When you put a variable in the first section of a s/// substitution, the variable's contents are used as a pattern, not as a simple string. So, c:\top is understood as 5 characters, with the middle character being a TAB ("\t"). You can fix this by using quotemeta.

I would also add a start-of-string anchor to be safer.

You may need something like make_path from File::Path instead of mkdir when creating multiple levels of directory all at once.

Working, tested exmaple code:

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

my $dir     = 'c:\top\dir\file';
my $oldroot = 'c:\top';
my $newroot = 'c:\newtop';

my $newdir = $dir;

print "Oldroot will be used as the pattern; It is '$oldroot'\n";
print "newdir was: '$newdir'\n";
$newdir =~ s/$oldroot/$newroot/
    or warn "Can't find pattern '$oldroot' in dir string '$newdir'";
print "newdir now: '$newdir'\n\n";

my $oldroot_regex = quotemeta $oldroot;
#$oldroot_regex = '^' . $oldroot_regex; # I would do this to be safe.
print "Escaped pattern is '$oldroot_regex'\n";

print "newdir was: '$newdir'\n";
$newdir =~ s/$oldroot_regex/$newroot/
    or warn "Can't find pattern '$oldroot_regex' in dir string '$newdi
+r'";
print "newdir now: '$newdir'\n\n";

[download]
Output:
    Oldroot will be used as the pattern; It is 'c:\top'
    newdir was: 'c:\top\dir\file'
    Can't find pattern 'c:\top' in dir string 'c:\top\dir\file' at pm_
+790602_03.pl line 13.
    newdir now: 'c:\top\dir\file'

    Escaped pattern is 'c\:\\top'
    newdir was: 'c:\top\dir\file'
    newdir now: 'c:\newtop\dir\file'

[download]
By the way, you will save yourself some future headaches if you just standardize on POSIX paths (forward slashes instead of backslashes), which *do* work fine in Perl on Win32. I use $path =~ tr{\\}{/} to fix up user input.

In reply to Re: replace part of directory by Util
in thread replace part of directory by Anonymous Monk

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