GETPWENT(3C) (C Programming Language Utilities) GETPWENT(3C)
NAME
getpwent, getpwuid, getpwnam, setpwent, endpwent, fgetpwent
- get password file entry
SYNOPSIS
#include <pwd.h>
struct passwd *getpwent ( )
struct passwd *getpwuid (uid)
int uid;
struct passwd *getpwnam (name)
char *name;
void setpwent ( )
void endpwent ( )
struct passwd *fgetpwent (f)
FILE *f;
DESCRIPTION
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;
int pw_uid;
int pw_gid;
char *pw_age;
char *pw_comment;
char *pw_gecos;
char *pw_dir;
char *pw_shell;
};
Page 1 May 1989
GETPWENT(3C) (C Programming Language Utilities) GETPWENT(3C)
This structure is declared in <pwd.h> so it is not necessary
to redeclare it.
The fields have meanings described in passwd(4).
getpwent when first called returns a pointer to the first
passwd structure in the file; thereafter, it returns a
pointer to the next passwd structure in the file; so
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
SEE ALSO
getlogin(3C), getgrent(3C), passwd(4).
DIAGNOSTICS
A NULL pointer is returned on EOF or error.
WARNING
The above routines use <stdio.h>, which causes them to
increase the size of programs, not otherwise using standard
I/O, more than might be expected.
CAVEAT
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GETPWENT(3C) (C Programming Language Utilities) GETPWENT(3C)
All information is contained in a static area, so it must be
copied if it is to be saved.
Page 3 May 1989