setpwent(3) — Linux manual page


GETPWENT(3)               Linux Programmer's Manual              GETPWENT(3)

NAME         top

       getpwent, setpwent, endpwent - get password file entry

SYNOPSIS         top

       #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 since 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       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

       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

RETURN VALUE         top

       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 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         top

       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.

FILES         top

              local password database file

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │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.

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.  The pw_gecos field is not
       specified in POSIX, but is present on most implementations.

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

GNU                              2017-09-15                      GETPWENT(3)

Pages that refer to this page: getent(1)fgetpwent(3)fgetpwent_r(3)getpw(3)getpwent_r(3)getpwnam(3)getpwnam_r(3)getpwuid(3)getpwuid_r(3)putpwent(3)nss(5)