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#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
/* errors */
void perr(const char *s) {
fprintf(stderr, "%s\n", s);
}
/* misc */
int running;
int quit(const char *_) {
puts("goodbye!");
running = 0;
return 0;
}
/* documents */
#define TXT_BUF_SIZE (1024 * 1024)
struct {
char buf[TXT_BUF_SIZE];
size_t n;
} text;
struct doc {
struct doc *prev, *next;
struct {
size_t ofs, len, idx;
} txt;
};
#define DOC_MAX 32
struct doc docv[DOC_MAX];
size_t docn = 0, doci = 0;
int doc_new(void) {
if (doci < docn) {
text.n = docv[doci].txt.ofs;
docn = doci;
}
if (docn >= DOC_MAX) return -1;
memset(&docv[docn], 0, sizeof(struct doc));
docv[docn].txt.ofs = text.n;
docv[docn].txt.idx = text.n;
doci = docn++;
return 0;
}
int doc_add(char *buf, size_t n) {
if (text.n + n > TXT_BUF_SIZE) {
return -1;
}
memcpy(&text.buf[text.n], buf, n);
text.n += n;
return 0;
}
void doc_prev(void) {
if (doci > 0) doci--;
}
void doc_next(void) {
if (doci < docn) doci++;
}
/* pagination */
size_t pg_lines() {
return 24;
}
int pg_down(const char *_) {
if (doci >= docn) return -1;
size_t lines = pg_lines();
size_t i = docv[doci].txt.idx;
size_t end = docv[doci].txt.ofs + docv[doci].txt.len;
while (lines > 0 && i < end) {
putchar(text.buf[i]);
if (text.buf[i] == '\n') lines--;
i++;
}
return 0;
}
int pg_up(const char *_) {
if (doci >= docn) return -1;
size_t lines = pg_lines() << 1;
size_t i = docv[doci].txt.idx;
while (lines > 0 && i > 0) {
putchar(text.buf[i]);
if (text.buf[i] == '\n') lines--;
i--;
}
pg_down(_);
return 0;
}
/* navigation */
#define HOST_MAX 255
#define PATH_MAX 255
enum doc_type {
TYPE_GOPHERDOC,
TYPE_GEMTEXT,
TYPE_PLAIN,
TYPE_UNKNOWN
};
enum protocol {
PROT_FILE,
PROT_GOPHER,
PROT_GEMINI,
PROT_UNKNOWN,
};
struct addr {
char host[HOST_MAX];
char path[PATH_MAX];
size_t host_len, path_len;
enum protocol prot;
enum doc_type type;
};
int url_to_addr(const char *url, struct addr *adr) {
char *colon = strchr(url, ':');
adr->prot = PROT_UNKNOWN;
if (colon) {
}
return -1;
}
int nav_to(const char *url) {
return 0;
}
int nav_link_nr(unsigned long link_nr) {
return 0;
}
/* commands */
struct cmd {
char ch;
int (*fn)(const char *);
};
struct cmd cmd_tbl[] = {
{ 'g', nav_to },
{ '\n', pg_down },
{ '\b', pg_up },
{ 'q', quit }
};
/* cmd is mutated when trimming strings */
void cmd_do(char *cmd) {
if (isdigit(*cmd)) {
errno = 0;
unsigned long n = strtoul(cmd, NULL, 10);
if (errno) {
perr("invalid link number");
} else if (nav_link_nr(n)) {
perr("navigation failure");
}
} else {
for (size_t i = 0; i < sizeof cmd_tbl / sizeof(struct cmd); i++) {
if (cmd_tbl[i].ch == *cmd) {
while (isspace(*++cmd));
for (int j = strlen(cmd) - 1; j > 0 && isspace(cmd[j]); j--) {
cmd[j] = 0;
}
if (cmd_tbl[i].fn(cmd)) {
perr("failed");
}
goto found;
}
}
perr("?");
found: ;
}
}
int cmd_get(char *buf, size_t n) {
fputs("* ", stdout);
return !!fgets(buf, n, stdin);
}
int main(void) {
char cmd_buf[1024];
running = 1;
while (running && cmd_get(cmd_buf, sizeof cmd_buf)) {
cmd_do(cmd_buf);
}
return 0;
}
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