in reply to replacing text in multiple files

If you have (a version of) the unix/linux "cat" utility, you can use the "diamond" operator as suggested by Eliya's initial reply, and pipe the concatenated set of files to your script's STDIN -- for that matter, you can also just print to STDOUT, and use redirection to a file on the command line: 
cat *.log | your_script > modified.log-data

[download]
With that sort of usage, you don't need to worry about opening or closing files in your code; just read, do stuff, and print: 
#!/usr/bin/perl

use strict;

while (<>) {
    # do stuff here, then...
    print;
}

[download]

Replies are listed 'Best First'.
Re^2: replacing text in multiple files
by Eliya (Vicar) on Apr 14, 2012 at 04:43 UTC
    cat *.log | your_script > modified.log-data

    Why use cat when Perl can do it all by itself?  With the added benefit of $ARGV letting you know which file you're working on, and being able to do in-place edits via -i / $^I:

    $ cat *.log
bar1
bar2
bar3
baz1
baz2
baz3
foo1
foo2
foo3

$ perl -ne 'print "$ARGV: $_"' *.log
bar.log: bar1
bar.log: bar2
bar.log: bar3
baz.log: baz1
baz.log: baz2
baz.log: baz3
foo.log: foo1
foo.log: foo2
foo.log: foo3

$ cat *.log | perl -ne 'print "$ARGV: $_"'
-: bar1
-: bar2
-: bar3
-: baz1
-: baz2
-: baz3
-: foo1
-: foo2
-: foo3

$ perl -i -ne 'print ucfirst $_' *.log
$ cat *.log
Bar1
Bar2
Bar3
Baz1
Baz2
Baz3
Foo1
Foo2
Foo3

    [download]

    (note to the OP:  -n is the short "command line" version of saying while (<>) { ... } — see perl -h )

[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom