glibc/grp/fgetgrent_r.c

108 lines
2.9 KiB
C

/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <errno.h>
#include <grp.h>
#include <stdio.h>
#include <libio/iolibio.h>
#define flockfile(s) _IO_flockfile (s)
#define funlockfile(s) _IO_funlockfile (s)
/* Define a line parsing function using the common code
used in the nss_files module. */
#define STRUCTURE group
#define ENTNAME grent
struct grent_data {};
#define TRAILING_LIST_MEMBER gr_mem
#define TRAILING_LIST_SEPARATOR_P(c) ((c) == ',')
#include <nss/nss_files/files-parse.c>
LINE_PARSER
(,
STRING_FIELD (result->gr_name, ISCOLON, 0);
if (line[0] == '\0'
&& (result->gr_name[0] == '+' || result->gr_name[0] == '-'))
{
result->gr_passwd = NULL;
result->gr_gid = 0;
}
else
{
STRING_FIELD (result->gr_passwd, ISCOLON, 0);
if (result->gr_name[0] == '+' || result->gr_name[0] == '-')
INT_FIELD_MAYBE_NULL (result->gr_gid, ISCOLON, 0, 10, , 0)
else
INT_FIELD (result->gr_gid, ISCOLON, 0, 10,)
}
)
/* Read one entry from the given stream. */
int
__fgetgrent_r (FILE *stream, struct group *resbuf, char *buffer, size_t buflen,
struct group **result)
{
char *p;
int parse_result;
flockfile (stream);
do
{
buffer[buflen - 1] = '\xff';
p = fgets_unlocked (buffer, buflen, stream);
if (__builtin_expect (p == NULL, 0) && feof_unlocked (stream))
{
funlockfile (stream);
*result = NULL;
__set_errno (ENOENT);
return errno;
}
if (__builtin_expect (p == NULL, 0) || buffer[buflen - 1] != '\xff')
{
funlockfile (stream);
*result = NULL;
__set_errno (ERANGE);
return errno;
}
/* Skip leading blanks. */
while (isspace (*p))
++p;
} while (*p == '\0' || *p == '#' /* Ignore empty and comment lines. */
/* Parse the line. If it is invalid, loop to
get the next line of the file to parse. */
|| ! (parse_result = parse_line (p, resbuf,
(void *) buffer, buflen,
&errno)));
funlockfile (stream);
if (__builtin_expect (parse_result, 0) == -1)
{
/* The parser ran out of space. */
*result = NULL;
return errno;
}
*result = resbuf;
return 0;
}
weak_alias (__fgetgrent_r, fgetgrent_r)