Shell Programming and Scripting

#!/usr/bin/env bash

# @(#) s1	Demonstrate false positive for replicated items.

# Infrastructure details, environment, commands for forum posts. 
set +o nounset
LC_ALL=C ; LANG=C ; export LC_ALL LANG
echo ; echo "Environment: LC_ALL = $LC_ALL, LANG = $LANG"
echo "(Versions displayed with local utility \"version\")"
c=$( ps | grep $$ | awk '{print $NF}' )
version >/dev/null 2>&1 && s=$(_eat $0 $1) || s=""
[ "$c" = "$s" ] && p="$s" || p="$c"
version >/dev/null 2>&1 && version "=o" $p specimen sort uniq
set -o nounset

# If not available, replace "specimen" with "more data?|cat"
echo 
specimen data1 data2

echo " Results, expecting \"g\", not really common:"
sort data1 data2 | 
uniq -d

exit 0

% ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 2.6.26-2-amd64, x86_64
Distribution        : Debian GNU/Linux 5.0 
GNU bash 3.2.39
specimen (local) 1.3
sort (GNU coreutils) 6.10
uniq (GNU coreutils) 6.10

Whole: 3 of 3 lines in data1
g
a
g

Whole: 3 of 3 lines in data2
a
m
b

 Results, expecting "g", not really common:
a
g