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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | FILES | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON |
GETPWENT(3) Linux Programmer's Manual GETPWENT(3)
getpwent, setpwent, endpwent - get password file entry
#include <sys/types.h>
#include <pwd.h>
struct passwd *getpwent(void);
void setpwent(void);
void endpwent(void);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getpwent(), setpwent(), endpwent():
_XOPEN_SOURCE >= 500
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
The getpwent() function returns a pointer to a structure containing
the broken-out fields of a record from the password database (e.g.,
the local password file /etc/passwd, NIS, and LDAP). The first time
getpwent() is called, it returns the first entry; thereafter, it
returns successive entries.
The setpwent() function rewinds to the beginning of the password
database.
The endpwent() function is used to close the password database after
all processing has been performed.
The passwd structure is defined in <pwd.h> as follows:
struct passwd {
char *pw_name; /* username */
char *pw_passwd; /* user password */
uid_t pw_uid; /* user ID */
gid_t pw_gid; /* group ID */
char *pw_gecos; /* user information */
char *pw_dir; /* home directory */
char *pw_shell; /* shell program */
};
For more information about the fields of this structure, see
passwd(5).
The getpwent() function returns a pointer to a passwd structure, or
NULL if there are no more entries or an error occurred. If an error
occurs, errno is set appropriately. If one wants to check errno
after the call, it should be set to zero before the call.
The return value may point to a static area, and may be overwritten
by subsequent calls to getpwent(), getpwnam(3), or getpwuid(3). (Do
not pass the returned pointer to free(3).)
EINTR A signal was caught; see signal(7).
EIO I/O error.
EMFILE The per-process limit on the number of open file descriptors
has been reached.
ENFILE The system-wide limit on the total number of open files has
been reached.
ENOMEM Insufficient memory to allocate passwd structure.
ERANGE Insufficient buffer space supplied.
/etc/passwd
local password database file
For an explanation of the terms used in this section, see
attributes(7).
┌────────────┬───────────────┬─────────────────────────────┐
│Interface │ Attribute │ Value │
├────────────┼───────────────┼─────────────────────────────┤
│getpwent() │ Thread safety │ MT-Unsafe race:pwent │
│ │ │ race:pwentbuf locale │
├────────────┼───────────────┼─────────────────────────────┤
│setpwent(), │ Thread safety │ MT-Unsafe race:pwent locale │
│endpwent() │ │ │
└────────────┴───────────────┴─────────────────────────────┘
In the above table, pwent in race:pwent signifies that if any of the
functions setpwent(), getpwent(), or endpwent() are used in parallel
in different threads of a program, then data races could occur.
POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. The pw_gecos field is not
specified in POSIX, but is present on most implementations.
fgetpwent(3), getpw(3), getpwent_r(3), getpwnam(3), getpwuid(3),
putpwent(3), passwd(5)
This page is part of release 4.12 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2016-03-15 GETPWENT(3)
Pages that refer to this page: getent(1), pmcd(1), pmdapipe(1), fgetpwent(3), getpw(3), getpwent_r(3), getpwnam(3), getspnam(3), getspnam(3@@shadow-utils), putpwent(3), setaliasent(3), shadow(3), nss(5), nsswitch.conf(5), passwd(5)