|
|
|
google unix.com
|
|||||||
| Forums | Register | Forum Rules | Links | Albums | FAQ | Members List | Calendar | Search | Today's Posts | Mark Forums Read |
| Shell Programming and Scripting Post questions about KSH, CSH, SH, BASH, PERL, PHP, SED, AWK and OTHER shell scripts and shell scripting languages here. |
More UNIX and Linux Forum Topics You Might Find Helpful
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Extracting lines that match string at certain position | paruthiveeran | UNIX for Dummies Questions & Answers | 5 | 06-09-2008 12:03 PM |
| Replacing Last occurance of & from a string | vivekshady | Shell Programming and Scripting | 1 | 05-13-2008 09:15 PM |
| String search - Command to find second occurance | saurabhsinha23 | UNIX for Dummies Questions & Answers | 5 | 12-06-2007 08:03 PM |
| count string occurance in a file hourly | ayhanne | UNIX for Dummies Questions & Answers | 2 | 10-13-2007 11:47 AM |
| Removing the last occurance of string | dkhanna01 | Shell Programming and Scripting | 7 | 12-28-2004 05:46 AM |
 |
Powered by 
|
|
|
LinkBack | Thread Tools | Search this Thread | Rate Thread | Display Modes |
|
|
10-24-2008
|
||||
|
||||
How can I match lines with just one occurance of a string in awk?
Hi, I'm trying to match records using awk which contain only one occurance of my string, I know how to match one or more (+) but matching only one is eluding me without developing some convoluted bit of code. I was hoping there would be some simple pattern matching thing similar to '+' but which means 'one and only one occurance of'. My matching code looks like this: Code:
$10 !~ /&| and | AND | And |\// && $11 !~ /FLAT|Flat|Apartment|APARTMENT/ && $10 ~ /MR|MISS|MRS|MS|Mr|Miss|Mrs|Ms/ {
But some records have in their name field multiple names, such as Quote:
Any help with this would be grand! The only alternative I can think of is some convoluted counting loop which goes through the name split as an array to count if any of the Mr, Mrs, MR, MRS, etc occur more than once, which sounds quite long-winded and unnecessary. |
|
10-25-2008
|
|||||
|
|||||
|
Hi. I find that such things are relatively straight-forward in perl because of the power of regular expression infrastructure. I don't know if awk has this feature as visibly as does perl, but here is a shell script that drives a small perl script: Code:
#!/bin/bash -
# @(#) s1 Demonstrate perl.
echo
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version "=o" $(_eat $0 $1) perl
set -o nounset
echo
FILE=${1-data1}
echo " Data file $FILE:"
cat $FILE
echo
echo " perl script file:"
cat p1
echo
echo " Results:"
./p1 $FILE
exit 0
Producing: Code:
% ./s1
(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash 2.05b.0
perl 5.8.4
Data file data1:
Mr Magoo
Mr Magoo mr magoo
Mr Magoo Mr Smith Miss Demeanor
Mr Smith Miss Demeanor
Miss Demeanor Miss Taken
Miss Taken
perl script file:
#!/usr/bin/perl
# @(#) p1 Demonstrate skipping of line with repeated matches.
use warnings;
use strict;
my($debug);
$debug = 0;
$debug = 1;
my($t1);
my($lines) = 0;
# Make entire line lower case to simply matches. Use captured
# string to omit lines with contain more than one match.
while ( <> ) {
chomp;
print " Working on |$_|\n";
$lines++;
$t1 = lc $_;
next if $t1 =~ /(mr|miss).*\1/;
print "$_\n";;
}
print STDERR " ( Lines read: $lines )\n";
exit(0);
Results:
Working on |Mr Magoo|
Mr Magoo
Working on |Mr Magoo mr magoo|
Working on |Mr Magoo Mr Smith Miss Demeanor|
Working on |Mr Smith Miss Demeanor|
Mr Smith Miss Demeanor
Working on |Miss Demeanor Miss Taken|
Working on |Miss Taken|
Miss Taken
( Lines read: 6 )
Best wishes ... cheers, drl |
|
10-25-2008
|
|||||
|
|||||
|
With GNU AWK: Code:
$ cat file Mr Magoo Mr Magoo mr magoo Mr Magoo Mr Smith Miss Demeanor Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken $ awk -F'm(r|iss)' 'NF==2' IGNORECASE=9 file Mr Magoo Miss Taken Or another version of drl's solution: Code:
perl -nle'!/(m(r|iss)).*\2/i&&print' file Some versions of sed: Code:
sed -nr '/(m(r|iss)).*\2/I!p' file ... I can't manage to make it work with grep. 
Last edited by radoulov; 10-25-2008 at 06:03 PM.. |
|
10-25-2008
|
||||
|
||||
|
Quote:
Code:
# cat file Mr Magoo Mr Magoo mr magoo Mr Magoo Mr Smith Miss Demeanor Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken # awk 'NF==2' file Mr Magoo Miss Taken # awk -F'm(r|iss)' 'NF==2' IGNORECASE=9 file Mr Magoo mr magoo |
|
10-25-2008
|
|||||
|
|||||
|
Quote:
Code:
$ cat file Mr Magoo A Mr Magoo mr magoo Mr Magoo Mr Smith Miss Demeanor Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken B $ awk -F'm(r|iss)' 'NF==2' IGNORECASE=9 file Mr Magoo A Miss Taken B $ nawk -F'm(r|iss)' 'NF==2' IGNORECASE=9 file Mr Magoo mr magoo Just for completeness: Code:
$ awk --version|head -1 GNU Awk 3.1.6 $ strings =nawk|grep -Fm1 version version 20070501 The problem with your second example is the case sensitive search (IGNORECASE is GNU specific): Code:
$ print 'mr
mr mr
miss
miss miss'|nawk -F'm(r|iss)' 'NF==2{print NR,$0}'
1 mr
3 miss
You may try to make it case insensitive using more verbose code 
Last edited by radoulov; 10-25-2008 at 06:38 PM.. |
|
10-25-2008
|
|||||
|
|||||
|
Hi. Quote:
Code:
#!/bin/bash -
# @(#) s1 Demonstrate perl regular expressions in grep.
echo
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version "=o" $(_eat $0 $1) grep
set -o nounset
echo
FILE=${1-data1}
echo " Data file $FILE:"
cat $FILE
echo
echo " Results:"
grep -v -i --perl-regexp '(mr).*\1' $FILE
exit 0
Producing (on openSUSE 11.0 (i586)): Code:
$ ./s2 (Versions displayed with local utility "version") Linux 2.6.25.16-0.1-pae GNU bash 3.2.39 GNU grep 2.5.2 Data file data1: Mr Magoo Mr Magoo mr magoo Mr Magoo Mr Smith Miss Demeanor Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken Results: Mr Magoo Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken cheers, drl |
|
10-26-2008
|
|||||
|
|||||
|
Quote:
thank you! It was not obvious to me that this option was needed: Code:
$ cat file Mr Magoo Mr Magoo mr magoo Mr Magoo Mr Smith Miss Demeanor Mr Smith Miss Demeanor Miss Demeanor Miss Taken Miss Taken $ grep -viP '(m|(r|iss)).*\2' file Mr Magoo Miss Taken Just an addition (I don't know how I missed that yesterday), it seems it works with ERE's too: Code:
$ grep -Evi '(m|(r|iss)).*\2' file Mr Magoo Miss Taken $ egrep -vi '(m|(r|iss)).*\2' file Mr Magoo Miss Taken Last edited by radoulov; 10-26-2008 at 08:23 AM.. |
|
| Bookmarks |
| Thread Tools | Search this Thread |
| Display Modes | Rate This Thread |
|
|
Hybrid Mode
