| GETPWENT(3) | Library Functions Manual | GETPWENT(3) | 
getpwent, getpwent_r,
  getpwnam, getpwnam_r,
  getpwuid, getpwuid_r,
  setpassent, setpwent,
  endpwent —
#include <pwd.h>
struct passwd *
  
  getpwent(void);
int
  
  getpwent_r(struct passwd *pw,
    char *buffer, size_t buflen,
    struct passwd **result);
struct passwd *
  
  getpwnam(const
    char *name);
int
  
  getpwnam_r(const char *name,
    struct passwd *pw, char *buffer,
    size_t buflen, struct passwd
    **result);
struct passwd *
  
  getpwuid(uid_t
    uid);
int
  
  getpwuid_r(uid_t uid,
    struct passwd *pw, char *buffer,
    size_t buflen, struct passwd
    **result);
int
  
  setpassent(int
    stayopen);
void
  
  setpwent(void);
void
  
  endpwent(void);
<pwd.h>:
struct passwd {
	char	*pw_name;	/* user name */
	char	*pw_passwd;	/* encrypted password */
	uid_t	pw_uid;		/* user uid */
	gid_t	pw_gid;		/* user gid */
	time_t	pw_change;	/* password change time */
	char	*pw_class;	/* user login class */
	char	*pw_gecos;	/* general information */
	char	*pw_dir;	/* home directory */
	char	*pw_shell;	/* default shell */
	time_t	pw_expire;	/* account expiration */
};
The functions getpwnam() and
    getpwuid() search the password database for the
    given user name pointed to by name or user id pointed
    to by uid respectively, always returning the first one
    encountered. Identical user names or user ids may result in undefined
    behavior.
The getpwent() function sequentially reads
    the password database and is intended for programs that wish to process the
    complete list of users.
The functions getpwnam_r(),
    getpwuid_r(), and
    getpwent_r() act like their non re-entrant
    counterparts, updating the contents of pw and storing
    a pointer to that in result, and returning
    0. Storage used by pw is
    allocated from buffer, which is
    buflen bytes in size. If the requested entry cannot be
    found, result will point to
    NULL and 0 will be returned.
    If an error occurs, a non-zero error number will be returned and
    result will point to NULL.
    Calling getpwent_r() from multiple threads will
    result in each thread reading a disjoint portion of the password
  database.
The setpassent() function accomplishes two
    purposes. First, it causes getpwent() to
    “rewind” to the beginning of the database. Additionally, if
    stayopen is non-zero, file descriptors are left open,
    significantly speeding up subsequent accesses for all of the functions.
    (This latter functionality is unnecessary for
    getpwent() as it doesn't close its file descriptors
    by default.)
It is dangerous for long-running programs to keep the file descriptors open as the database will become out of date if it is updated while the program is running.
The setpwent() function is equivalent to
    setpassent() with an argument of zero.
The endpwent() function closes any open
    files.
These functions have been written to “shadow” the
    password file, e.g. allow only certain programs to have access to the
    encrypted password. If the process which calls them has an effective uid of
    0, the encrypted password will be returned, otherwise, the password field of
    the returned structure will point to the string
    ‘*’.
getpwent(),
  getpwnam(), and getpwuid(),
  return a valid pointer to a passwd structure on success and a
  NULL pointer if the entry was not found or an error
  occurred. If an error occurred, the global variable
  errno is set to indicate the nature of the failure.
  The setpassent() function returns 0 on failure,
  setting the global variable errno to indicate the
  nature of the failure, and 1 on success. The
  endpwent() and setpwent()
  functions have no return value. The functions
  getpwnam_r(), getpwuid_r(),
  and getpwent_r() return 0 on
  success or entry not found, and non-zero on failure, setting the global
  variable errno to indicate the nature of the failure.
setpwfile() which allowed the
  specification of alternative password databases, has been deprecated and is no
  longer available.
getpwent, getpwent_r,
  getpwnam, getpwnam_r,
  getpwuid, getpwuid_r, and
  setpassent:
EINTR]EIO]EMFILE]ENFILE]The following error code may be set in errno
    for getpwent_r, getpwnam_r,
    and getpwuid_r:
ERANGE]buffer and
      buflen.Other errno values may be set depending on
    the specific database backends.
getpwnam() and getpwuid(),
  functions conform to IEEE Std 1003.1-1990
  (“POSIX.1”). The getpwnam_r() and
  getpwuid_r() functions conform to
  IEEE Std 1003.1c-1995 (“POSIX.1c”). The
  endpwent(), getpwent(), and
  setpwent() functions conform to
  X/Open Portability Guide Issue 4, Version 2
  (“XPG4.2”) and IEEE Std 1003.1-2004
  (“POSIX.1”) (XSI extension).
getpwent, getpwnam,
  getpwuid, setpwent, and
  endpwent functions appeared in
  Version 7 AT&T UNIX. The
  setpassent function appeared in
  4.3BSD-Reno. The functions
  getpwnam_r() and getpwuid_r()
  appeared in NetBSD 3.0.
getpwent(),
  getpwnam(), and getpwuid(),
  leave their results in an internal static object and return a pointer to that
  object. Subsequent calls to any of these functions will modify the same
  object.
The functions getpwent(),
    endpwent(), setpassent(),
    and setpwent() are fairly useless in a networked
    environment and should be avoided, if possible.
    getpwent() makes no attempt to suppress duplicate
    information if multiple sources are specified in
    nsswitch.conf(5).
| February 7, 2018 | NetBSD 10.0 |