fgetpwent.c
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/* GNU mailutils - a suite of utilities for electronic mail
Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
This program 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.
This program 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 this program; 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