Re: using pipes in a system() call

So here is the entire program, this is just a prototype but its just looking through the many home directories we have to find files owned by $UID, and chown's them to the new UID($NEWUID):

#!/usr/local/bin/perl

my $UID = 1202;
my $NEWUID = 51617;

my @home = ( "/home1/", "/home2/", "/home3/", "/home4/", "/home5/",
             "/home6/", "/home7/", "/home8/", "/home9/", "/home10/",
             "/home11/", "/home12/", "/home13/", "/home14/" );
my $i = 0;
foreach( @home )
  {
    opendir DH, $home[$i] or die "Cannot open $home[$i]: $!";

    foreach $dir ( readdir DH )
      {
        next if $dir eq "." or $dir eq ".." or $dir eq ".snapshot" or 
+$dir eq "TT_DB";
        print "find $home[$i]$dir -user $OUN -print | xargs -n 1 chown
+ -h $NEWUID\n";
        system("find $home[$i]$dir -user $OUN -print | xargs -n 1 chow
+n -h $NEWUID");
      }
    $i++;
  }
[download]

the output is so:

find /home1/castillo -user 1202 -print | xargs -n 1 chown -h 51617
sh: syntax error at line 1: `|' unexpected
[download]

So the command I'm giving it prints out exactly as expected, and running that by hand does work. I guess I don't understand why a | is 'unexpected'. I did try `-print \; |` but that doesn't work either.

Thanks to all who replied.

Mike C

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Re^2: using pipes in a system() call by sgifford (Prior) on Dec 07, 2005 at 20:58 UTC
With a few small changes to avoid trashing my system, and after changing `$OUN` to `$UID`, this works for me. Maybe it's something weird with your system or your shell?. What kind of system are you on? What is `$ENV{SHELL}` set to? Does `system("ls \|cat");` work? Or maybe it's an invisible character (like a carriage return) in one of your strings. Try piping the program through `cat -e` to show any nonprinting characters. A third idea is to `strace`/`truss`/`ktrace` your program, to see what it's actually running.	[reply] [d/l] [select]
Re^2: using pipes in a system() call by jfroebe (Parson) on Dec 07, 2005 at 21:03 UTC
Hi Mike, Since you are looking for files in a specified set of directories, you may want to take a look at File::Find -- no sense in reinventing the wheel ;-) Jason L. Froebe Team Sybase member No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1	[reply]