Use the same perl script with several different variables

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# 1  
Old 10-02-2009
Use the same perl script with several different variables

I'm new to perl and have to create these files for my job. I have a script that I can run that will create the file, but I have to manually pass the variables to it. It is dumb and it takes a lot of time. I want to be able to pass the existing perl script a set of variables (the same variables with different values) over and over again, until it runs through them.

Basically, I want to keep a file with the variables:

run script with these > output to a file

run script with these > output to a file

Anyone willing to give a newbie some help?

# 2  
Old 10-02-2009
so say you put your variables in space-delimited lines in a file name 'in.txt'. The content of this file for example is:
abc def ghi
jkl mno pqr

you could invoke your script '' like this:
Code: in.txt out.txt

as you may know, in.txt is passed into the script in the default array ARGV.

inside your script, you would have something like this, then, to create file handles to open the input file, and a second arg for the output file

open FHIN,"<$ARGV[0]";
open FHOUT, ">$ARGV[1]";

then you would read the input file line by line, splitting each line on spaces into an array, to pass to your processing function for output:


# the function you will execute with your vars
sub proc_array
   # open the output filehandle
   open FHOUT, ">ARGV[1]";
   #iterate over the array you pass to the function
   foreach my $var (@_)
          # here it just prints the value and a newline
          # but you would be doing something more interesting
	  print FHOUT $var."\n"
   # close the output filehandle
   close FHOUT;

#open the file handle
open FHIN, $ARGV[0];

#iterate over each line in the file
foreach my $line (<FHIN>)
        # split the space-delimited var strings and store each var in an array
	my @vars = split(/\s/,$line);
        # pass the array to your processing function
# close the filehandle when done
close FHIN;

the output of the script in this example is:

if you want to output to multiple files, you could either pass in multiple args, or name your file with timestamps or something else programmatically.

Last edited by varontron; 10-03-2009 at 12:27 AM..
# 3  
Old 10-06-2009
ok...still need some help

I've tested this and it works, but I'm not able to put variables in my input file and have them read as variables. I'm not sure if that makes sense, but if I declare my variables in my input file, the other script doesn't recognize them as a variable, only a string.
# 4  
Old 10-06-2009
perhaps you can post your files?

If you're declaring variables in the first script and then calling the second from it, you need to use some sort of persistent memory, which is probably way overcomplicated. the second perl script has no knowledge of the memory used by it's caller.

alternatively you want to declare vars in the second script to hold the vals you need, and pass those values from the first script to it. you can do this through arguments, pipes, files, etc.
# 5  
Old 10-06-2009
May be you'd like to set and use envinonment variable?
bash-2.05$ export aaa='bla bla bla'
bash-2.05$ perl -e 'print "$ENV{aaa}\n"'
bla bla bla

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