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 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

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
       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 */
           };

       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.

       For more information about the fields of this structure, see passwd(5).

RETURN VALUE

       The  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.

       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

ATTRIBUTES

   Multithreading (see pthreads(7))
       The getpwent() function is not thread-safe.

       The setpwent() and endpwent() functions are thread-safe.

CONFORMING TO

       SVr4, 4.3BSD, POSIX.1-2001.  The pw_gecos field is not  specified  in  POSIX,  but  is  present  on  most
       implementations.

SEE ALSO

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

COLOPHON

       This  page  is  part  of  release 3.54 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/.