cosmopolitan/libc/stdio/getdelim.c

65 lines
3.1 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/errno.h"
#include "libc/mem/mem.h"
#include "libc/stdio/internal.h"
#include "libc/stdio/stdio.h"
#define GETDELIM_MAX 65536
/**
* Reads string from stream.
*
* @param line is the caller's buffer (in/out) which is extended
* automatically. *line may be NULL but only if *n is 0;
* NUL-termination is guaranteed FTMP
* @param n is the capacity of line (in/out)
* @param delim is the stop char (and NUL is implicitly too)
* @return number of bytes read, including delim, excluding NUL, or -1
* w/ errno on EOF or error; see ferror() and feof()
* @note this function can't punt EINTR to caller
* @see getline(), gettok_r()
*/
ssize_t getdelim(char **line, size_t *n, int delim, FILE *f) {
STATIC_YOINK("realloc");
assert((*line && *n) || (!*line && !*n));
ssize_t rc = -1;
size_t i = 0;
int c;
for (;;) {
if ((c = getc(f)) == -1) {
if (ferror(f) == EINTR) continue;
if (feof(f) && i) rc = i;
break;
}
if (i + 2 >= *n && !__grow(line, n, 1, 0)) {
__fseterrno(f);
break;
}
if (((*line)[i++] = c) == delim) {
rc = i;
break;
}
}
if (*line && i < *n) (*line)[i] = '\0';
return rc;
}