Problem with Parentheses

jjoyce has asked for the wisdom of the Perl Monks concerning the following question:

This script executes in my Linux without problem:

find . -type f $ -perm -0020 -o -perm -0004 -o -perm -0002 -o -perm -0001 -o -perm -1000 $ -ls

However, when I try to embedded it on a Perl code:

 #!/usr/bin/perl
my $out = "output.txt";
open (MYFILE,"> $out");
print MYFILE `find . -type f \( -perm -0020 -o -perm -0004 -o -perm -0
+002 -o -perm -0001 -o -perm -1000 \) -ls`;
[download]

I receive the following error message:

sh: -c: line 0: syntax error near unexpected token `(' sh: -c: line 0: `find . -type f /( -perm -0020 -o -perm -0004 -o -perm -0002 -o -perm -0001 -o -perm -1000 /) -ls'

How can I fix the above code?

Comment on Problem with Parentheses Select or Download Code

Replies are listed 'Best First'.
Re: Problem with Parentheses by choroba (Cardinal) on Aug 21, 2012 at 21:12 UTC
Double-escape the parentheses: print MYFILE `find . -type f \$ -perm -0020 -o -perm -0004 -o -perm - +0002 -o -perm -0001 -o -perm -1000 \$ -ls`; [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re^2: Problem with Parentheses by jjoyce (Initiate) on Aug 21, 2012 at 21:30 UTC
Thank you for your help, this solves my problem.	[reply]
Re: Problem with Parentheses by toolic (Bishop) on Aug 21, 2012 at 21:11 UTC
This avoids the error for me: my $cmd = 'find . -type f $ -perm -0020 -o -perm -0004 -o -perm -0002 + -o -perm -0001 -o -perm -1000 $ -ls'; my $out = "output.txt"; open (MYFILE,"> $out"); print MYFILE `$cmd`; [download] See also: File::Find	[reply] [d/l]
Re: Problem with Parentheses by kcott (Archbishop) on Aug 21, 2012 at 21:21 UTC
The code you show has backslashes (`$` and `$`) but the error message shows forward slashes (`/(` and `/)`). Regardless, the code you need has two backslashes (in each position): $ perl -Mstrict -Mwarnings -e ' print `find . -type f \$ -perm -0020 -o -perm -0004 -o -perm -0002 -o + -perm -0001 -o -perm -1000 \$ -ls`;' ... ls listing here ... [download] -- Ken	[reply] [d/l] [select]
Re: Problem with Parentheses by james2vegas (Chaplain) on Aug 22, 2012 at 00:44 UTC
Also worth noting, you can use File::Find to duplicate this functionality without running a separate process. Running `find2perl . -type f $ -perm -0020 -o -perm -0004 -o -perm -0002 -o -perm -0001 -o -perm -1000 $ -ls` returns this equivalent Perl code (find2perl here): Read more... (3 kB) Obviously this code could be optimised.	[reply] [d/l] [select]