NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/comp/unix/question/10256

Text File | 1992-08-21 | 1.7 KB | 50 lines

Newsgroups: comp.unix.questions
Path: sparky!uunet!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!news.acns.nwu.edu!casbah.acns.nwu.edu!navarra
From: [e-mail] (John Navarra)
Subject: Passing shell variable in if statement in awk
Message-ID: <[e-mail]>
Sender: [e-mail] (Usenet on news.acns)
Organization: Northwestern University, Evanston Illinois.
Date: Fri, 21 Aug 1992 11:45:03 GMT
Lines: 39

I have written the following awk script called extract which prints
out the lines of text in a file between pattern1 and pattern2 where
the pattern is specified on the command line. Here is the script:

#!/bin/sh
# extract [-n] pattern1 pattern2 < filename
# awk script which prints out block of information between pattern1 and
# pattern2 in a file. If pattern2 is not specified, it prints from the
# first pattern to the end of file. The -n option will print out the
# line numbers of the file between the two patterns.

if [ "$1" = "-n" ]
   then  shownumbers=yes
     shift; pattern1=$1; pattern2=${2:-NF}
   else
         pattern1=$1; pattern2=${2:-NF}
fi

awk '
/'"$pattern1"'/,/'"$pattern2"'/ {
    if ( '"$shownumbers"' )
    printf("[%d] \t %s \n", NR, $0)
    else
    printf("%s\n",$0)
}' -

    I am having trouble passing the 'shownumbers' variable into the
awk script. I want to test if it exists or not. If extract is called with
the -n option, the line numbers for the file are printed in addition to
the line themselves (like grep -n ). If the -n is called, I set shownumbers
to yes. However, it does not pass through to the awk script for some
reason that I can't understand. What am I doing wrong?

-tms

--
From the Lab of the MaD ScIenTiST:

[e-mail]