Dear monks, I am using php for making an webserver. since i know a little of perl compared to PHP, the values which is on the php page is passed to a perl program. To make things easier, i am using unix system command. For example, to search an input ID, i use unix grep command. Since, i also need the sequence of the given ID, my program looks like this.

file name1:seq.txt
-------------------
>ID_101
AGCTGAGTAGACTGA
>ID_102
CGATGCTAGCTAGCTACAT
>ID_103
ATCTTATCTTTTTATACC

file name2:seq_updated.txt
--------------------------
>ID_104
AATAGCTAGAAGGA
>ID_105
AGATCGACTGAA
>ID_106
ACTAGCTACGATATATTATATATAT

my php page:
-----------
$foo="ID_106" //ID to be searched.
$cmd="perl split.pl $foo";
echo exec($cmd);

my perl program:
---------------
$bar=$ARGV[0];
print exec("grep -h -A 1 $bar *.txt");
[download]

My doubts: Why am i not able to store the exec command in a scalar or array variable and then print it. It doesnt work that way, and it works only if i print it directly. I need to save it to a variable because, i need to split the sequence line into 5 characters per line.

what i was planning to do with the variable is this:
----------------------------------------------------
foreach $str(@array){
    if($str=~/\w+/){@strs=split(//,$str);
    for($i=1;$i<=scalar(@strs);$i++){
        print "$strs[$i] ";
        if($i%5==0){print"\n";}            
    }
  }
}
}

this is how my webpage result should look like:
-----------------------------------------------
>ID_106
ACTAG
CTACG
ATATA
TTATA
TATAT
[download]

well, am i making things complicated? Can i use unix one liner system command to print 5 characters per line when i grep the ID? Please guide. Thank you.