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.
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