" was ";
+    std::cout << "sent from `" << sender_username << "` to `" << receiver_username << "` successfully.";
+    std::cout << "\n\n";
+  }
+  return 0;
+}
+
+bool user_is_locked(const char* username)
+{
+  std::ifstream fin((std::string(TCOIN_PATH_W_SLASH) + std::string(username) + std::string("_locked.txt")).c_str());
+  if(!fin)
+    return false;
+  return true;
+}
+
+int send(const char* sender_username, const char* receiver_username, const long long int &amount_to_send, const long long int &base_amount, const char* option)
+{
+  int final_return_value = 0;
+
+  //receiver usrname check
+  if(username_exists(receiver_username))
+  {
+    if(!strcmp(sender_username, receiver_username))
+    {
+      std::cout << "\nSorry, you cannot send tildecoins to yourself.\n\n";
+      return ERR_TCOIN_TO_SELF;
+    }
+    if(user_is_locked(receiver_username))
+    {
+      if(!strcmp(option, "verbose"))
+        std::cout << "\nSorry, `" << receiver_username << "` does not wish to receive any tildecoins at this time.\n\n";
+      return ERR_RECEIVER_BLOCKED;
+    }
+    if(amount_to_send <= 0)
+    {
+      if(!strcmp(option, "verbose"))
+        std::cout << "\nSorry, that amount is not valid. The amount should be a positive decimal number when truncated to two decimal places.\n\n";
+      return ERR_NEGATIVE_SEND_AMOUNT;
+    }
+    else
+    {
+      std::string random_string = std::to_string(rand());
+      int return_value = -1;
+
+      //additional place to deduct from if the sender is a program (which is
+      //always the case when `pcoin` is used, but we'll check anyway
+      //we do this before the "tcoin send" part so that if program tries to send
+      //more than it owes receiver, it's checked before checking "tcoin send's"
+      //conditions
+      if(program_exists(sender_username))
+      {
+        random_string = std::string("rand"); //not really random
+        std::string program_sender_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/") + std::string(receiver_username) + std::string(".txt");
+        std::string temp_program_sender_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/") + std::string(receiver_username) + random_string + std::string(".txt");
+        std::string temp_program_sender_username = std::string(PROG_ACT_W_SLASH) + std::string(sender_username) + std::string("/") + std::string(receiver_username) + random_string;
+
+        //create program sender's "receiver's balance file" if none exists
+        {
+          std::ifstream fin(program_sender_path.c_str());
+          std::ifstream fin2(temp_program_sender_path.c_str());
+          #if DEBUG
+            std::cout << program_sender_path << "," << temp_program_sender_path << "," << !fin << "," << file_is_empty(fin) << "," << !fin2 << std::endl;
+          #endif
+          if((!fin || file_is_empty(fin)) && (!fin2))
+          {
+            fin.close();
+            std::ofstream fout(program_sender_path.c_str(), std::fstream::trunc);
+            fout << "0\n";
+            fout.close();
+            #if DEBUG
+              char dummy;
+              std::cout << "Press enter to continue"; std::cin >> dummy;
+            #endif
+          }
+          else
+            fin.close();
+          fin2.close();
+          chmod(program_sender_path.c_str(), CHMOD_PERMISSIONS);
+        }
+
+        while(1)
+        {
+          if(!std::rename(program_sender_path.c_str(), temp_program_sender_path.c_str()))
+          {
+            //Insufficient funds check in add_file_value() itself
+            //third argument, base_amount, is 0 because program
+            //should not be allowed to send more than what is owed
+            //to the receiver
+            return_value = add_file_value(temp_program_sender_username.c_str(), -1 * amount_to_send, 0);
+
+            //The same amount must also be deducted from the "_total.txt" file
+            //which records the total amount owed to others
+            if(return_value == 0)
+            {
+              random_string = std::string("rand");
+              std::string program_sender_total_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/_TOTAL.txt");
+              std::string temp_program_sender_total_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(sender_username) + std::string("/_TOTAL") + random_string + std::string(".txt");
+              std::string temp_program_sender_total_username = std::string(PROG_ACT_W_SLASH) + std::string(sender_username) + std::string("/_TOTAL") + random_string;
+
+              //create program sender's "total balance file" if none exists
+              {
+                std::ifstream fin(program_sender_total_path.c_str());
+                std::ifstream fin2(temp_program_sender_total_path.c_str());
+                if((!fin || file_is_empty(fin)) && (!fin2))
+                {
+                  fin.close();
+                  std::ofstream fout(program_sender_total_path.c_str(), std::fstream::trunc);
+                  fout << "0\n";
+                  fout.close();
+                }
+                else
+                  fin.close();
+                fin2.close();
+                chmod(program_sender_total_path.c_str(), CHMOD_PERMISSIONS);
+              }
+
+              while(1)
+              {
+                if(!std::rename(program_sender_total_path.c_str(), temp_program_sender_total_path.c_str()))
+                {
+                  //Insufficient funds check in add_file_value() itself
+                  //third argument, base_amount, is 0 because program
+                  //should not be allowed to send more than what is owed
+                  //to the receiver
+                  add_file_value(temp_program_sender_total_username.c_str(), -1 * amount_to_send, 0);
+
+                  random_string = std::to_string(rand());
+
+                  // sizeof() includes '\0'
+                  char* temp_sender_path = new char[strlen(sender_username) + strlen(random_string.c_str()) + sizeof(TCOIN_PATH_W_SLASH) + 4];
+                  char* sender_path = new char[strlen(sender_username) + sizeof(TCOIN_PATH_W_SLASH) + 4];
+                  char* temp_sender_username = new char[strlen(sender_username) + strlen(random_string.c_str()) + 1];
+
+                  std::strcpy(temp_sender_username, sender_username);
+                  std::strcat(temp_sender_username, random_string.c_str());
+
+                  std::strcpy(temp_sender_path, TCOIN_PATH_W_SLASH);
+                  std::strcat(temp_sender_path, temp_sender_username);
+                  std::strcat(temp_sender_path, ".txt"); // length = 4
+
+                  std::strcpy(sender_path, TCOIN_PATH_W_SLASH);
+                  std::strcat(sender_path, sender_username);
+                  std::strcat(sender_path, ".txt"); // length = 4
+
+                  while(1)
+                  {
+                    if(!std::rename(sender_path, temp_sender_path))
+                    {
+                      //Insufficient funds check is in add_file_value()
+                      return_value = add_file_value(temp_sender_username, -1 * amount_to_send, base_amount);
+
+                      if(return_value == 0) // Funds sucessfully deducted from sender_username
+                      {
+                        random_string = std::string("rand");
+
+                        // sizeof() includes '\0'
+                        char *temp_receiver_path = new char[strlen(receiver_username) + strlen(random_string.c_str()) + sizeof(TCOIN_PATH_W_SLASH) + 4];
+                        char *receiver_path = new char[strlen(receiver_username) + sizeof(TCOIN_PATH_W_SLASH) + 4];
+                        char *temp_receiver_username = new char[strlen(receiver_username) + strlen(random_string.c_str()) + 1];
+
+                        std::strcpy(temp_receiver_username, receiver_username);
+                        std::strcat(temp_receiver_username, random_string.c_str());
+
+                        std::strcpy(temp_receiver_path, TCOIN_PATH_W_SLASH);
+                        std::strcat(temp_receiver_path, temp_receiver_username);
+                        std::strcat(temp_receiver_path, ".txt");
+
+                        std::strcpy(receiver_path, TCOIN_PATH_W_SLASH);
+                        std::strcat(receiver_path, receiver_username);
+                        std::strcat(receiver_path, ".txt");
+
+                        //create receiver's balance file if none exists
+                        //the balance will be included in the receiver's
+                        //account when she/he initialises her/his account
+                        //at a later time
+                        char *receiver_salt_path = new char[strlen(receiver_username) + sizeof(TCOIN_SALT_PATH) + 9]; // sizeof() includes '\0'
+                        char *receiver_salt_logged_in_path = new char[strlen(receiver_username) + sizeof(TCOIN_SALT_PATH) + 19];
+                        std::strcpy(receiver_salt_path, TCOIN_SALT_PATH);
+                        std::strcat(receiver_salt_path, receiver_username);
+                        std::strcpy(receiver_salt_logged_in_path, receiver_salt_path);
+                        std::strcat(receiver_salt_path, "_salt.txt"); // length = 9
+                        std::strcat(receiver_salt_logged_in_path, "_salt_logged_in.txt"); // length = 19
+
+                        std::ifstream fin(receiver_path);
+                        std::ifstream fin2(receiver_salt_path);
+                        std::ifstream fin3(receiver_salt_logged_in_path);
+
+                        if((!fin || file_is_empty(fin)) && ((!program_exists(receiver_username)) || ((!fin2 || file_is_empty(fin2)) && (!fin3 || file_is_empty(fin3)))))
+                        {
+                          fin.close();
+                          std::ofstream fout(receiver_path, std::fstream::trunc);
+                          fout << "0\n";
+                          fout.close();
+                        }
+                        else
+                          fin.close();
+                        fin2.close();
+                        fin3.close();
+
+                        chmod(receiver_path, CHMOD_PERMISSIONS);
+
+                        delete[] receiver_salt_path;
+                        delete[] receiver_salt_logged_in_path;
+
+                        while(1)
+                        {
+                          if(!std::rename(receiver_path, temp_receiver_path))
+                          {
+                            //Insufficient funds check in add_file_value() itself
+                            add_file_value(temp_receiver_username, amount_to_send, base_amount);
+
+                            //additional place to write if sending to a program:
+                            if(program_exists(receiver_username))
+                            {
+                              random_string = std::string("rand");
+                              std::string program_receiver_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/") + std::string(sender_username) + std::string(".txt");
+                              std::string temp_program_receiver_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/") + std::string(sender_username) + random_string + std::string(".txt");
+                              std::string temp_program_receiver_username = std::string(PROG_ACT_W_SLASH) + std::string(receiver_username) + std::string("/") + std::string(sender_username) + random_string;
+
+                              //create program receiver's balance file if none exists
+                              {
+                                std::ifstream fin(program_receiver_path.c_str());
+                                std::ifstream fin2(temp_program_receiver_path.c_str());
+                                if((!fin || file_is_empty(fin)) && (!fin2))
+                                {
+                                  fin.close();
+                                  std::ofstream fout(program_receiver_path.c_str(), std::fstream::trunc);
+                                  fout << "0\n";
+                                  fout.close();
+                                }
+                                else
+                                  fin.close();
+                                fin2.close();
+                                chmod(program_receiver_path.c_str(), CHMOD_PERMISSIONS);
+                              }
+
+                              while(1)
+                              {
+                                if(!std::rename(program_receiver_path.c_str(), temp_program_receiver_path.c_str()))
+                                {
+                                  //Insufficient funds check in add_file_value() itself
+                                  add_file_value(temp_program_receiver_username.c_str(), amount_to_send, base_amount);
+
+                                  //Value must also be added to a _total.txt file
+                                  {
+                                    random_string = std::string("rand");
+                                    std::string program_receiver_total_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/_TOTAL.txt");
+                                    std::string temp_program_receiver_total_path = std::string(TCOIN_PROG_ACT_PATH) + std::string(receiver_username) + std::string("/_TOTAL")  + random_string + std::string(".txt");
+                                    std::string temp_program_receiver_total_username = std::string(PROG_ACT_W_SLASH) + std::string(receiver_username) + std::string("/_TOTAL") + random_string;
+
+                                    //create program receiver's "total balance file" if none exists
+                                    {
+                                      std::ifstream fin(program_receiver_total_path.c_str());
+                                      std::ifstream fin2(temp_program_receiver_total_path.c_str());
+                                      if((!fin || file_is_empty(fin)) && (!fin2))
+                                      {
+                                        fin.close();
+                                        std::ofstream fout(program_receiver_total_path.c_str(), std::fstream::trunc);
+                                        fout << "0\n";
+                                        fout.close();
+                                      }
+                                      else
+                                        fin.close();
+                                      fin2.close();
+                                      chmod(program_receiver_total_path.c_str(), CHMOD_PERMISSIONS);
+                                    }
+
+                                    while(1)
+                                    {
+                                      if(!std::rename(program_receiver_total_path.c_str(), temp_program_receiver_total_path.c_str()))
+                                      {
+                                        //Insufficient funds check in add_file_value() itself
+                                        add_file_value(temp_program_receiver_total_username.c_str(), amount_to_send, base_amount);
+                                        while(1)
+                                        {
+                                          if(!std::rename(temp_program_receiver_total_path.c_str(), program_receiver_total_path.c_str()))
+                                            break;
+                                        }
+                                        break;
+                                      }
+                                    }
+                                  }
+
+                                  while(1)
+                                  {
+                                    if(!std::rename(temp_program_receiver_path.c_str(), program_receiver_path.c_str()))
+                                      break;
+                                  }
+                                  break;
+                                }
+                              }
+                            }
+
+                            if(!strcmp(option, "verbose"))
+                            {
+                              std::cout << "\n";
+                              cout_formatted_amount(amount_to_send, " tildecoins were ", " tildecoin was ");
+                              std::cout << "sent from `" << sender_username << "` to `" << receiver_username << "`.";
+                              std::cout << "\n\n";
+                            }
+
+                            while(1)
+                            {
+                              if(!std::rename(temp_receiver_path, receiver_path))
+                                break;
+                            }
+                            delete[] temp_receiver_path;
+                            delete[] receiver_path;
+                            delete[] temp_receiver_username;
+                            break;
+                          }
+                        }
+                      }
+                      else if(return_value == 1)
+                      {
+                        if(!strcmp(option, "verbose"))
+                        {
+                          long long int amount_of_funds = base_amount + get_file_value(temp_sender_username);
+                          std::cout << "\nSorry, you do not have sufficient funds to execute this transaction. ";
+                          std::cout << "Your current balance is ";
+                          cout_formatted_amount(amount_of_funds, " tildecoins.\n\n", " tildecoin.\n\n");
+                        }
+                        final_return_value = ERR_INSUFFICIENT_FUNDS; //we don't simply "return 3" here because we want temp_sender_path to get renamed again
+                      }
+
+                      while(1)
+                      {
+                        if(!std::rename(temp_sender_path, sender_path))
+                          break;
+                      }
+
+                      delete[] temp_sender_path;
+                      delete[] sender_path;
+                      delete[] temp_sender_username;
+                      break;
+                    }
+                  }
+
+                  while(1)
+                  {
+                    if(!std::rename(temp_program_sender_total_path.c_str(), program_sender_total_path.c_str()))
+                      break;
+                  }
+                  break;
+                }
+              }
+            }
+            else if(return_value == 1)
+            {
+              long long int amount_owed = get_file_value(temp_program_sender_username.c_str());
+              long long int amount_to_aib = (long long int)(amount_to_send) - amount_owed;
+              std::cout << "\nSorry, you only owe `" << receiver_username << "` ";
+              cout_formatted_amount(amount_owed, " tildecoins", " tildecoin");
+              std::cout << ", not ";
+              cout_formatted_amount(amount_to_send, " tildecoins. ", " tildecoin. ");
+              std::cout << "Please run `" << PCOIN_BIN_PATH_W_SPACE << "add_internal_balance " << receiver_username << " ";
+              cout_formatted_amount(amount_to_aib);
+              std::cout << "` to sufficiently increase the amount owed to `" << receiver_username << "`.\n\n";
+
+              final_return_value = ERR_INSUFFICIENT_FUNDS; //we don't simply "return 3" here because we want temp_program_sender_path to get renamed again
+            }
+
+            while(1)
+            {
+              if(!std::rename(temp_program_sender_path.c_str(), program_sender_path.c_str()))
+                break;
+            }
+            break;
+          }
+        }
+      }
+    }
+  }
+  else
+  {
+    if(!strcmp(option, "verbose"))
+      std::cout << "\nSorry, no user with the username `" << receiver_username << "` was found.\n\n";
+    return ERR_RECEIVER_NOT_FOUND;
+  }
+
+  return final_return_value;
+}
+
+void help()
+{
+  std::cout <<"\npcoin is meant for programs. After each of the following commands, you will have to input a valid key to stdin.";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "messages` or `" << PCOIN_BIN_PATH_W_SPACE << "-m`: check your messages";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "messages <num>` or `" << PCOIN_BIN_PATH_W_SPACE << "-m <num>`: print the last <num> messages";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "messages_tsv` or `" << PCOIN_BIN_PATH_W_SPACE << "-mtsv`: check your messages in tab-separated-values format";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "messages_tsv <num>` or `" << PCOIN_BIN_PATH_W_SPACE << "-mtsv <num>`: print the last <num> messages in tab-separated-values format";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "balance` or `" << PCOIN_BIN_PATH_W_SPACE << "-b`: print the number representing your balance";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "total_owed` or `" << PCOIN_BIN_PATH_W_SPACE << "-to`: print the total amount owed to others";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "internal_balance <username>` or `" << PCOIN_BIN_PATH_W_SPACE << "-ib <username>`: print the amount you owe <username>";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "add_internal_balance <username>` or `" << PCOIN_BIN_PATH_W_SPACE << "-aib <username> <amount>`: add <amount> to the amount you owe <username>";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "send <username> <amount>` or `" << PCOIN_BIN_PATH_W_SPACE  << "-s <username> <amount>`: send <amount> tildecoins to <username>";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "send <username> <amount> \"<message>\"` or `" << PCOIN_BIN_PATH_W_SPACE << "-s <username> <amount> \"<message>\"`: optionally, include a message to be sent to <username>";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "silentsend <username> <amount> [\"<message>\"]`, `" << PCOIN_BIN_PATH_W_SPACE << "send -s <username> <amount> [\"<message>\"]` or `" << PCOIN_BIN_PATH_W_SPACE << "-ss <username> <amount> [\"<message>\"]`: send <amount> tildecoins to <username> with an optional (as indicated by [ and ], which should not be included in the actual comment) message included without printing anything";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "refresh_key` or `" << PCOIN_BIN_PATH_W_SPACE << "-rk`: generate a new key for your pcoin account and print it";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "name` or `" << PCOIN_BIN_PATH_W_SPACE << "-n`: print the name on the account";
+  std::cout << "\nIn the commands with `<username> <amount>`, switching the two arguments around (i.e., from `<username> <amount>` to `<amount> <username>`) will also work";
+  std::cout << "\n`" << PCOIN_BIN_PATH_W_SPACE << "--help`, `" << PCOIN_BIN_PATH_W_SPACE << "help` or `" << PCOIN_BIN_PATH_W_SPACE << "-h`: print this help text";
+  std::cout << "\nSend an email to " << TCOIN_PASS_RESET_CONTACT_EMAIL << " to report any errors or request a key for your program.\n\n";
+}
+
+bool is_number(const char* test_string)
+{
+    char* p;
+    strtod(test_string, &p);
+    return *p == 0;
+}
+
+std::string get_username_from_key(std::string &key)
+{
+  std::ifstream codefin(TCOIN_CODEZ_PATH);
+  char code1[513], code2[513], code3[513];
+  codefin >> code1;
+  codefin >> code2;
+  codefin >> code3;
+  codefin.close();
+  const static std::string all_usernames_dot_txt = exec2((std::string(TCOIN_BIN_PATH_W_SPACE) + std::string("pcoin_list")).c_str(), std::string(code3));
+
+  std::istringstream iss(all_usernames_dot_txt);
+
+  std::string word1, word2, program_name("n/a");
+  //first word is program username with .txt on the end, second word is key
+  while(iss >> word1)
+  {
+    char *program_key_path = new char[strlen(word1.c_str()) + sizeof(PCOIN_KEY_PATH_W_SLASH)]; //sizeof counts NULL char at the end too
+    std::strcpy(program_key_path, PCOIN_KEY_PATH_W_SLASH);
+    std::strcat(program_key_path, word1.c_str());
+
+    std::ifstream fin(program_key_path);
+
+    fin >> word2;
+
+    if(!strctcmp(word2.c_str(), key.c_str()))
+    {
+      fin.close();
+      delete[] program_key_path;
+      program_name = word1.substr(0, word1.size()-4); //removing .txt from the username returned
+    }
+    else
+    {
+      fin.close();
+      delete[] program_key_path;
+    }
+  }
+  return program_name;
+}
+
+long long int get_internal_balance(const char* username)
+{
+  //sometimes, it just helps to double-check things
+  //this makes the security of this function decoupled
+  //from the 'deny access' mechanism in the "main"
+  //function when an incorrect key is entered
+  if(program_exists(get_username().c_str()) && username_exists(username))
+  {
+    std::string internal_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/") + std::string(username) + std::string(".txt");
+    //create internal balance file if none exists
+    {
+      std::ifstream fin(internal_path.c_str());
+      if(!fin || file_is_empty(fin))
+      {
+        fin.close();
+        std::ofstream fout(internal_path.c_str(), std::fstream::trunc);
+        fout << "0\n";
+        fout.close();
+      }
+      else
+        fin.close();
+      chmod(internal_path.c_str(), CHMOD_PERMISSIONS);
+    }
+
+    std::string internal_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/") + std::string(username);
+    return get_file_value(internal_username.c_str());
+  }
+  return ERR_IN_GET_INTERNAL_BALANCE;
+}
+
+long long int get_internal_total_owed()
+{
+  if(program_exists(get_username().c_str()))
+  {
+    std::string internal_total_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/_TOTAL.txt");
+    //create internal total file if none exists
+    {
+      std::ifstream fin(internal_total_path.c_str());
+      if(!fin || file_is_empty(fin))
+      {
+        fin.close();
+        std::ofstream fout(internal_total_path.c_str(), std::fstream::trunc);
+        fout << "0\n";
+        fout.close();
+      }
+      else
+        fin.close();
+      chmod(internal_total_path.c_str(), CHMOD_PERMISSIONS);
+    }
+
+    std::string internal_total_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/_TOTAL");
+    return get_file_value(internal_total_username.c_str());
+  }
+  return ERR_IN_GET_INTERNAL_TOTAL_OWED_SELF_PROGRAM_DOESNT_EXIST;
+}
+
+int add_internal_balance(const char* username, const long long int value_to_add)
+{
+  if(!strcmp(get_username().c_str(), username))
+  {
+    return ERR_ADD_INTERNAL_BALANCE_ADD_TO_SELF;
+  }
+  if(program_exists(get_username().c_str()) && username_exists(username))
+  {
+    std::string random_string = std::string("rand");
+    std::string internal_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/") + std::string(username);
+    std::string temp_internal_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/") + std::string(username) + random_string;
+
+    long long int internal_total_owed = get_internal_total_owed();
+    if(internal_total_owed == ERR_IN_GET_INTERNAL_TOTAL_OWED_SELF_PROGRAM_DOESNT_EXIST)
+    {
+      std::cerr << "\nError in add_internal_balance()! get_internal_total_owed() failed!\n\n";
+      return ERR_IN_ADD_INTERNAL_BALANCE_GET_INTERNAL_TOTAL_OWED_FAILED;
+    }
+
+    if((value_to_add > 0) && (value_to_add > (base_amount + user_amount - internal_total_owed)))
+    {
+      return ERR_ADD_INTERNAL_BALANCE_VALUE_TO_ADD_UNFULFILLABLE_USING_OWN_CURRENT_FUNDS; //value_to_add is more than what the program can fulfil using its own current funds
+    }
+
+    std::string internal_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/") + std::string(username) + std::string(".txt");
+    std::string temp_internal_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/") + std::string(username) + random_string + std::string(".txt");
+    //create internal file if none exists
+    {
+      std::ifstream fin(internal_path.c_str());
+      std::ifstream fin2(temp_internal_path.c_str());
+      if((!fin || file_is_empty(fin)) && (!fin2))
+      {
+        fin.close();
+        std::ofstream fout(internal_path.c_str(), std::fstream::trunc);
+        fout << "0\n";
+        fout.close();
+      }
+      else
+        fin.close();
+      fin2.close();
+      chmod(internal_path.c_str(), CHMOD_PERMISSIONS);
+    }
+
+    int return_value;
+    int final_return_value = 0;
+    while(1)
+    {
+      if(!std::rename(internal_path.c_str(), temp_internal_path.c_str()))
+      {
+        return_value = add_file_value(temp_internal_username.c_str(), value_to_add, 0); //cannot make user's internal balance negative, so base_amount is 0
+
+        if(return_value) //if return value is non-zero
+        {
+          final_return_value = return_value; //we don't simply "return return_value" because we want files to get renamed back to their original filenames
+        }
+        else //return value is zero, i.e., add_file_value succeeded
+        //also need to update _total.txt
+        {
+          random_string = std::string("rand");
+          std::string internal_total_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/_TOTAL");
+          std::string temp_internal_total_username = std::string(PROG_ACT_W_SLASH) + get_username() + std::string("/_TOTAL") + random_string;
+          std::string internal_total_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/_TOTAL.txt");
+          std::string temp_internal_total_path = std::string(TCOIN_PROG_ACT_PATH) + get_username() + std::string("/_TOTAL") + random_string + std::string(".txt");
+
+          //create _total.txt file if none exists
+          {
+            std::ifstream fin(internal_total_path.c_str());
+            std::ifstream fin2(temp_internal_total_path.c_str());
+            if((!fin || file_is_empty(fin)) && (!fin2))
+            {
+              fin.close();
+              std::ofstream fout(internal_total_path.c_str(), std::fstream::trunc);
+              fout << "0\n";
+              fout.close();
+            }
+            else
+              fin.close();
+            fin2.close();
+            chmod(internal_total_path.c_str(), CHMOD_PERMISSIONS);
+          }
+
+          while(1)
+          {
+            if(!std::rename(internal_total_path.c_str(), temp_internal_total_path.c_str()))
+            {
+              return_value = add_file_value(temp_internal_total_username.c_str(), value_to_add, 0);
+              while(1)
+              {
+                if(!std::rename(temp_internal_total_path.c_str(), internal_total_path.c_str()))
+                  break;
+              }
+              break;
+            }
+          }
+          if(return_value) //if return value is non-zero
+            final_return_value = return_value; //we don't simply "return return_value" because we want files to get renamed back to their original filenames
+        }
+
+        while(1)
+        {
+          if(!std::rename(temp_internal_path.c_str(), internal_path.c_str()))
+            break;
+        }
+        break;
+      }
+    }
+    return final_return_value;
+  }
+  return ERR_ADD_INTERNAL_BALANCE_USERNAME_DOESNT_EXIST;
+}
+
+bool message_is_long(const char* test_string)
+{
+  for(int i=0; i < TCOIN_MSG_LENGTH_LIMIT+1; ++i)
+    if(test_string[i] == '\0')
+    {
+      return false; //message is shorter than TCOIN_MSG_LENGTH_LIMIT characters
+    }
+  return true; //message is longer than TCOIN_MSG_LENGTH_LIMIT characters
+}
+
+int main(int argc, char *argv[])
+{
+  if(argc > 1 && (!strcmp(argv[1], "--help") || !strcmp(argv[1], "help") || !strcmp(argv[1], "-h")))
+  {
+    help();
+    return 0;
+  }
+
+  {
+    std::string key;
+    std::string program_username;
+    std::getline(std::cin, key);
+
+    if(!key.compare(""))
+    {
+      std::cout << "\nSorry, you incorrectly specified an empty key.\n\n";
+      return ERR_KEY_EMPTY;
+    }
+
+    program_username.assign(get_username_from_key(key));
+
+    if(!program_username.compare("n/a"))
+    {
+      std::cout << "\nSorry, the key you specified is not in use.\n\n";
+      return ERR_KEY_NOT_IN_USE;
+    }
+    set_username(program_username);
+  }
+
+  base_amount = 0;
+  long long int unaltered_base_amount = base_amount;
+  user_amount = 0;
+  krowbar_amount[0] = krowbar_amount[1] = 0;
+  minercoin_amount[0] = minercoin_amount[1] = 0;
+
+  #ifndef KROWBAR_OFF
+  //adding tildebot scores from krowbar to base amount
+  {
+    std::string line;
+    const std::string username = get_username();
+    const int username_length = username.length();
+
+    std::string score_file_path;
+
+    for(int j=0; j<2; ++j)
+    {
+      if(j == 0)
+        score_file_path.assign(KROWBAR_SCORE_PATH);
+      else if(j == 1)
+        score_file_path.assign(JU_SCORE_PATH);
+
+      std::ifstream fin(score_file_path);
+
+      while(std::getline(fin, line))
+      {
+        char* line_c_string = new char[line.length()+1];
+        std::strcpy(line_c_string, line.c_str());
+
+        const int irc_username_length = username_length > USERNAME_LENGTH_LIMIT ? USERNAME_LENGTH_LIMIT : username_length;
+
+        if(!strncasecmp(username.c_str(), line_c_string, irc_username_length)) //username starts with capital letter, but name in database does not
+        {
+          char number_of_tildes[21];
+          number_of_tildes[0] = '0'; //just in case the loop below doesn't detect any digits
+          number_of_tildes[1] = '\0';
+
+          for(int i=0; i < 20; ++i)
+          {
+            if(std::isdigit(line_c_string[irc_username_length+3+i])
+            || line_c_string[irc_username_length+3+i] == '-'
+            || line_c_string[irc_username_length+3+i] == '.')
+              number_of_tildes[i] = line_c_string[irc_username_length+3+i];
+            else
+            {
+              number_of_tildes[i] = '\0'; //manually terminating the string
+              break;
+            }
+          }
+          number_of_tildes[20] = '\0'; //incase the number overflows 20 characters
+          krowbar_amount[j] += strtol100(number_of_tildes);
+          base_amount += krowbar_amount[j];
+          //multiplied by 100 inside strtol100() to convert tildecoins to centitildecoins, which
+          //is the unit used throughout the program (and converted appropriately when displayed)
+        }
+        delete[] line_c_string;
+      }
+    }
+  }
+  #endif
+
+  #if DEBUG
+    std::string debug_string("");
+  #endif
+
+  #ifndef MINERCOIN_OFF
+  {
+    std::string command_to_exec, minercoin_cmd_pre_username, number_of_tildes, username(get_username());
+    username.at(0) = username.at(0)+'a'-'A';
+    const std::string minercoin_cmd_post_username(MINERCOIN_CMD_POST_USERNAME), lowercase_username(username);
+    //adding minercoin scores from minerobber to base amount (from "~username" and "username", both, in minerbot)
+    #if DEBUG
+      debug_string += lowercase_username;
+    #endif
+    for(int i=0; i<2; ++i)
+    {
+      if(i == 0)
+        minercoin_cmd_pre_username.assign(MINERCOIN_CMD_PRE_USERNAME);
+      else if(i == 1)
+        minercoin_cmd_pre_username.assign(MINERCOIN_CMD_PRE_USERNAME2);
+
+      command_to_exec = minercoin_cmd_pre_username + lowercase_username + minercoin_cmd_post_username;
+      number_of_tildes = exec(command_to_exec.c_str());
+      number_of_tildes.pop_back();
+      //to get rid of the newline at the end
+      if(is_number(number_of_tildes.c_str()))
+      {
+        minercoin_amount[i] += strtol100(number_of_tildes.c_str());
+        base_amount += minercoin_amount[i];
+      }
+      //multiplied by 100 to convert tildecoins to centitildecoins, which
+      //is the unit used throughout the program (and converted appropriately when displayed)
+    }
+  }
+  #endif
+
+  user_amount = get_file_value(get_username().c_str());
+
+  srand((long int)(std::time(NULL)) + strtol_fast(exec(BIN_ECHO_CMD).c_str()));
+
+  long long int total_amount = base_amount + user_amount;
+
+  if(argc < 2)
+  {
+    std::cout << "\nSorry, `" << PCOIN_BIN_PATH << "` doesn't work. Please use `" << PCOIN_BIN_PATH_W_SPACE << "-m` for messages or `" << PCOIN_BIN_PATH_W_SPACE << "-b` to check your balance. `" << PCOIN_BIN_PATH_W_SPACE << "--help` prints the help text.\n\n";
+    return ERR_NO_ARGS;
+  }
+  else if(!strcmp(argv[1], "breakdown") || !strcmp(argv[1], "-bd"))
+  {
+    std::cout << "total,";
+    cout_formatted_amount(total_amount, ";", ";");
+    show_breakdown(unaltered_base_amount, "baseamount", user_amount, "transfers", krowbar_amount[0], "tildegame", krowbar_amount[1], "jugame", minercoin_amount[0]+minercoin_amount[1], "minercoingame");
+  }
+  #if DEBUG
+    else if(!strcmp(argv[1], "debug_string"))
+    {
+      std::cout << debug_string;
+    }
+  #endif
+  else if(!strcmp(argv[1], "messages") || !strcmp(argv[1], "-m"))
+  {
+    double number_of_messages = 0.0;
+    bool number_of_messages_is_specified = argc > 2 && is_number(argv[2]); //number of messages specified
+    if(number_of_messages_is_specified)
+      number_of_messages = std::strtod(argv[2], NULL);
+    if(number_of_messages >= 1.0) //number of messages specified is a valid number
+      show_messages_tail(get_username().c_str(), (long long int)(number_of_messages));
+    else //show all messages
+      show_messages(get_username().c_str());
+  }
+  else if(!strcmp(argv[1], "messages_tsv") || !strcmp(argv[1], "-mtsv"))
+  {
+    double number_of_messages = 0.0;
+    bool number_of_messages_is_specified = argc > 2 && is_number(argv[2]); //number of messages specified
+    if(number_of_messages_is_specified)
+      number_of_messages = std::strtod(argv[2], NULL);
+    if(number_of_messages >= 1.0) //number of messages specified is a valid number
+      show_tsv_messages_tail(get_username().c_str(), (long long int)(number_of_messages));
+    else //show all messages
+      show_tsv_messages(get_username().c_str());
+  }
+  else if(!strcmp(argv[1], "balance") || !strcmp(argv[1], "-b"))
+    cout_formatted_amount(total_amount, "\n");
+  else if(!strcmp(argv[1], "total_owed") || !strcmp(argv[1], "-to"))
+  {
+    long long int total_owed = get_internal_total_owed();
+    if(total_owed == ERR_IN_GET_INTERNAL_TOTAL_OWED_SELF_PROGRAM_DOESNT_EXIST)
+    {
+      std::cerr << "\nError in main()! get_internal_total_owed() failed!\n\n";
+      return ERR_IN_MAIN_GET_INTERNAL_TOTAL_OWED_FAILED;
+    }
+    cout_formatted_amount(total_owed, "\n");
+  }
+  else if(!strcmp(argv[1], "internal_balance") || !strcmp(argv[1], "-ib"))
+  {
+    if(argc == 3) //second argument (the one right after "-ib") is the username
+    {
+      long long int internal_balance = get_internal_balance(argv[2]);
+      if(internal_balance == ERR_IN_GET_INTERNAL_BALANCE) //username check doesn't pass
+      {
+        std::cout << "\nSorry, no user with the username `" << argv[2] << "` was found.\n\n";
+        return ERR_INTERNAL_BALANCE_USERNAME_NOT_FOUND;
+      }
+      cout_formatted_amount(internal_balance, "\n");
+    }
+    else if(argc == 2) //no username supplied (too few arguments supplied)
+    {
+      std::cout << "\nSorry, too few command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "internal_balance <username>`.\n\n";
+      return ERR_INTERNAL_BALANCE_NO_USERNAME_SUPPLIED;
+    }
+    else if(argc > 3) //too many arguments supplied
+    {
+      std::cout << "\nSorry, too many command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "internal_balance <username>`.\n\n";
+      return ERR_INTERNAL_BALANCE_TOO_MANY_ARGS;
+    }
+  }
+  else if(!strcmp(argv[1], "add_internal_balance") || !strcmp(argv[1], "-aib"))
+  {
+    if(argc < 4)
+    {
+      std::cout << "\nSorry, too few command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "add_internal_balance <username> <amount>`.\n\n";
+      return ERR_ADD_INTERNAL_BALANCE_TOO_FEW_ARGS;
+    }
+    else if(argc > 4)
+    {
+      std::cout << "\nSorry, too many command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "add_internal_balance <username> <amount>`.\n\n";
+      return ERR_ADD_INTERNAL_BALANCE_TOO_MANY_ARGS;
+    }
+    // number of arguments is exactly 3
+    {
+      int return_value = ERR_IN_ADD_INTERNAL_BALANCE_GET_INTERNAL_TOTAL_OWED_FAILED, return_value2 = ERR_IN_ADD_INTERNAL_BALANCE_GET_INTERNAL_TOTAL_OWED_FAILED;
+      if(is_number(argv[3]))
+        return_value = add_internal_balance(argv[2], strtol100(argv[3]));
+      else
+        return_value2 = add_internal_balance(argv[3], strtol100(argv[2]));
+
+      if(return_value == ERR_ADD_INTERNAL_BALANCE_ADD_TO_SELF || return_value2 == ERR_ADD_INTERNAL_BALANCE_ADD_TO_SELF) //cannot add to self internal balance
+      {
+        std::cout << "\nSorry, you cannot add to your own internal balance.\n\n";
+        return ERR_ADD_INTERNAL_BALANCE_ADD_TO_SELF;
+      }
+      if(return_value == ERR_ADD_INTERNAL_BALANCE_VALUE_TO_ADD_UNFULFILLABLE_USING_OWN_CURRENT_FUNDS || return_value2 == ERR_ADD_INTERNAL_BALANCE_VALUE_TO_ADD_UNFULFILLABLE_USING_OWN_CURRENT_FUNDS) //value_to_add was too large
+      {
+        std::cout << "\nSorry, the amount was larger than what the program's current unowed balance could cover.\n\n";
+        return ERR_IN_MAIN_ADD_INTERNAL_BALANCE_AMOUNT_LARGER_THAN_COVERABLE_BY_UNOWED_BALANCE;
+      }
+      if(return_value == ERR_ADD_FILE_VALUE_INSUFFICIENT_FUNDS) //value_to_add was too negative
+      {
+        std::cout << "\nSorry, the amount was more negative than what `" << argv[2] << "` could cover.\n\n";
+        return ERR_IN_MAIN_ADD_INTERNAL_BALANCE_AMOUNT_MAKING_USER_INTERNAL_BALANCE_NEGATIVE;
+      }
+      if(return_value2 == ERR_ADD_FILE_VALUE_INSUFFICIENT_FUNDS) //value_to_add was too negative
+      {
+        std::cout << "\nSorry, the amount was more negative than what `" << argv[3] << "` could cover.\n\n";
+        return ERR_IN_MAIN_ADD_INTERNAL_BALANCE_AMOUNT_MAKING_USER_INTERNAL_BALANCE_NEGATIVE;
+      }
+      if(return_value == ERR_ADD_INTERNAL_BALANCE_USERNAME_DOESNT_EXIST) //username check doesn't pass
+      {
+        std::cout << "\nSorry, no user with the username `" << argv[2] << "` was found.\n\n";
+        return ERR_IN_MAIN_ADD_INTERNAL_BALANCE_NO_SUCH_USERNAME_FOUND;
+      }
+      if(return_value2 == ERR_ADD_INTERNAL_BALANCE_USERNAME_DOESNT_EXIST) //username check doesn't pass
+      {
+        std::cout << "\nSorry, no user with the username `" << argv[3] << "` was found.\n\n";
+        return ERR_IN_MAIN_ADD_INTERNAL_BALANCE_NO_SUCH_USERNAME_FOUND;
+      }
+    }
+  }
+  else if(!strcmp(argv[1], "send") || !strcmp(argv[1], "-s"))
+  {
+    if(argc == 5)
+    {
+      if(!strcmp(argv[2], "-s"))
+      {
+        int return_value;
+        long long int amount = 0;
+        char *receiver = NULL;
+
+        if(is_number(argv[3]))
+        {
+          amount = strtol100(argv[3]);
+          receiver = argv[4];
+        }
+        else
+        {
+          amount = strtol100(argv[4]);
+          receiver = argv[3];
+        }
+        return_value = send(get_username().c_str(), receiver, amount, base_amount, "silent");
+        if(!return_value) //send was successful
+          send_message(get_username().c_str(), receiver, "", amount, "silent");
+      }
+      else //argument count is 5 because a custom message was included
+      {
+        int return_value;
+        long long int amount = 0;
+        char* receiver = NULL;
+
+        return_value = message_is_long(argv[4]);
+        if(return_value) //message is too long
+        {
+          std::cout << "\nSorry, the message was longer than " << TCOIN_MSG_LENGTH_LIMIT << " characters. Please keep messages at or below this limit.\n\n";
+          return ERR_MAIN_MSG_TOO_LONG;
+        }
+        if(is_number(argv[2]))
+        {
+          amount = strtol100(argv[2]);
+          receiver = argv[3];
+        }
+        else
+        {
+          amount = strtol100(argv[3]);
+          receiver = argv[2];
+        }
+        return_value = send(get_username().c_str(), receiver, amount, base_amount, "verbose");
+        if(!return_value) //send was successful
+          send_message(get_username().c_str(), receiver, argv[4], amount, "verbose");
+      }
+    }
+    else if(argc == 6)
+    {
+      if(!strcmp(argv[2], "-s"))
+      { //argument count is 6 because of silent send with custom message included
+        int return_value;
+        long long int amount = 0;
+        char *receiver = NULL;
+
+        return_value = message_is_long(argv[5]);
+        if(return_value) //message is too long
+        {
+          std::cout << "\nSorry, the message was longer than " << TCOIN_MSG_LENGTH_LIMIT << " characters. Please keep messages at or below this limit.\n\n";
+          return ERR_MAIN_MSG_TOO_LONG;
+        }
+
+        if(is_number(argv[3]))
+        {
+          amount = strtol100(argv[3]);
+          receiver = argv[4];
+        }
+        else
+        {
+          amount = strtol100(argv[4]);
+          receiver = argv[3];
+        }
+        return_value = send(get_username().c_str(), receiver, amount, base_amount, "silent");
+        if(!return_value) //send was successful
+          send_message(get_username().c_str(), receiver, argv[5], amount, "silent");
+      }
+      else
+      {
+        //too many command-line arguments were passed (6 args) (probably a message was intended)
+        std::cout << "\nSorry, too many command-line arguments were passed. The correct format is `tcoin send <username> <amount> \"<message>\"`.\n\n";
+        return ERR_MAIN_SEND_TOO_MANY_ARGS_MSG;
+      }
+    }
+    else if(argc < 4)
+    {
+      std::cout << "\nSorry, too few command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "send <username> <amount>`.\n\n";
+      return ERR_MAIN_SEND_TOO_FEW_ARGS;
+    }
+    else if(argc > 4)
+    {
+      std::cout << "\nSorry, too many command-line arguments were passed. The correct format is `" << PCOIN_BIN_PATH_W_SPACE << "send <username> <amount>`.\n\n";
+      return ERR_MAIN_SEND_TOO_MANY_ARGS;
+    }
+    else
+    {
+      int return_value;
+      long long int amount = 0;
+      char* receiver = NULL;
+
+      if(is_number(argv[2]))
+      {
+        amount = strtol100(argv[2]);
+        receiver = argv[3];
+      }
+      else
+      {
+        amount = strtol100(argv[3]);
+        receiver = argv[2];
+      }
+      return_value = send(get_username().c_str(), receiver, amount, base_amount, "verbose");
+      if(!return_value) //send was successful
+        send_message(get_username().c_str(), receiver, "", amount, "verbose");
+    }
+  }
+  else if(!strcmp(argv[1], "silentsend") || !strcmp(argv[1], "-ss"))
+  {
+    if(argc==4)
+    {
+      int return_value;
+      long long int amount = 0;
+      char* receiver = NULL;
+
+      if(is_number(argv[2]))
+      {
+        amount = strtol100(argv[2]);
+        receiver = argv[3];
+      }
+      else
+      {
+        amount = strtol100(argv[3]);
+        receiver = argv[2];
+      }
+      return_value = send(get_username().c_str(), receiver, amount, base_amount, "silent");
+      if(!return_value) //send was successful
+        send_message(get_username().c_str(), receiver, "", amount, "silent");
+    }
+    if(argc==5) //custom message included
+    {
+      int return_value;
+      long long int amount = 0;
+      char* receiver = NULL;
+
+      return_value = message_is_long(argv[4]);
+      if(return_value) //message is too long
+      {
+        std::cout << "\nSorry, the message was longer than " << TCOIN_MSG_LENGTH_LIMIT << " characters. Please keep messages at or below this limit.\n\n";
+        return ERR_MAIN_MSG_TOO_LONG;
+      }
+      if(is_number(argv[2]))
+      {
+        amount = strtol100(argv[2]);
+        receiver = argv[3];
+      }
+      else
+      {
+        amount = strtol100(argv[3]);
+        receiver = argv[2];
+      }
+      return_value = send(get_username().c_str(), receiver, amount, base_amount, "silent");
+      if(!return_value) //send was successful
+        send_message(get_username().c_str(), receiver, argv[4], amount, "silent");
+    }
+    else
+      return ERR_SILENTSEND;
+  }
+  else if(!strcmp(argv[1], "refresh_key") || !strcmp(argv[1], "-rk"))
+  {
+    std::string new_key;
+
+    new_key.assign(refresh_pcoin_key());
+
+    if(!new_key.compare("n/a") || new_key.length() != 64)
+    {
+      std::cout << "\nSorry, key was not refreshed.\n\n"; //make sure this is less than 64 characters
+      return ERR_PCOIN_KEY_REFRESH_FAILED;
+    }
+    else
+      std::cout << new_key << "\n";
+  }
+  else if(!strcmp(argv[1], "name") || !strcmp(argv[1], "-n"))
+  {
+    std::cout << get_username() << "\n";
+  }
+  else
+  {
+    std::cout << "\nSorry, an unknown command-line argument was received. `" << PCOIN_BIN_PATH_W_SPACE << "help` will print the help text.\n\n";
+    return ERR_UNKNOWN_ARG;
+  }
+
+  return 0;
+}