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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | FILES | ATTRIBUTES | VERSIONS | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
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getpwent(3) Library Functions Manual getpwent(3)
getpwent, setpwent, endpwent - get password file entry
Standard C library (libc, -lc)
#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 >= 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 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 to indicate the error. 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.
The pw_gecos field is not specified in POSIX, but is present on
most implementations.
POSIX.1-2008.
POSIX.1-2001, SVr4, 4.3BSD.
fgetpwent(3), getpw(3), getpwent_r(3), getpwnam(3), getpwuid(3),
putpwent(3), passwd(5)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.9.1 2024-05-02 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), genhomedircon(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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