Checking name convention

zalezny has asked for the wisdom of the Perl Monks concerning the following question:

Dear Gurus, in my scripts just after execution user needs to input several information`s as a prompt answer. One of the information which needs to be checked is user name. On our server we are using special name convention which looks like this: usr123 - 3 letters and 3 diggits I would like to implement some rule which will check if user input fit to current name convention (3 letters and 3 diggits). I started writing some script but I stuck here. Maybe somebody will be able to help me.

#!/usr/bin/perl

use warnings;
use strict;

print "OS username:";
my $os_user = <>;
chomp $os_user;   #remove "\n" on the end of entered string

... ?
[download]

Thanks in advance for any ideas. Zalezny

Comment on Checking name convention Download Code

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Re: Checking name convention by AppleFritter (Vicar) on Feb 24, 2015 at 11:36 UTC
Use a regular expression: `# ... unless($os_user =~ m/^[A-Za-z]{3}[0-9]{3}$/) { die "Invalid username: $os_user"; } # ...` [download] Depending on what letters and digits are allowed exactly (Unicode has a bunch more), you may want to use `\p{IsAlpha}` and/or `\p{IsDigit}` instead of `[A-Za-z]` and `[0-9]`, too -- though you'll also have to `use open IO => ':encoding(UTF-8)', ':std';` for that.	[reply] [d/l]
Re^2: Checking name convention by zalezny (Novice) on Feb 24, 2015 at 13:42 UTC
Thank You very much for Your efficient support! It seems that is this, what I`m looking for. :))) God bless, Zalezny	[reply]
Re: Checking name convention by Stringer (Acolyte) on Feb 24, 2015 at 15:01 UTC
You can use a regular expression to look for the pattern, and an until loop to keep prompting the user until their input matches your desired pattern: `my $os_user = '&'; #stop warnings from yelling at you print "OS username:"; until ($os_user =~ /^[A-Za-z]{3}\d{3}$/) { chomp($os_user = <>); }` [download]	[reply] [d/l]
Re^2: Checking name convention by AnomalousMonk (Archbishop) on Feb 24, 2015 at 19:15 UTC
Because no `$` end-of-string anchor is used, the `/^[A-Za-z]{3}\d{3}/` match may allow something improper: `c:\@Work\Perl\monks>perl -wMstrict -le "my $os_user = 'foo9876543210'; $os_user =~ /^[A-Za-z]{3}\d{3}/ or die qq{bad user name: '$os_user'}; print qq{'$os_user' is ok by me!}; " 'foo9876543210' is ok by me!` [download] See above for a variation that avoids this problem. See also perlre, perlrequick, and perlretut. Give a man a fish: `<%-(-(-(-<`	[reply] [d/l] [select]
Re^3: Checking name convention by Stringer (Acolyte) on Feb 24, 2015 at 20:22 UTC
Woops, you're right. Updated it with the requisite anchor.	[reply]