Files
heimdal/lib/roken/getdelim.c
Nicolas Williams 5fa7d6edd8 roken: Add getdelim()/getline()
Ported from lib/libedit's.
2026-01-18 16:08:39 -06:00

121 lines
3.4 KiB
C

/*
* Copyright (c) 2011 James E. Ingram
* Copyright (c) 2024 Heimdal Project
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*
* Implementation of the getdelim() function from POSIX 2008.
*
* getdelim() reads from a stream until a specified delimiter is encountered.
*
* See: http://pubs.opengroup.org/onlinepubs/9699919799/functions/getdelim.html
*
* NOTE: It is always the caller's responsibility to free the line buffer, even
* when an error occurs.
*/
#include <config.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include "roken.h"
#ifndef SSIZE_MAX
#define SSIZE_MAX ((ssize_t)(SIZE_MAX / 2))
#endif
#define GETDELIM_MINLEN 16 /* minimum line buffer size */
#define GETDELIM_MAXLEN 65536 /* maximum line buffer size */
#ifndef HAVE_GETDELIM
ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL
getdelim(char **lineptr, size_t *n, int delimiter, FILE *stream)
{
char *buf, *pos;
int c;
ssize_t bytes;
size_t read;
if (lineptr == NULL || n == NULL) {
errno = EINVAL;
return -1;
}
if (stream == NULL) {
errno = EBADF;
return -1;
}
/* read characters until delimiter is found, end of file is reached, or an
error occurs. */
read = 0;
bytes = 0;
buf = *lineptr;
pos = buf;
while ((c = getc(stream)) != EOF) {
if (bytes + 1 >= SSIZE_MAX) {
errno = ERANGE;
return -1;
}
read++;
bytes++;
if (*n < GETDELIM_MINLEN || read >= *n - 2 /* 1 for the delimiter, one for a NUL */) {
size_t newsz = *n + (GETDELIM_MINLEN + ((*n) >> 1));
/*
* Better than an overflow check like (size_t)SSIZE_MAX - newsz <
* newsz. Obviously we assume larger than 16-bit architectures.
*/
if (newsz > GETDELIM_MAXLEN) {
errno = ERANGE;
return -1;
}
buf = realloc(*lineptr, newsz);
if (buf == NULL) {
/* ENOMEM */
return -1;
}
*n = newsz;
pos = buf + bytes - 1;
*lineptr = buf;
}
*pos++ = (char)c;
if (c == delimiter) {
*pos = '\0';
return bytes;
}
}
if (ferror(stream) || (feof(stream) && (bytes == 0))) {
/* EOF, or an error from getc(). */
return -1;
}
*pos = '\0';
return bytes;
}
#endif /* !HAVE_GETDELIM */