OPEN and WRITE a Data File in Perl

The single right arrow means overwrite the contents of the file places.txt

open(DA, ">places.txt");
print DA "I see London\n";
close(DA);

-The word DA is called a Filehandle. Always use ALL CAPS for filehandles. The DA could be pretty much anything you like except STDIN and STDOUT, which are reserved for other things.
-Use full or relative path if places.txt is in different directory.

The two right arrows below mean add to the contents of the file places.txt

open(DA, ">>places.txt");
print DA "I see London\n";
close(DA);


NOTES:
-For our Copy and Paste Code below, I previously created a directory named citydata. This directory will likely have to be chmoded 777 to be written to.
-The two vertical bars mean "or". In this instance, open file "or" print "Can't Open blablabla".
-the "\n" adds a UNIX newline to the end of our sentence.

Copy and Paste Perl Code:

#!/usr/bin/perl

print "Content-type:text/html\n\n";

open(DA, ">citydata/places.txt") || print "Can't Open File. Try chmod 777 citydata directory<br><br>";
print DA "I see London\n";
close(DA);

open(DA, "<citydata/places.txt");
@da=<DA>;
close(DA);

print @da;

exit;

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