GETPWENT
NAME
getpwent, setpwent, endpwent - get password file entry
SYNOPSIS
#include <sys/types.h>
#include <pwd.h>
struct passwd *getpwent(void);
void setpwent(void);
void endpwent(void);
DESCRIPTION
The
R 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
R /etc/passwd ,
NIS, and LDAP).
The first time it
is called it returns the first entry; thereafter, it returns successive
entries.
The
R setpwent ()
function rewinds to the beginning
of the password database.
The
R 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; /* user name */
char *pw_passwd; /* user password */
uid_t pw_uid; /* user ID */
gid_t pw_gid; /* group ID */
char *pw_gecos; /* real name */
char *pw_dir; /* home directory */
char *pw_shell; /* shell program */
};
When
shadow(5)
passwords are enabled (which is default on many GNU/Linux
installations) the content of
pw_passwd
is usually not very useful. In such a case most passwords are stored
in a separate file.
The variable
pw_shell
may be empty, in which case the system will execute the default shell
(/bin/sh)
for the user.
RETURN VALUE
The
R getpwent ()
function returns a pointer to a
passwd
structure, or NULL if
there are no more entries or an error occured.
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.
ERRORS
EINTR
A signal was caught.
EMFILE
The maximum number
(OPEN_MAX)
of files was open already in the calling process.
ENFILE
The maximum number of files was open already in the system.
ENOMEM
Insufficient memory to allocate passwd structure.
ERANGE
Insufficient buffer space supplied.
FILES
/etc/passwd
local password database file
CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001.
SEE ALSO
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