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Shell script containing single-line Perl has empty results

I have a single line Perl that works fine on the command line:

perl -nle 'm"\w+:x:\d+:\d+:\S+:/S+:(\S+)$" and $h{$1}++; END{ print "$_: $h{$_}" foreach sort { $h{$b} <=> $h{$a} } keys %h }' /etc/textfile

I put this in a shell file called shell.sh, so the next guy won't have to copy / paste it and you can just run it:

#!/bin/sh
perl -nle 'm"\w+:x:\d+:\d+:\S+:/S+:(\S+)$" and $h{$1}++; END{ print "$_: $h{$_}" foreach sort { $h{$b} <=> $h{$a} } keys %h }' /etc/textfile

I try to run this on the command line and get no results; it just loads a new prompt without output. Does anyone see what I'm doing wrong?

Here are some system specifications:

Linux Version 2.6.32-220.13.1.el6.x86_64

(gcc version 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC)

GNU bash version 4.1.2 (1) -release (x86_64-redhat-linux-gnu)

Here is a bit from a text file:

rfink:x:140:140:rat fink:/var/lib/rfink:/sbin/nologin                                 
edible:x:16252:10001:eric idle:/users/eidle/:/bin/bash                                       
tsawyer:x:30855:10001:tom sawyer:/users/tsawyer/:/bin/bash                                
karthur:x:30886:10001:King Arthur:/users/karthur/:/bin/bash                                         
karthur:x:30886:10001:king arthur:/users/karthur/:/bin/bash                                         
jcash:x:30887:10001:john cash:/users/jcash/:/bin/bash                              
hpotter:x:30887:10001:harry potter:/users/hpotter/:/bin/bash                              
triddle:x:30956:10001:tom riddle:/users/triddle/:/bin/bash
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2 answers

Quick response

perl -nle 'm"\w+:x:\d+:\d+:[^:]+:\S+:(\S+)\s*$" and $h{$1}++;
  END{ print "$_: $h{$_}" foreach sort { $h{$b} <=> $h{$a} } keys %h }' \
  /etc/textfile

.

  • , [^:]+ .
  • .
  • \s* $, .

:

/bin/bash: 7
/sbin/nologin: 1

Perl awk,

perl -F: -lane '++$sh{$F[-1]};
  END{print "$_: $sh{$_}" for sort { $sh{$b} <=> $sh{$a} } keys %sh}' \
  /etc/textfile

, , .

perl -F: -lane '($sh = pop @F) =~ s/\s+$//; ++$sh{$sh};
  END{print "$_: $sh{$_}" for sort { $sh{$b} <=> $sh{$a} } keys %sh}' \
  /etc/textfile

, :

perl -pe 's/[^\S\n]+$//' /etc/textfile |
  perl -F: -lane 'print $F[-1]' |
    sort | uniq -c | sort -nr

, .

] ; s , .

      7 /bin/bash
      1 /sbin/nologin

script

script, vibe off daxim & rsquo; s answer —

#! /bin/sh

perl -MUser::pwent -le \
  '$_->shell && print $_->shell while $_ = getpwent' |
  sort | uniq -c | sort -nr

, 0.

don & rsquo; t /etc/passwd, script

#! /bin/sh

if [ $# -eq 0 ]; then
  echo Usage: $0 passwd-file .. 1>&2
  exit 1
fi

perl -pe 's/[^\S\n]+$//' "$@" |
  perl -lne 'm|\w+:x:\d+:\d+:[^:]+:\S+:(\S+)$| && print $1' |
    sort | uniq -c | sort -nr

, , , , . .

+3

ad-hoc regex, .

perl -MUser::pwent=getpwent -e'
    while (my $pwent = getpwent) { $h{ $pwent->shell }++; }
    END { print "$_: $h{$_}\n" for sort { $h{$b} <=> $h{$a} } keys %h }
'

reg-ex, , split, index/substr, unpack. autosplit:

perl -F: -lane'
    $h{ $F[-1] }++;
    END { print "$_: $h{$_}" for sort { $h{$b} <=> $h{$a} } keys %h }
' /etc/textfile

, .

+2

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