I'm looking for a way of mapping a uid (unique number representing a system user) to a user name using Perl.
Please don't suggest greping /etc/passwd :)
Edit
As a clarification, I wasn't looking for a solution that involved reading /etc/passwd explicitly. I realize that under the hood any solution would end up doing this, but I was searching for a library function to do it for me.
The standard function getpwuid, just like the same C function, gets user information based on its ID. No uses needed:
my ($name) = getpwuid(1000);
print $name,"\n";
Although it eventually reads /etc/passwd file, using standard interfaces is much more clear for other users to see, let alone it saves you some keystrokes.
Read /etc/passwd and hash the UID to login name.
Edit:
$uid = getpwnam($name);
$name = getpwuid($num);
$name = getpwent();
$gid = getgrnam($name);
$name = getgrgid($num);
$name = getgrent();
As you can see, regardless of which one you pick, the system call reads from /etc/passwd (see this for reference)
Actually I would suggest building a hash based on /etc/passwd :-) This should work well as the user ids are required to be unique.
Related
Preface: Please tell me a better way of doing this if you know of any! Even if it changes everything.
I have a powershell script that works with Net-SNMP to store the current value of an OID, change it and then check and store the values. Right now the previous and new values are stored in their own variable. There are about 160 OIDs that I need to change on >1000 nodes in my environment.
For Example for Previous and New values:
$P_vpwrSystemTempCompensation_0 = & '.\SnmpGet.exe' -q -r:"$ip" -v:2c -c:public -o:.1.3.6.1.4.1.13858.2.2.1.0
$N_vpwrSystemTempCompensation_0 = & '.\SnmpGet.exe' -q -r:"$ip" -v:2c -c:public -o:.1.3.6.1.4.1.13858.2.2.1.0
I'm try to figure the best way to store these and output into an CSV. I would like it to be formatted liked this:
Each CSV will be saved with the name and IP of the node I'm hitting.
You can make an object like this in a loop, and that could be exported to csv:
$oid = 'vpwrSystemTempCompensation.0'
$prev = 2
$new = 4647
[pscustomobject]#{OID=$oid; Previous=$prev; New=$new}
OID Previous New
--- -------- ---
vpwrSystemTempCompensation.0 2 5647
By the way, you don't need the call operator to run smnpget, if you don't put it in quotes:
.\SnmpGet.exe -q -r:$ip -v:2c -c:public -o:.1.3.6.1.4.1.13858.2.2.1.0
I'm new to do this language and i'm trying to code my own bot. I alredy got the basics and manage to use variables and aliases, however i was looking forward to do a mini-game in my chat in which you could have your own pet, name it and level it up.
I could do all this, however my problem resides in that at the end of the day, i would close the program and all the pets would go away, and that kind of destroys the purpose of it.
I was wondering if there was any way in i could save these variables and reload them each time i open the program, maybe save them on a .txt?
Any suggestion are greatly appreciated.
I agree with one of the comments that it's best to go with .ini files for this problem.
An example of the syntax, taken from the url linked above:
writeini reminder.ini birthday jenna 2/28/1983
writeini reminder.ini birthday Mike 10/10/1990
This produces the following file:
[birthday]
jenna = 2/28/1983
Mike = 10/10/1990
And is to be read like this:
echo -a Mike: $readini(reminder.ini, n, birthday, mike)
echo -a Jenna: $readini(reminder.ini, n, birthday, jenna)
If you want more flexibility to define your own data format, you can also revert to plain text files. The basic /write and $read functions have some pretty neat functionality: see the docs
Something like this should work for writing:
; search if the pet is already saved
$read(pets.txt,ns,%petname)
if ($readn == 0) {
; append to end of file
write pets.txt %petname %age %mood
}
else {
; replace line
write -l $readn pets.txt %petname %age %mood
}
To retrieve specific pets:
var %pet_info = $read(pets.txt, ns, %petname)
; Split the found line on space (ASCII-code 32)
tokenize 32 %pet_info
var %age = $2
var %mood = $3
This returns the line that starts with the petname you're looking for.
How would you do a one may mapping between a string and a UUID in perl.
I need integrate a legacy perl system that assigns users usernames, with a java system that assigns users a UUID.
(Only needs to be one way, that is, username to UUID, I don't need to go back the other way)
I was thinking something like this, although I bet theres a much simpler way:
#!/usr/bin/perl
use strict;
use Digest::MD5 qw(md5_hex);
my $username = "bob";
my $hash = md5_hex($username);
my $uuid = substr($hash, 0, 8)."-".substr($hash,8,4)."-".substr($hash,12,4)."-".substr($hash,16,4)."-".substr($hash,20,32);
print "$uuid\n";
I would suggest following RFC 4122's guidelines on generating UUIDs from names.
First, generate a random UUID and store it as part of your app / configuration.
Then:
use Data::UUID;
my $ug = Data::UUID->new;
my $namespace = $ug->from_string("65faad2c-7841-4b60-a7f4-560db1c5e683");
my $uuid = $ug->create_from_name_str($namespace, $username);
Where you replace "65faad2c-7841-4b60-a7f4-560db1c5e683" with your own randomly generated UUID.
This is guaranteed to generate valid UUIDs (your md5 method isn't), and if you ever have another legacy app that needs to be imported into the new system, conflicts will be avoided just by giving that app its own random UUID to use as a seed.
I am working on a user login and am having trouble with the user creation part. My problem is that I am trying to check the input username against a text file to see if that username already exists. I can't seem to get it to compare the input username to the array that I have brought in. I have tried two different ways of accomplishing this. One using an array and another using something I read online that I don't quite understand. Any help or explanation would be greatly appreciated.
Here is my attempt using an array to compare off of
http://codepad.org/G7xmsf3z
Here is my second attempt
http://codepad.org/SbeqmdbG
In your first attempt, try to put the if inside of the loop:
foreach my $pair(#incomingarray) {
(my $name,my $value) = split (/:/, $pair);
if ($name eq $username) {
print p("Username is already taken, try again");
close(YYY);
print end_html();
}
else {
open(YYY, ">>password.txt");
print YYY $username.":".$hashpass."\n";
print p("Your account has been created sucessfully");
close(YYY);
print end_html();
}
}
In you second attempt, I think you should try and change the line:
if (%users eq $username) {
with this one:
if (defined $users{$username}) {
As has been stated above regarding locking the flatfile from other processes there is the issue with scaling too. the more users you have the slower the lookup will be.
I started years ago with a flat file, believing I would never scale enough to require a real database and didn't want to learn how to use mySQL for example. Eventually after flatfile corruptions and long lookup times I had no choice but to move to a database.
Later you will find yourself wanting to store user preferences and such, it's easy to add a new field to a database. Flatfile will end up having the overhead of splitting each line into separate fields.
I'd suggest you do it properly with a database.
As in my comment, you should not be using a flatfile to hold your user info. You should use a proper database that will handle concurrent access for you rather than having to understand and code up how to deal with all of that yourself!
If you insist on using an array, you can search it with grep() if it is not "too large":
if (grep /^$username:/, #incomingarray) {
print "user name '$username' is already registered, try again\n";
}
else {
print "user name '$username' is not already registered\n";
}
I see some other problems in your code as well.
You should always prefer lexical (my) variables over package (our) variables.
Why do you think (erroneously) that $name and $username cannot be lexical variables?
You should always use the 3-arg form of open() and check its return value like in your 2nd code example. Your open() in the 1st code example is how it was done many many years ago.
My company, like everyone else's, requires password resets from time to time. This is all good and well for security's sake, but I'd like to explore the challenge of resetting it through a script (notably because we can't use our previous 25 passwords; Perl is much quicker about cycling through a list two-dozen deep than my fingers are).
I'm trying to use Perl and Win32::OLE's LDAP connectors to reset my password. I've followed a couple of examples online, and have, briefly:
use strict;
use Win32::OLE;
my $dn = 'cn=name,dc=corp,dc=com';
my $ldap = Win32::OLE->GetObject('LDAP:');
my $ldap_user = $ldap->OpenDSObject('LDAP://' . $dn,'username','password',1);
$ldap_user->SetPassword('mySw337NewPassword');
And all I get for my troubles is:
Win32::OLE(0.1707) error 0x80070005: "Access is denied"
in METHOD/PROPERTYGET "SetPassword" at pw.change.pl line 8
Is this something that can be worked around? I've located the Net::LDAP::Extension::SetPassword module, but no dice there.
Thanks!
Update for Leon (Max, you're next):
You're correct, I should have specified better. I tried Win32::OLE, failed, then separately tried Net::LDAP::Extension::SetPassword and failed even harder.
As for my server: I'm not certain, I'm not the LDAP guy :) By running ->root_dse->get_value('supportedExtension') I can see that the setPassword OID is not set, so maybe it's just not meant to be.
Final props to barneyton!
Final solution:
use strict;
use Win32::OLE;
my $orig_password = 'password123Test';
my $target_password = 'password321Test';
my $dn = 'cn=myname,dc=corp,dc=com';
my $ldap = Win32::OLE->GetObject('LDAP:');
my $ldap_user = $ldap->OpenDSObject('LDAP://'.$dn,'myname',$orig_password,1);
my $tmp_password = '';
for ( my $i = 0; $i < 30; ++$i )
{
$tmp_password = 'password' . $i . 'ABC';
print 'Changing to ' . $tmp_password . "\n";
$ldap_user->ChangePassword($orig_password,$tmp_password);
$orig_password = $tmp_password;
sleep 1;
}
$ldap_user->ChangePassword($tmp_password,$target_password);
When you said you were trying to "reset" your password, I think you really meant change password rather than set password. There is a difference between the two. "SetPassword" requires god/admin privilege since you are setting a user's password to a new value regardless of whether the old password is known, while "ChangePassword" requires the user to actually know the old password. I'm assuming your account does not have admin privilege, else you would not have gotten 0x80070005: "Access is denied"
So instead of:
$ldap_user->SetPassword('mySw337NewPassword');
try this:
$ldap_user->ChangePassword('password', 'mySw337NewPassword');
By the way, I've never done this stuff in perl, so I'm just guessing. Hope this helps you out.
Net::LDAP::Extension::SetPassword doesn't have anything to do with any OLE LDAP object. Either you use Net::LDAP, or you use Win32::OLE->GetObject('LDAP:').
You didn't mention what server you're using. Setting passwords requires an extension to LDAP, so that is relevant.
Another thing to keep in mind is Active Directory does not let you set passwords unless you bind to port 636 using LDAPS.
You could try to write the value to userPassword which would be a password reset, and you might not have rights to do that.
Otherwise you could try in one operation (LDIF would show it as separated by a single dash on a line) remove the value of the old password and then add the value of the new password. That would be a password change event.