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 ( )

SYNOPSIS (SYSV.2)

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.  The structure has the following members:

char ∗pw_name;
char ∗pw_passwd;
uid_tpw_uid;
gid_tpw_gid;
int  pw_quota;
char ∗pw_age;
char ∗pw_comment;
char ∗pw_gecos;
char ∗pw_dir;
char ∗pw_shell;
};

This structure is declared in <pwd.h> so it is not necessary to redeclare it.

The pw_comment field is unused; the others 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. 

SECURITY FEATURES

In CX/SX, the encrypted passwords are kept in /mls/passwd which is unreadable except by components of the Trusted Computing Base.  The file "/etc/passwd" is a user visible "shadow" password file which is identical to the real password file (i.e. /mls/passwd) except that the password field contains an

If the effective-user-id of the process is "root" then getpwent, getpwuid and getpwnam attempt to open the "/mls/passwd" file.  If this fails then they attempt to open the user visible copy of the password file (/etc/passwd). 

FILES

/etc/passwd /mls/passwd

SEE ALSO

updatepwgr(1SX), 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. 

BUGS

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

CX/UX Programmer’s Reference Manual