in reply to variable comparison

If all you are trying to do is determine the extension of a file, you can use the function
substr string, pos, [n, replacement]

which extracts and returns a substring n characters long, starting at position pos, from a given string. If pos is negative, the substring starts at the end of the string instead, so something like: 
my $ext = ".htm";
my $filename = "filename.htm";

if ($ext eq substr ($filename, -4)) {
   #whatever
}
else {
   #whatever else
}

[download]

Also, substr can be put to more interesting uses. consider:


For more information, consult Perl in a Nutshell,
ISBN 1-56592-286-7, published by O'Rielly.
Simplicus

Replies are listed 'Best First'.
RE: RE: variable comparison
by mdillon (Priest) on May 25, 2000 at 19:38 UTC
    i like the substr approach myself, although i would make the small change of using the length function instead of hard coding the length of $ext. 
    if (substr($filename, -length($ext)) eq $ext)
{
    # do stuff
}
else
{
    # do other stuff
}

    [download]
[reply]
[d/l]
      Agreed. I've been brainwashed by Redmond to assume that an
      extension is three characters long. My early DOS training
      is to blame for that. (good ol' 8.3 notation, you know?)

      Using a regex to hunt for the dot is out of the question,
      because you might have a filename "foo.bar.htm" for example.
      Of course, you could always look for the last instance of
      the . in the filename, but . . . in the interst of having
      clearer code, I like the substr approach better than the
      regex (if only this once ;-) )
[reply]
        for finding the last instance of a string in another string, you can use rindex.
[reply]

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