Shell Programming and Scripting

Hi

I need to write a Perl script that the file given as first argument of the command line that will find all occurrences of the string given as the third argument of the command line and replace with the string given as the fourth argument. Name newfound file is specified as the second argument of the command line.

I don't now how to get the atributes from comand line and how to write in the new file.

Thank you.

You can get at the arguments in Perl via the $ARGV array, like $ARGV[0], $ARGV[1], etc.

You can open a file for writing like

Code:

open(FILE, ">filename");

where the > stands for 'write', like in shell redirection.

Then you can

Code:

print FILE "some text\n";

I try this code, but it doesn't work

Code:

$FILE=$ARGV[0];


open(FILE) or die "can't open: $!";

foreach $red(<FILE>)
{
	chop ($red);
	$red =~ s/$ARGV[2]/$ARGV[3];
} > $ARGV[1];

Moderator's Comments:

Code tags for code, please.

In what way does it "not work"?

Don't try to build the program all at once if you don't know how, it won't work and you won't be able to tell why. Build it in parts, keep adding on.

Try things like

Code:

print $ARGV[0], "\n";

to see if you're getting the argument you think you are.

open() doesn't work that way. You have to give it a file name, like I showed you.

Just because there's a $FILE variable doesn't mean you've opened FILE. They really have nothing to do with each other.

> doesn't work that way either, it only works like I showed you, inside open() itself.