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116 lines
3.1 KiB
C
116 lines
3.1 KiB
C
/*
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* __getpwent.c - This file is part of the libc-8086/pwd package for ELKS,
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* Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free
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* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <fcntl.h>
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#include "pwd_.h"
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#include "busybox.h"
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#define PWD_BUFFER_SIZE 256
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/* This isn't as flash as my previous version -- it doesn't dynamically
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scale down the gecos on too-long lines, but it also makes fewer syscalls,
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so it's probably nicer. Write me if you want the old version. Maybe I
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should include it as a build-time option... ?
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-Nat <ndf@linux.mit.edu> */
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struct passwd *__getpwent(int pwd_fd)
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{
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static char line_buff[PWD_BUFFER_SIZE];
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static struct passwd passwd;
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char *field_begin;
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char *endptr;
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char *gid_ptr=NULL;
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char *uid_ptr=NULL;
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int line_len;
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int i;
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/* We use the restart label to handle malformatted lines */
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restart:
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/* Read the passwd line into the static buffer using a minimal of
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syscalls. */
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if ((line_len = read(pwd_fd, line_buff, PWD_BUFFER_SIZE)) <= 0)
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return NULL;
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field_begin = strchr(line_buff, '\n');
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if (field_begin != NULL)
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lseek(pwd_fd, (long) (1 + field_begin - (line_buff + line_len)),
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SEEK_CUR);
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else { /* The line is too long - skip it. :-\ */
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do {
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if ((line_len = read(pwd_fd, line_buff, PWD_BUFFER_SIZE)) <= 0)
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return NULL;
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} while (!(field_begin = strchr(line_buff, '\n')));
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lseek(pwd_fd, (long) (field_begin - line_buff) - line_len + 1,
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SEEK_CUR);
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goto restart;
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}
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if (*line_buff == '#' || *line_buff == ' ' || *line_buff == '\n' ||
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*line_buff == '\t')
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goto restart;
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*field_begin = '\0';
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/* We've read the line; now parse it. */
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field_begin = line_buff;
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for (i = 0; i < 7; i++) {
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switch (i) {
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case 0:
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passwd.pw_name = field_begin;
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break;
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case 1:
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passwd.pw_passwd = field_begin;
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break;
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case 2:
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uid_ptr = field_begin;
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break;
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case 3:
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gid_ptr = field_begin;
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break;
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case 4:
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passwd.pw_gecos = field_begin;
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break;
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case 5:
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passwd.pw_dir = field_begin;
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break;
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case 6:
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passwd.pw_shell = field_begin;
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break;
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}
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if (i < 6) {
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field_begin = strchr(field_begin, ':');
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if (field_begin == NULL)
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goto restart;
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*field_begin++ = '\0';
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}
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}
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passwd.pw_gid = (gid_t) strtoul(gid_ptr, &endptr, 10);
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if (*endptr != '\0')
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goto restart;
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passwd.pw_uid = (uid_t) strtoul(uid_ptr, &endptr, 10);
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if (*endptr != '\0')
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goto restart;
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return &passwd;
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}
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