regexstringperlbash

How to append a RANDOM string to all occurrences of another string in file

I'm trying to write a bash script that would modify all occurrences of a certain string in a file.

I have a file with a bunch of text, in which urls occur. All urls are in the following format:http://example.com/JB007 (that's example.com/, followed by 4 OR 5 alphanumeric characters).

What I'd like do is append a string to all urls. I managed (with the help of user Dan Fego) to get this done with sed, but it only works by appending a static string.

What I'm looking for is a way to append a different string to each occurrence. Let's say I have a function generatestring that echoes a different string every time. I'd like to append a different generated string to each url. http://example.com/JB007 would become http://example.com/JB007?GeneratedString1 and so on.

Does anyone know if this can be done? I've been told that perl is the way to go, but I have zero experience with perl. That's why I'm asking here.

Thanks in advance for any help.

Solution

  • If the URLs aren't alone in each line, you can do:

    #!/usr/bin/perl
use strict;
use warnings;

sub generate {
    my $i = shift;
    return "GeneratedString$i";
}
my $i = 0;
while(my $line = <>) {
    $line =~ s~(http://\S+)~$1 . "?" . &generate($i++)~eg;
    print $line;
}

    usage:

    test.pl file_to__modify

    output:

    http://example.com/abc23?GeneratedString1
http://example.com/JB007?GeneratedString2