getpwent(3C)


getpwent, getpwuid, getpwnam, setpwent, endpwent, fgetpwent -- return pointer to password file entry

Synopsis

   #include <pwd.h> 
   

#include <stdio.h>

struct passwd *getpwent (void);

struct passwd *getpwuid (uid_t uid);

struct passwd *getpwnam (const char *name);

void setpwent (void);

void endpwent (void);

struct passwd *fgetpwent (FILE *f);

Description

getpwuid- return pointer to password entry uid

getpwnam- return pointer to password entry name

setpwent- rewind password file for further searches

endpwent- close password file

fgetpwent- return pointer to next password structure in stream

getpwent, getpwuid, and getpwnam each returns a pointer to an object with the following structure containing the broken-out fields of a line in the /etc/passwd file. Each line in the file contains a passwd structure, declared in the ``pwd.h'' header file:

   struct passwd { 
   	char	*pw_name; 
   	char	*pw_passwd; 
   	uid_t	pw_uid; 
   	gid_t	pw_gid; 
   	char	*pw_age; 
   	char	*pw_comment; 
   	char	*pw_gecos; 
   	char	*pw_dir; 
   	char	*pw_shell; 
   }; 

When first called, getpwent returns a pointer to the first passwd structure in the file; thereafter, it returns a pointer to the next passwd structure in the file. Thus successive calls can be used to search the entire file. getpwuid searches from the beginning of the file until a numerical user ID matching uid is found and returns a pointer to the particular structure in which it was found. getpwnam searches from the beginning of the file until a login name matching name is found, and returns a pointer to the particular structure in which it was found. If an end-of-file or an error is encountered on reading, these functions return a null pointer.

A call to setpwent has the effect of rewinding the password file to allow repeated searches. endpwent may be called to close the password file when processing is complete.

fgetpwent returns a pointer to the next passwd structure in the stream f, which matches the format of /etc/passwd.

Files

/etc/passwd
/var/yp/domainame/passwd.byname
/var/yp/domainame/passwd.byuid

Return values

getpwent, getpwuid, getpwnam, and fgetpwent return a null pointer on EOF or error.

References

getgrent(3C), getlogin(3C), passwd(4)

Notices

All information is contained in a static area, so it must be copied if it is to be saved.

Passwd structures will be obtained from NIS, when the dynamic versions of these routines are used and NIS is installed and running. See passwd(4) for the formats of NIS entries.


30 January 1998
© 1998 The Santa Cruz Operation, Inc. All rights reserved.