How To Completely Remove User Account In Unix (Linux)

How do I remove a user’s access from my server? How do I delete a user account under Linux operating systems?

You need to use the userdel command to delete a user account and related files from user account or use this perl script:

/#!/usr/bin/perl
use strict;
use warnings;
use Fcntl ':flock'; # import LOCK_* constants

if ($#ARGV != 0) {
print STDERR "Usage is $0 <user>\n";
exit (8);
}

my $user = $ARGV[0];

sub edit_file($)
{
my $file = shift;

open IN_FILE, "<$file" or
die("Could not open $file for input");

open OUT_FILE, ">$file.new" or
die("Could not open $file.new for output");

while (1) {
my $line = <IN_FILE>;
if (not defined($line)) {
last;
}
if ($line =~ /^$user/) {
next;
}
print OUT_FILE $line;
}
close (IN_FILE);
close (OUT_FILE);
unlink("$file.bak");
rename("$file", "$file.bak");
rename("$file.new", $file);
}

my @info = getpwnam($user);
if (@info == -1) {
die("No such user $user");
}

open PW_FILE, "</etc/passwd" or
die("Could not read /etc/passwd");

# Lock the file for the duration of the program
flock PW_FILE, LOCK_EX;

edit_file("/etc/group");
edit_file("/etc/shadow");

if ($info[7] eq "/home/$user") {
system("rm -rf /home/$user");
} else {
print "User has a non-standard home directory.\n";
print "Please remove manually.\n";
print "Directory = $info[7]\n";
}
print "User $user -- Deleted\n";

edit_file("/etc/passwd");

flock(PW_FILE,LOCK_UN);
close(PW_FILE);</p>

This script  must be run as root user.

Running the script

root@bt:~/src/perl# ./del_user_a.pl
Usage is ./del_user_a.pl <user>
root@bt:~/src/perl# ./del_user_a.pl wysocand

Running On BackTrack 5R2

 

Source:

• Userdel -http://linux.die.net/man/8/userdel
• Userdel – http://linuxers.org/howto/how-add-remove-user-accounts-linux
• Perl for System Administration – http://www.unix.org.ua/orelly/perl/sysadmin/index.htm