Hey all I have a pretty simple question. I am trying to replace a line in a file that is being processed. See the code below for a better understanding.

#!/usr/bin/perl

while (my $line=<>) {
    my ($blah,$blah2,$bla,$time,$blah3)=split(/:/,$line);

    if ($blah eq "test") {
        $time="UNDEF";
        # Replace line in same file.
    }
}

[download]
I know, a very simple example, but I think it gets the idea across. Rather than opening and writing to a new file, I just want to replace the line in the file that we are working with. I want to update the $time lets say. See below for a BEFORE/AFTER example.

BEFORE: "test:bob:jones:04/20/09:john",
AFTER: "test:bob:jones:UNDEF:john"

UPDATE: I am not looking to do this for a file at command line. I am looking to do this within my code for any file given to the script. I can do it with a system call to sed (i.e., system("sed \"s/$line/$blah:$blah2:$bla:$time:$blah3/\" FILE > /tmp/file; mv /tmp/file FILE); ), however, that is not something that I wish to do, and I know that there is a far easier way to do this without system calls.

In reply to Replace current line in while loop by walkingthecow

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