UNIX for Dummies Questions & Answers

#!/usr/bin/env bash

# @(#) s1	Demonstrate join output field specifications.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
pe() { for i;do printf "%s" "$i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for i;do printf "%s" "$i";done; printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && . $C join

FILE1=${1-data1}
FILE2=${2-data2}

pl " Data file $FILE1:"
cat $FILE1

pl " Data file $FILE2:"
cat $FILE2

pl " Results from join:"
join -j 1 -o 0 1.2 0 2.2 $FILE1 $FILE2

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 5.0.7 (lenny) 
GNU bash 3.2.39
join (GNU coreutils) 6.10

-----
 Data file data1:
1 Dave
2 Mark
3 Paul

-----
 Data file data2:
1 Apple
2 Orange
3 Grapes

-----
 Results from join:
1 Dave 1 Apple
2 Mark 2 Orange
3 Paul 3 Grapes