Re^2: Query on Perl system command

[Anonymous Monk]

When I modified

system 'echo "$filename.txt\n$filename.xls\n" | phylip';

with

qq(echo "$filename.txt\n$filename.xls\n" | phylip );

OR with

qq~echo "$filename.txt\n$filename.xls\n" | phylip ~;

I get the following error message

"Useless use of string in void context at alignment.pl line 75."

Any idea, why this is happening ? (I am newbie to perl)

I appreciate your help

[ww]

I'm a newbie to your code.

Which is / what's in "Line 75?"

[Anonymous Monk]

Oops... I copied entire error message !!

qq(echo "$filename.txt\n$filename.xls\n" | phylip );

This piece of code is in line 75

[Anonymous Monk]

If you allow me to complicate my script, The complete system command looks like this...

system 'echo "4\n6\n3\n5\n\n1\n$filename.fsmi\n5\n$filename.phb\n111\n
+1000\n4\n$filename.ph\n$filename.dst\n\n2\n" | phylip';

phylip has many options, and user have to choose the option by pressing 1 or 2 or 3 or 4 ... etc. The point of giving output file name comes after choosing many such options. When I run "phylip" program separately (by "seperately", I mean, running "phylip" outside perl script) I type 1,2 or 3...etc and press ENTER key to choose that option. When I am calling "phylip" inside perl script, I use "\n" as a substitute for ENTER key