Re: general perl question

If your program is not being run on the command line you could use code similar to this.

my $filename = 'foo.txt';

open IN, "< $filename" or die "Can't open $filename: $!\n";
open OUT, "> $filename.bak" or die "Can't write to $filename: $!\n";
while (<IN>) {
  s/foo/blah/g;
  print OUT $_;
}
close IN; close OUT;
rename "$filename.bak", $filename;
[download]

However this code is only the barest code that will work, and should probably not be used without file locks and other sanity checks.

Comment on Re: general perl question Download Code

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Re: Re: converting files in place by petdance (Parson) on Apr 24, 2001 at 17:37 UTC
The flags work without the command line, too. The following will convert any files specified on the command line to all caps. `#!/usr/bin/perl -w -i.bak -p $_ = uc;` [download] In fact, there was an Obfuscated Perl contest entry a while back that does DOS-to-Unix conversions using only command line switches on the shebang line. xoxo, Andy # Andy Lester http://www.petdance.com AIM:petdance %_=split';','.; Perl ;@;st a;m;ker;p;not;o;hac;t;her;y;ju'; print map $_{$_}, split //, 'andy@petdance.com'	[reply] [d/l]
Re: Re: Re: converting files in place by repson (Chaplain) on Apr 25, 2001 at 07:31 UTC
What I meant was that my code can be dropped in the middle of a program, while to use the switches in the middle of a program you would have to spawn a new perl with those switches. `#!/usr/bin/perl -w ..... system(q#perl -i.bak -p -e '$_ = uc'#); .....` [download]	[reply] [d/l]