getpwent(3)

Name

getpwent, getpwuid, getpwnam, setpwent, endpwent, setpwfile − get password entry

Syntax

#include <pwd.h>

struct passwd *getpwent()

struct passwd *getpwuid(uid)
uid_t uid;

struct passwd *getpwnam(name)
char *name;

void setpwent()

void endpwent()

void setpwfile(pathname)
char *pathname

Description

The routines, getpwent, getpwuid and getpwnam, each return a pointer to an object with the following structure containing the broken-out fields of a line in the password database:

struct passwd { /* see getpwent(3) */
        char    *pw_name;
        char    *pw_passwd;
        uid_t    pw_uid;
        gid_t    pw_gid;
        int      pw_quota;
        char    *pw_comment;
        char    *pw_gecos;
        char    *pw_dir;
        char    *pw_shell;
};
struct passwd *getpwent(), *getpwuid(), *getpwnam();

The fields pw_quota and pw_comment are unused; the others have meanings described in passwd(.).

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

The getpwent subroutine simply retieves the next entry while getpwuid and getpwnam search until a matching uid or name is found (or until all entries are exhausted). The getpwent subroutine keeps a pointer in the database, allowing successive calls to be used to search the entire database.

A call to setpwent must be made before a while loop using getpwent in order to perform initialization and an endpwent must be used after the loop. Both getpwuid and getpwnam make calls to setpwent and endpwent.

The setpwfile subroutine sets the pathname of the ASCII passwd file and optional hashed database to be used for local passwd lookups. If a passwd file has been left open by a call to setpwent or getpwent, setpwfile will close it first. Setpwfile does not directly affect the use of distributed passwd databases.

Restrictions

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

If YP is running, getpwent does not return the entries in any particular order. See the Guide to the Yellow Pages Service for setup information.

The password database may also be distributed via the BIND/Hesiod naming service. See the Guide to the BIND/Hesiod Service for more information.

Return Value

Null pointer (0) returned on EOF or error.

Files

/etc/passwd

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