File: fgetspent.c

package info (click to toggle)
glibc 2.24-11+deb9u4
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 225,852 kB
  • sloc: ansic: 996,505; asm: 261,827; sh: 10,484; makefile: 9,856; cpp: 4,169; python: 3,971; perl: 2,254; awk: 1,753; pascal: 1,521; yacc: 291; sed: 80
file content (87 lines) | stat: -rw-r--r-- 2,293 bytes parent folder | download | duplicates (5)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
/* Copyright (C) 1996-2016 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
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <libc-lock.h>
#include <shadow.h>
#include <stdio.h>
#include <stdlib.h>


/* A reasonable size for a buffer to start with.  */
#define BUFLEN_SPWD 1024

/* We need to protect the dynamic buffer handling.  */
__libc_lock_define_initialized (static, lock);

libc_freeres_ptr (static char *buffer);

/* Read one shadow entry from the given stream.  */
struct spwd *
fgetspent (FILE *stream)
{
  static size_t buffer_size;
  static struct spwd resbuf;
  fpos_t pos;
  struct spwd *result;
  int save;

  if (fgetpos (stream, &pos) != 0)
    return NULL;

  /* Get lock.  */
  __libc_lock_lock (lock);

  /* Allocate buffer if not yet available.  */
  if (buffer == NULL)
    {
      buffer_size = BUFLEN_SPWD;
      buffer = malloc (buffer_size);
    }

  while (buffer != NULL
	 && (__fgetspent_r (stream, &resbuf, buffer, buffer_size, &result)
	     == ERANGE))
    {
      char *new_buf;
      buffer_size += BUFLEN_SPWD;
      new_buf = realloc (buffer, buffer_size);
      if (new_buf == NULL)
	{
	  /* We are out of memory.  Free the current buffer so that the
	     process gets a chance for a normal termination.  */
	  save = errno;
	  free (buffer);
	  __set_errno (save);
	}
      buffer = new_buf;

      /* Reset the stream.  */
      if (fsetpos (stream, &pos) != 0)
	buffer = NULL;
    }

  if (buffer == NULL)
    result = NULL;

  /* Release lock.  Preserve error value.  */
  save = errno;
  __libc_lock_unlock (lock);
  __set_errno (save);

  return result;
}