mips: FIx clone3 implementation (BZ 31325)
[glibc.git] / nss / fgetpwent.c
blob5a1fd9d696b6cd3f9b846f24cb289705e0cc66c6
1 /* Copyright (C) 1991-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
18 #include <errno.h>
19 #include <libc-lock.h>
20 #include <pwd.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <set-freeres.h>
26 /* We need to protect the dynamic buffer handling. */
27 __libc_lock_define_initialized (static, lock);
29 static char *buffer;
31 /* Read one entry from the given stream. */
32 struct passwd *
33 fgetpwent (FILE *stream)
35 static size_t buffer_size;
36 static struct passwd resbuf;
37 fpos_t pos;
38 struct passwd *result;
39 int save;
41 if (fgetpos (stream, &pos) != 0)
42 return NULL;
44 /* Get lock. */
45 __libc_lock_lock (lock);
47 /* Allocate buffer if not yet available. */
48 if (buffer == NULL)
50 buffer_size = NSS_BUFLEN_PASSWD;
51 buffer = malloc (buffer_size);
54 while (buffer != NULL
55 && (__fgetpwent_r (stream, &resbuf, buffer, buffer_size, &result)
56 == ERANGE))
58 char *new_buf;
59 buffer_size += NSS_BUFLEN_PASSWD;
60 new_buf = realloc (buffer, buffer_size);
61 if (new_buf == NULL)
63 /* We are out of memory. Free the current buffer so that the
64 process gets a chance for a normal termination. */
65 save = errno;
66 free (buffer);
67 __set_errno (save);
69 buffer = new_buf;
71 /* Reset the stream. */
72 if (fsetpos (stream, &pos) != 0)
73 buffer = NULL;
76 if (buffer == NULL)
77 result = NULL;
79 /* Release lock. Preserve error value. */
80 save = errno;
81 __libc_lock_unlock (lock);
82 __set_errno (save);
84 return result;
87 weak_alias (buffer, __libc_fgetpwent_freemem_ptr)