summaryrefslogtreecommitdiff
path: root/lib/fgetpwent.c
blob: 885cc5124b93c3810dacd86ef4e187ebeafe1fc1 (plain)
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
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.

   GNU Mailutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Library Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   GNU Mailutils 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 Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with GNU Mailutils; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>
#include <pwd.h>
#include <string.h>
#include <stdlib.h>

/*
  Written by Alain Magloire.
  Simple replacement for fgetpwent(), it is not :
  - thread safe;
  - static buffer was not use since it will limit the size
    of the entry.  But rather memory is allocated and __never__
    release.  The memory will grow if need be.
  - no support for shadow
  - no support for NIS(+)
*/

static char *buffer;
static size_t buflen;
static struct passwd pw;


static char *
parse_line (char *s, char **p)
{
  if (*s)
    {
      char *sep = strchr (s, ':');
      if (sep)
	{
	  *sep++ = '\0';
	  *p = sep;
	}
      else
	*p = s + strlen (s);
    }
  else
    *p = s;
  return s;
}

static struct passwd *
getentry (char *s)
{
  char *p;
  pw.pw_name = parse_line (s, &p);
  s = p;
  pw.pw_passwd = parse_line (s, &p);
  s = p;
  pw.pw_uid = strtoul (parse_line (s, &p), NULL, 10);
  s = p;
  pw.pw_gid = strtoul (parse_line (s, &p), NULL, 10);
  s = p;
  pw.pw_gecos = parse_line (s, &p);
  s = p;
  pw.pw_dir = parse_line (s, &p);
  s = p;
  pw.pw_shell = parse_line (s, &p);
  return &pw;
}

struct passwd *
fgetpwent (FILE *fp)
{
  size_t pos = 0;
  int done = 0;
  struct passwd *pw = NULL;

  /* Allocate buffer if not yet available.  */
  /* This buffer will be never free().  */
  if (buffer == NULL)
    {
      buflen = 1024;
      buffer = malloc (buflen);
      if (buffer == NULL)
	return NULL;
    }

  do
    {
      if (fgets (buffer + pos, buflen, fp) != NULL)
	{
	  /* Need a full line.  */
	  if (buffer[strlen (buffer) - 1] == '\n')
	    {
	      /* reset marker position.  */
	      pos = 0;
	      /* Nuke trailing newline.  */
	      buffer[strlen (buffer) - 1] = '\0';

	      /* Skip comments.  */
	      if (buffer[0] != '#')
		{
		  done = 1;
		  pw = getentry (buffer);
		}
	    }
	  else
	    {
	      /* Line is too long reallocate the buffer.  */
	      char *tmp;
	      pos = strlen (buffer);
	      buflen *= 2;
	      tmp = realloc (buffer, buflen);
	      if (tmp)
		buffer = tmp;
	      else
		done = 1;
	    }
	}
      else
	done = 1;
    } while (!done);

  return pw;

}

#ifdef STANDALONE
int
main ()
{
  FILE *fp = fopen ("/etc/passwd", "r");
  if (fp)
    {
      struct passwd *pwd;
      while ((pwd = fgetpwent (fp)))
        {
          printf ("--------------------------------------\n");
          printf ("name %s\n", pwd->pw_name);
          printf ("passwd %s\n", pwd->pw_passwd);
          printf ("uid %d\n", pwd->pw_uid);
          printf ("gid %d\n", pwd->pw_gid);
          printf ("gecos %s\n", pwd->pw_gecos);
          printf ("dir %s\n", pwd->pw_dir);
          printf ("shell %s\n", pwd->pw_shell);
        }
    }
  return 0;
}

#endif

Return to:

Send suggestions and report system problems to the System administrator.