Multi shell/perl output problem

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

I am making a crontab parser for the whole system.
One script (run by root) grabs the list of users:

#!/usr/bin/perl

use strict;
use locale;

my (@users,$i); 


$i = 1;

open(PW,"/etc/passwd") or die "Can't open //etc//passwd: $!\n"; 
while (<PW>) {
  ($users[$i]) = (split /:/)[0];
  print "\n\n==========================================\n$users[$i]\n"
+;
  system "/usr/bin/su", $users[$i], "-c /cronme";
  $i = $i + 1;
}
[download]

The cronme script goes through a crontab file and makes
a nicely readable calendar-type listing with comments
and such. But I expect the output to be like this:

============
User1
[Calendar]

============
User2
[Calendar]

============
User3
[Calendar]
[download]

Instead I get:

============
User1
============
User2
============
User3

[Calendar]

[Calendar]

[Calendar]
[download]

Any help ?

Comment on Multi shell/perl output problem Select or Download Code

Replies are listed 'Best First'.
Re: Multi shell/perl output problem by mkmcconn (Chaplain) on Jan 19, 2002 at 04:29 UTC
You are Suffering from Buffering. mkmcconn	[reply]
Re: Multi shell/perl output problem by Kanji (Parson) on Jan 19, 2002 at 10:06 UTC
On a different note, is there any special reason why you're making an array of all the users as you go? If not, you might want to consider making use of the `getpw*` family of functions, particularly `getpwent`... `#!/usr/bin/perl -w use strict; $\|++; # disable buffering while ( my $user = getpwent ) { print "\n\n", "=" x 40, "\n$user\n"; system "/usr/bin/su", $user, "-c", "/cronme"; }` [download] --k.	[reply] [d/l]