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Full Discussion: Unable to understand awk script.
Top Forums UNIX for Dummies Questions & Answers Unable to understand awk script. Post 302896054 by scriptor on Friday 4th of April 2014 06:01:47 AM
Old 04-04-2014
Hi Scrutinizer,

as you said the
Code:
*

means match for zero or more occurrence. that part i understand.

but when i remove one
Code:
*

(which is present in middle) in first line the o/p got changed . as compared to the one without making any change. can you please explain why ?

see below changed code

Code:
 
$ awk '
> / *\$[1-9][0-9] \.[0-9][0-9] */ { print $1,$2,$3,"*"; }
> / *\$0\.[0-9][0-9] */ { print ; }
> ' fruits1
Banana $0.89 100
Peach $0.79 65
Apple $0.99 78
 
o/p
 
Banana $0.89 100
Peach $0.79 65
Apple $0.99 78


here i feel the working of each astric is different. can you please comment on this too


below the content given in tutorial

Code:
Taking Pattern-Specific Actions
Say that you want to highlight those fruits that cost more than a dollar by putting a * at the end of the line for
those fruits. This means that you need to perform different actions depending on the pattern that was
matched for the price.
Start with the following script:
#!/bin/sh
awk '
/ *\$[1-9][0-9]*\.[0-9][0-9] */ { print $1,$2,$3,"*"; }
/ *\$0\.[0-9][0-9] */ { print ; }
' fruit_prices.txt
 

The output looks like the following:
Banana $0.89 100
Peach $0.79 65
Kiwi $1.50 22 *
Pineapple $1.29 35 *
Apple $0.99 78

thx in advance.

Scriptor
Last edited by scriptor; 04-04-2014 at 07:26 AM.. Reason: missed to add one point
 

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LEARN ABOUT CENTOS

igawk

IGAWK(1)							 Utility Commands							  IGAWK(1)

NAME

       igawk - gawk with include files

SYNOPSIS

       igawk [ all gawk options ] -f program-file [ -- ] file ...
       igawk [ all gawk options ] [ -- ] program-text file ...

DESCRIPTION

       Igawk is a simple shell script that adds the ability to have ``include files'' to gawk(1).

       AWK programs for igawk are the same as for gawk, except that, in addition, you may have lines like

	      @include getopt.awk

       in your program to include the file getopt.awk from either the current directory or one of the other directories in the search path.

OPTIONS

       See gawk(1) for a full description of the AWK language and the options that gawk supports.

EXAMPLES

       cat << EOF > test.awk
       @include getopt.awk

       BEGIN {
	    while (getopt(ARGC, ARGV, "am:q") != -1)
		 ...
       }
       EOF

       igawk -f test.awk

SEE ALSO

       gawk(1)

       Effective AWK Programming, Edition 1.0, published by the Free Software Foundation, 1995.

AUTHOR

       Arnold Robbins (arnold@skeeve.com).

Free Software Foundation					    Nov 3 1999								  IGAWK(1)
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