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/*
* __getpwent.c - This file is part of the libc-8086/pwd package for ELKS,
* Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <pwd.h>
#define PWD_BUFFER_SIZE 256
/* This isn't as flash as my previous version -- it doesn't dynamically
scale down the gecos on too-long lines, but it also makes fewer syscalls,
so it's probably nicer. Write me if you want the old version. Maybe I
should include it as a build-time option... ?
-Nat <ndf@linux.mit.edu> */
struct passwd *
__getpwent(int pwd_fd)
{
static char line_buff[PWD_BUFFER_SIZE];
static struct passwd passwd;
char * field_begin;
char * endptr;
char * gid_ptr;
char * uid_ptr;
int line_len;
int i;
/* We use the restart label to handle malformatted lines */
restart:
/* Read the passwd line into the static buffer using a minimal of
syscalls. */
if ((line_len=read(pwd_fd, line_buff, PWD_BUFFER_SIZE))<=0)
return NULL;
field_begin=strchr(line_buff, '\n');
if (field_begin!=NULL)
lseek(pwd_fd, (long) (1+field_begin-(line_buff+line_len)), SEEK_CUR);
else /* The line is too long - skip it. :-\ */
{
do { if ((line_len=read(pwd_fd, line_buff, PWD_BUFFER_SIZE))<=0)
return NULL;
} while (!(field_begin=strchr(line_buff, '\n')));
lseek(pwd_fd, (long) (field_begin-line_buff)-line_len+1, SEEK_CUR);
goto restart;
}
if (*line_buff=='#' || *line_buff==' ' || *line_buff=='\n' ||
*line_buff=='\t')
goto restart;
*field_begin='\0';
/* We've read the line; now parse it. */
field_begin=line_buff;
for (i=0;i<7;i++)
{
switch(i)
{
case 0: passwd.pw_name=field_begin; break;
case 1: passwd.pw_passwd=field_begin; break;
case 2: uid_ptr=field_begin; break;
case 3: gid_ptr=field_begin; break;
case 4: passwd.pw_gecos=field_begin; break;
case 5: passwd.pw_dir=field_begin; break;
case 6: passwd.pw_shell=field_begin; break;
}
if (i<6)
{
field_begin=strchr(field_begin, ':');
if (field_begin==NULL) goto restart;
*field_begin++='\0';
}
}
passwd.pw_gid=(gid_t) strtoul(gid_ptr, &endptr, 10);
if (*endptr!='\0') goto restart;
passwd.pw_uid=(uid_t) strtoul(uid_ptr, &endptr, 10);
if (*endptr!='\0') goto restart;
return &passwd;
}
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