getpwnam man page on CentOS

Man page or keyword search:  
man Server   8420 pages
apropos Keyword Search (all sections)
Output format
CentOS logo
[printable version]

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

NAME
       getpwnam, getpwnam_r, getpwuid, getpwuid_r - get password file entry

SYNOPSIS
       #include <sys/types.h>
       #include <pwd.h>

       struct passwd *getpwnam(const char *name);

       struct passwd *getpwuid(uid_t uid);

       int getpwnam_r(const char *name, struct passwd *pwbuf,
	       char *buf, size_t buflen, struct passwd **pwbufp);

       int getpwuid_r(uid_t uid, struct passwd *pwbuf,
	       char *buf, size_t buflen, struct passwd **pwbufp);

DESCRIPTION
       The getpwnam() function returns a pointer to a structure containing the
       broken-out fields of the record in the  password	 database  (e.g.,  the
       local  password	file /etc/passwd, NIS, and LDAP) that matches the user
       name name.

       The getpwuid() function returns a pointer to a structure containing the
       broken-out  fields  of the record in the password database that matches
       the user ID uid.

       The getpwnam_r() and getpwuid_r() functions obtain  the	same  informa‐
       tion,  but store the retrieved passwd structure in the space pointed to
       by pwbuf.  This passwd structure	 contains  pointers  to	 strings,  and
       these  strings  are stored in the buffer buf of size buflen.  A pointer
       to the result (in case of success) or NULL (in case no entry was	 found
       or an error occurred) is stored in *pwbufp.

       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 */
	 };

       The  maximum needed size for buf can be found using sysconf(3) with the
       _SC_GETPW_R_SIZE_MAX parameter.

RETURN VALUE
       The getpwnam() and getpwuid() functions return a pointer	 to  a	passwd
       structure,  or  NULL  if	 the  matching	entry is not found 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 static area, and may  be  overwritten  by
       subsequent calls to getpwent(), getpwnam(), or getpwuid().

       The  getpwnam_r() and getpwuid_r() functions return zero on success. In
       case of error, an error number is returned.

ERRORS
       0 or ENOENT or ESRCH or EBADF or EPERM or ...
	      The given name or uid was not found.

       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

NOTES
       The  formulation given above under "RETURN VALUE" is from POSIX.1-2001.
       It does not call "not found" an error, and hence does not specify  what
       value  errno might have in this situation. But that makes it impossible
       to recognize errors. One might argue  that  according  to  POSIX	 errno
       should be left unchanged if an entry is not found. Experiments on vari‐
       ous Unix-like systems show that lots of different values occur in  this
       situation:  0,  ENOENT,	EBADF,	ESRCH, EWOULDBLOCK, EPERM and probably
       others.

       The pw_dir field contains the name of the initial working directory  of
       the user.  Login programs use the value of this field to initialize the
       HOME environment variable for the login	shell.	 An  application  that
       wants  to  determine its user's home directory should inspect the value
       of HOME (rather than the value getpwuid(getuid())->pw_dir)  since  this
       allows the user to modify their notion of "the home directory" during a
       login session.  To determine the (initial) home	directory  of  another
       user, it is necessary to use getpwnam("username")->pw_dir or similar.

SEE ALSO
       endpwent(3),  fgetpwent(3),  getgrnam(3),  getpw(3), getpwent(3), putp‐
       went(3), setpwent(3), passwd(5)

GNU				  1996-05-27			   GETPWNAM(3)
[top]

List of man pages available for CentOS

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net