Dear all

I have a text file and some of the lines contain a trailing asterisk (they are protein sequences and * stands for a stop codon). I was trying to write a short perl script to remove (substitute with empty string) them, but I got some results I found weird. Hopefully someone could help me.

I tried this code, but it does not work. The * are still there.

while(my $line = <$in>){
    $line =~ s/\*$//;
    print $line;
    }

[download]

When I tried this code, it suddenly worked. 

while(my $line = <$in>){
    $line =~ s/\*\s$//;
    print $line;
}

[download]

I think the previous code worked because every line contains a newline character (\n). But when I replace \s with \n the code stopped working. That made me confused and made me wonder these three things:

Thanks in advance.

In reply to Removing trailing asterisk from lines with regex by Tmms

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