GETPWENT

Section: Linux Programmer's Manual (3)
Updated: 2009-03-30
Index Return to Main Contents
 

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);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

getpwent(), setpwent(), endpwent(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE > = 500  

DESCRIPTION

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 it 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;      /* real name */
    char   *pw_dir;        /* home directory */
    char   *pw_shell;      /* shell program */
};
 

RETURN VALUE

The getpwent() function returns a pointer to a passwd structure, or NULL if there are no more entries or an error occurs. 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).)  

ERRORS

EINTR
A signal was caught.
EIO
I/O error.
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

fgetpwent(3), getpw(3), getpwent_r(3), getpwnam(3), getpwuid(3), putpwent(3), passwd(5)  

COLOPHON

This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.