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

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  getp-
       went()  is  called,  it returns the first entry; thereafter, it returns
       successive entries.
       The setpwent() function rewinds to the beginning of the password  data-
       base.
       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 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 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
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), putp-
       went(3), passwd(5)
COLOPHON
       This page is part of release 3.53 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/.

GNU                               2013-06-21                       GETPWENT(3)