awk variables

[BradC78]

Hello,

I'm trying to use a variable in awk, but can't get it to work. I've researched online, but all the examples I can find point to exactly how I'm doing it. Anyone know what I'm doing wrong here?

It seems like this script should print the same info twice:

echo "TEST1"
awk '/Doctor Ian/' BradsTempFile
echo "TEST2"
awk -v pat="Doctor Ian" '/pat/' BradsTempFile

However, this is the output:

$ ./TEST
TEST1
Doctor Ian - 04 2004
Doctor Ian - 06 2004
TEST2
$

Thanks for your help!

[drl]

Hi.

How could the same syntax be used for constants and variables? It couldn't. Consider:

#!/usr/bin/env bash

# @(#) s1       Demonstrate awk matching with variable.

echo
set +o nounset
LC_ALL=C ; LANG=C ; export LC_ALL LANG
echo "Environment: LC_ALL = $LC_ALL, LANG = $LANG"
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version "=o" $(_eat $0 $1) awk
set -o nounset
echo

FILE=${1-data1}

echo " Data file $FILE:"
cat $FILE

echo
echo " Results for constant:"
awk '/pit/' $FILE

PATTERN="pot"
echo
echo " Results for shell variable (expect failure):"
awk -v variable="$PATTERN" "/variable/" $FILE

PATTERN="pet"
echo
echo " Results for shell variable with matching operator:"
awk -v variable="$PATTERN" '$0 ~ variable' $FILE

exit 0

Producing:

% ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 2.6.11-x1, i686
Distribution        : Xandros Desktop 3.0.3 Business
GNU bash 2.05b.0
GNU Awk 3.1.4

 Data file data1:
pat
pet
pit
pot

 Results for constant:
pit

 Results for shell variable (expect failure):

 Results for shell variable with matching operator:
pet

In addition to experimenting with short awk codes, I usually use Robbins' Effective AWK Programming, possibly available on-line as well as printed, and also O'Reilly's sed & awk.

Best wishes ... cheers, drl

[BradC78]

Thanks!!! This is exactly the info I was looking for. Thank you very much!