Why did you change my line:

my @l = `ls -1b`;

to:

my @l = system(`ls -1b`);

? Mine runs the ls command in a subshell and returns the results to the @l array, one line per array element. Yours runs ls in a subshell and captures the output, but then passes that output to system, which tries to run that in another sub-process, passing the return value of that sub-process to @l, making it the first (and only) element. Odds are very good that a listing of the files in your directory doesn't make a valid system command (and could possibly make a harmful one), so the return value is an error number, in this case, -1, 'failed to execute'.

See perlipc and other docs on the difference between system and backticks, as well as other ways to run a sub-process and capture the output, like opening a pipe:

open my $pipe, '-|', 'ls -1b' or die $!;
while(<$pipe>){
  chomp;
  say qq| <tag attr='value'>$_</tag> |;
}
close $pipe;

[download]

There are a lot of different ways to do this. Perl isn't called a glue language for nothing. But some are usually better than others, depending on the circumstances.

Aaron B.
Available for small or large Perl jobs; see my home node.

In reply to Re^3: Handling the output of a system command -- how to best manage? by aaron_baugher
in thread Handling the output of a system command -- how to best manage? by taint

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