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text modification

text modification

text modification


I have a script that replaces the french accented caracters
by their html entities. I works great. I would like to improve it. I would like it to take the file name from the command line, back-up that file to whatever.bak and then modify the file and write it out to the original name.

How would I do that. How would I make my script back-up the file and then rewrite it with the modified text?


RE: text modification

this is what i would do:

$file = shift || die "no input file\n";
$filebak = $file . ".bak";

open(FILE, "$file") || die;
@file = <FILE>;

open(BACK, ">$filebak") || die;
    print BACK $_;

open(FILE, "$file") || die;
    print FILE $_;

or you could just use system() or `` to copy the file to filename.bak before you modify it.

RE: text modification

Thanks Luciddream,

I appreciate your input but I went a different route:

#!/usr/bin/perl -w
$infile = shift || die;
$outfile = $infile . ".NEW";
open(IN,$infile) || die;
open(OUT,">$outfile") || die;
while(<IN>) {
    print OUT $_;

I think it is simpler. But maybe you can help me out an other way. Can you tell me, simply, what is the difference between s/// and tr/// ?

Thank you

RE: text modification

s/// does replacement. tr/// does translation..

with tr you can translate a range of characters to another range for example:


translates every a to an e, every b to an f, every c to a g, and every d to an h.

with s you can only replace like this:


replaces every instance of joe with dave.

RE: text modification

Ok Luciddream, I think I got that (maybe... english not being my 'forte'...).

If I can pick your brain some more:

1. how could I tell my script to process every file with a given extension (say .htm) in a directory?

I would like to give a path as the argument and have the script process each .htm file in that directory. Could I specify more than one extension? The first argument would be the directory and the second argument a LIST of extensions.

2. If in the script I change & to $#38; (s/&/$#38;/g) and also change é to $#233; (s/é/$#233;/g) how can I prevent the first command to change the & in the output of the second command? (I used $ because you'd see s/&/&/g if I did not)


Vieux motard que jamais...

RE: text modification


$dir = shift;
$exts = shift;

@ext = split(',', $exts);

chdir "$dir";
@files = glob('*');

foreach $file (@files)
    foreach $ext (@ext)
        ($filename, $fileext) = split('.', $file);
        if($fileext eq $ext)
            push(@good_files, $file);

#@good_files now holds all of the files you want to modify.

foreach $file (@good_files)
    open(FILE, "$file") || die;
    @lines = <FILE>;
    open(FILE, ">$file) || die;
    print FILE @lines;

i'm not sure what you mean in the regex's but, that's how i would do it. there's also a way to open directories like filehandles. i don't recall off the top of my head how to do this but i'm sure it isn't hard to find out.

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