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posix_getpwnamLiefert zu einem Benutzernamen Informationen über diesen Benutzer


posix_getpwnam(string $username): array|false

Gibt ein Array mit Informationen über den angegebenen Benutzer zurück.



Ein alphanumerischer Benutzername


Bei Erfolg wird ein Array mit den folgenden Elementen zurückgegeben, andernfalls false:

Das Benutzerinformation-Array
Element Beschreibung
name Das name-Element enthält den Benutzernamen. Es handelt sich dabei nicht um den wirklichen, kompletten Namen, sondern um einen kurzen "Bezeichner" des Benutzers mit normalerweise weniger als 16 Zeichen. Der Benutzername sollte derselbe wie der bei Aufruf der Funktion verwendete Parameter username sein und ist von daher redundant.
passwd Das passwd-Element enthält das verschlüsselte Passwort des Benutzers. Häufig, zum Beispiel wenn auf einem System "shadow"-Passwörter verwendet werden, wird stattdessen ein Sternchen zurückgegeben.
uid Die Benutzer-ID in numerischem Format.
gid Die Gruppen-ID des Benutzers. Benutzen Sie die Funktion posix_getgrgid(), um den Gruppennamen und eine Liste der Gruppenmitglieder aufzulösen.
gecos GECOS ist ein veralteter Begriff, der sich auf das finger-Informationsfeld auf einem Honeywell-Stapelverarbeitungssystem bezieht. Das Feld gibt es aber immer noch und sein Inhalt wurde durch POSIX formalisiert. Es enthält eine durch Komma getrennte Liste, bestehend aus dem kompletten Namen der Benutzerin, der Telefonnummer des Büros, der Zimmernummer des Büros und der privaten Telefonnummer. Auf den meisten Systemen ist nur der komplette Name des Benutzers verfügbar.
dir Dieses Element enthält den absoluten Pfad des Homeverzeichnisses des Benutzers.
shell Das shell-Element enthält den absoluten Pfad zur standardmäßigen Shell des Benutzers.


Beispiel #1 posix_getpwnam()-Beispiel


= posix_getpwnam("tom");


Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

    [name]    => tom
    [passwd]  => x
    [uid]     => 10000
    [gid]     => 42
    [gecos]   => "tom,,,"
    [dir]     => "/home/tom"
    [shell]   => "/bin/bash"

Siehe auch

  • posix_getpwuid() - Liefert zu einer Benutzer-ID Informationen über diesen Benutzer
  • POSIX GETPWNAM(3)-Manpage

add a note

User Contributed Notes 9 notes

darryl at pointclark dot net
22 years ago
If you need to validate a *real* unix password on a system using shadowed passwords, the posix_getpwnam() function in PHP won't work (as mentioned, 'x', or '*', will be in the password field).

I have a need to verify a user/pass within PHP (using SSL!). I don't know if this is the best way, but it's what I'm doing at the moment (works well!).

First, you need some help from the OS. I wrote a tiny C utility that does the shadow look-up for me... It requires root access to read /etc/shadow. So after you compile (gcc -O2 -s -o spasswd -lcrypt spasswd.c), you need to either use sudo to run it, or

# chown root spasswd && chmod u+s spasswd

To code that I'm using to authenticate a user/pass from PHP looks like:

function Authenticate($realm)
global $PHP_AUTH_USER;
global $PHP_AUTH_PW;

header("WWW-Authenticate: Basic realm=\"$realm\"");
header("HTTP/1.0 401 Unauthorized");

return false;
if(($fh = popen("/usr/sbin/spasswd", "w")))
fputs($fh, "$PHP_AUTH_USER $PHP_AUTH_PW");
$r = pclose($fh);

return true;

header("WWW-Authenticate: Basic realm=\"$realm\"");
header("HTTP/1.0 401 Unauthorized");

return false;

The C source for spasswd.c:

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <crypt.h>
#include <shadow.h>

static char salt[12], user[128], pass[128];

void die(void)
memset(salt, '\0', 12);
memset(user, '\0', 128);
memset(pass, '\0', 128);

int main(int argc, char *argv[])
struct spwd *passwd;

atexit(die); die();

if(fscanf(stdin, "%127s %127s", user, pass) != 2)
return 1;

if(!(passwd = getspnam(user)))
return 1;

strncpy(salt, passwd->sp_pwdp, 11);
strncpy(pass, crypt(pass, salt), 127);

if(!strncmp(pass, passwd->sp_pwdp, 127))
return 0;

return 1;

Hope this helps someone...
perreal at lyon dot cemagref dot fr
22 years ago
To check passwords on a Unix-box, look at the mod_auth_external module for Apache, it uses external programs to do the real job. The server won't ever read the encrypted password.

One of them, pwauth, can be configured to use PAM or whatever is used on your system. Users that can run this program are configured at compile time. And this program can be called from PHP with exec(...).
bau at kg-fds dot de
18 years ago
If you are running a pop3-daemon, so you can do authentification on pop3 by using fsockopen :-) and checking whether it returns +OK or -ERR
corychristison at lavacube dot net
19 years ago
For those of you who are writing daemons with PHP and are one for security. This function will not return any info if you have called PHP's chroot() function.

Took me a few minutes why it wouldn't find the user it was searching for.
marcus at nospamsynchromedia dot co dot uk
21 years ago
Given a non-existent username, this function returns a boolean FALSE.
vision_1967 at hotmail dot com
22 years ago
I needed to get access to the user information to do login/validation via an SSL connection and encountered the same problem with receiving '*' in the password field. After checking the documentation on posix_getpwnam, I saw a previous solution involving coding a C program. This was a bit bulky for me so I came up with my own solution.

Variations on this theme can probably be done to make the solution more programmer/reader friendly, but the way I did it accomplished the task that I needed to do.

IF the information you need to get from posix_getpwnam comes from a host participating in an NIS network, you can accomplish the same thing with the following command:

$autharray = split(":",`ypmatch $USER passwd`);

(pretty long explanation for such a short solution huh?)

You'll have to get at the fields by their index number ($autharray[0], $autharray[1], ...) using this method.

To create an associative array that is plug-in compatible with the posix_getpwnam function, you'll probably need to use the 'list' specifier to do the assignments.

I hope this helps someone.

sezery at damla dot net
22 years ago
User and group functions do not work on recent Redhat systems since these functions are based on /etc/group file but new redhat does not put group members' list into this file. Instead you need to examine /etc/passwd file and find members of a group by checking group id.
bau at kg-fds dot de
18 years ago
Hello, I've tried another, more easier way to check passwords than checking it to a pop3-server. If you are running a samba-server or a Windows PDC, so you can try to connect with the username/password you want to check to the netlogon of this server:

if (exec('echo "exit"|smbclient //server/netlogon -U'.$user.' '.$pass)=="") { ... }

If the username/password doesn't match, then the exec-command under LINUX returns an error.

Good luck
bau at kg-fds dot de
18 years ago
Oh I forgot the following:

to change a Users password via PHP,
you can use the following (under Linux with installed Samba):

exec('echo -e "'.$oldpassword.'\n'.$newpassword.'\n'.$newpassword.'
"|smbpasswd -U'.$user.' -s')

The exec-command returns ""
if an error occured (then see the error_log of the web-server)
or a message "The password has been changed".

Good luck.
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