1/* Copyright (C) 1991-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <stdio.h>
20#include <pwd.h>
21#include <stdlib.h>
22#include <nss.h>
23
24#define _S(x) x ?: ""
25
26/* Write an entry to the given stream. This must know the format of
27 the password file. If the input contains invalid characters,
28 return EINVAL, or replace them with spaces (if they are contained
29 in the GECOS field). */
30int
31putpwent (const struct passwd *p, FILE *stream)
32{
33 if (p == NULL || stream == NULL
34 || p->pw_name == NULL || !__nss_valid_field (value: p->pw_name)
35 || !__nss_valid_field (value: p->pw_passwd)
36 || !__nss_valid_field (value: p->pw_dir)
37 || !__nss_valid_field (value: p->pw_shell))
38 {
39 __set_errno (EINVAL);
40 return -1;
41 }
42
43 int ret;
44 char *gecos_alloc;
45 const char *gecos = __nss_rewrite_field (value: p->pw_gecos, to_be_freed: &gecos_alloc);
46
47 if (gecos == NULL)
48 return -1;
49
50 if (p->pw_name[0] == '+' || p->pw_name[0] == '-')
51 ret = fprintf (stream, "%s:%s:::%s:%s:%s\n",
52 p->pw_name, _S (p->pw_passwd),
53 gecos, _S (p->pw_dir), _S (p->pw_shell));
54 else
55 ret = fprintf (stream, "%s:%s:%lu:%lu:%s:%s:%s\n",
56 p->pw_name, _S (p->pw_passwd),
57 (unsigned long int) p->pw_uid,
58 (unsigned long int) p->pw_gid,
59 gecos, _S (p->pw_dir), _S (p->pw_shell));
60
61 free (ptr: gecos_alloc);
62 if (ret >= 0)
63 ret = 0;
64 return ret;
65}
66

source code of glibc/pwd/putpwent.c