Formatting output

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

For some reason this script doesnt always work on some unix systems. Any changes I could make to this to make it work better?

#!/usr/local/bin/perl
open (INPUT, "< /etc/passwd");
while(<INPUT>) {

($col1, undef, undef, undef, $col5, undef) = split(/:/, $_);
#undef are blank fields here

write();
}


format STDOUT_TOP =
Name                  ID
----                  --
.

format STDOUT =
@<<<<<<<<<<<<<<       @<<<<<<<<<<<<<<<
$col1, $col5
.
[download]

Comment on Formatting output Download Code

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Re: Formatting output by cjf (Parson) on Jun 13, 2002 at 12:15 UTC
chomp the input from /etc/passwd to remove the newlines, splitting into an array is much cleaner in my opinion. Checking your open calls and using strict and warnings is also good practice. `#!/usr/bin/perl -w use strict; open INPUT, "</etc/passwd" or die "Can't open file #!\n"; my @lines; while (<INPUT>) { chomp; @lines = split /:/; write(); } format STDOUT_TOP = NAME ID ---- -- . format STDOUT = @<<<<<<<<<<<<<< @<<<<<<<<<<<<<<<<<< $lines[0], $lines[4] .` [download] Also, what systems is it failing on, what errors does it give?.	[reply] [d/l]
Re: Re: Formatting output by Anonymous Monk on Jun 13, 2002 at 13:19 UTC
I need to find out what system it is on. Thanks for the input and I will try it out when the system is back up.	[reply]
Re: Formatting output by jmcnamara (Monsignor) on Jun 13, 2002 at 12:17 UTC
It worked for me on a Linux and a Solaris system. What happens when it doesn't work. The following does something similar as a one liner: `perl -F: -ane 'printf "%-20.20s\t%-20.20s\n", $F[0], $F[4]' /etc/passwd` Or following Zaxo's getpwent suggestion: `perl -e 'printf "%-14.14s\t%-14.14s\n", $a[0], $a[6] while @a = getpwent()'` -- John.	[reply] [d/l] [select]
Re: Formatting output by Zaxo (Archbishop) on Jun 13, 2002 at 12:36 UTC
This has nothing to do with your output format question, but I'd suggest a look at getpwent. Output format can also be done with printf and sprintf, which may be more comfortable for C programmers. After Compline, Zaxo	[reply]
Re: Formatting output by Abigail-II (Bishop) on Jun 13, 2002 at 12:16 UTC
Please define "doesnt always work". If I run the program, I do get output. Nothing strange happens. What do you expect as output, and what happens? Abigail	[reply]