perl - how come this script works?


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# 1  
perl - how come this script works?

Code:
#!/usr/bin/perl
open (DATA, file.txt);
@array = <DATA>;
close (DATA);

open (DATA, ">$file.txt");
for (@array) {
      s/text/replace text/;
      push(@contents,$_);
}
seek(DATA, 0, 0);
print DATA (@contents);

close(DATA);

could someone please explain how this works. i've been trying for awhile now to find out how to open a file, replace some text and then save the file. i eventually found the code above.

however, as far as i knew 'push' placed an item onto the end of an already defined array, but in the code above @contents isn't defined.

what's going on?

regards,

matt
# 2  
Perl does the "array declaration" for you.
# 3  
Quote:
Originally Posted by mjays
but in the code above @contents isn't defined.
It is implicitly created for you. In this case, it is an array with no elements inside. You can always put

@contents = ();

at the top of the script to make your intent specific (I usually do this), but it is not required.

To explicitly declare it as a lexical is in fact a better practice, so that becomes

my @contents = ();

As for your posted program, it is a very simple one (I think you have stated it yourself). If you have any specific queries, feel free to follow-up.
# 4  
oh i see.

thank you all.
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