Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Awk variable replacement
Top Forums Shell Programming and Scripting Awk variable replacement Post 302134343 by iAm4Free on Thursday 30th of August 2007 11:14:39 AM
Old 08-30-2007
Quote:
Originally Posted by robotronic
Actually, the single quotes are making the difference, not the double ones:

Code:
awk -F'|' '$1~/'"$1"'/{ code... }'

All the awk code is enclosed in single quotes, when you want to "break" the awk code because you need the value held by an external shell environment variable, you simply close your code with a quote and reopen it (with another quote) when you've finished the external variable evaluation.

Putting double quotes around a shell variable is only a good scripting practice (so you avoid possible problem with null values, etc...).
Thanks its very clear explanation!
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

variable replacement

hi all , i want a command that interacts with the input of a user . i.e. i want it to serch a file for the first occurance of a variable and replace the value that is after the equal sign . for example : my file contains a varible that is $HOME=/home i want to search for variable $HOME... (4 Replies)
Discussion started by: ppass
4 Replies

2. Shell Programming and Scripting

AWK String replacement

I have an xml file with following tags <NewTag>value123</xyz> <NewTag>value321</abcd> I have to replace the values in between the tags with some value ( VAL1/VAL2) but the thing the ending tag can be any thing, for this i need a awk command currently i am using this but it... (5 Replies)
Discussion started by: subin_bala
5 Replies

3. Shell Programming and Scripting

Awk replacement

Hi all, I need help in replacing awk with sed for the below. 1 ) cat list | awk -F" |," '/MATH/ {sub(/]*/,"",$3); print $3}' Eg: file : list Sno Subno Name 1 SUB1 ENG 2 SUB2 MATH 2) Eg:result Total No of Students: 2 Sno ID Sub ------------------ 1 ... (3 Replies)
Discussion started by: priyam
3 Replies

4. Shell Programming and Scripting

awk replacement problem

hi i am using awk for first time so i am having issue is it the correct way of using Y here is variable which i fetch using grep from file awk -v X={$Y} { if ($0 ~ /X/ ) { sub (out.*/,"out1",$0) } print 0 }, filename > temp when i look into temp file i dont see any replacement... (9 Replies)
Discussion started by: xyzstar
9 Replies

5. Shell Programming and Scripting

Awk replacement problem

Hello everyone, I have a problem with awk replacement... I need to replace "|\n" for "\n" I tried thisawk '{ sub(/\|\\n/, "\\n"); print }' but it seems like it doesn't work properly. Can anyone help with that? (4 Replies)
Discussion started by: 1tempus1
4 Replies

6. Shell Programming and Scripting

awk's gsub variable in replacement

I been trying to figure out how to use element of array as a replacement pattern. This works as I expected: $ echo "one two three" | awk '{ gsub(/wo/,"_BEG_&_END_",$2); print }' one t_BEG_wo_END_ three $ echo "one two three" | awk '{ tmp="foo"; gsub(/wo/,"_BEG_" tmp "_END_",$2);... (5 Replies)
Discussion started by: mirni
5 Replies

7. Shell Programming and Scripting

sed replacement in file when line is in a variable

Hi, I have a file where I want to replace the 15th field separated by comma, only on specific lines matching lots of different conditions. I have managed to read the file line by line, within the loop my line is held in a variable called $line I assume this will be using sed (maybe... (5 Replies)
Discussion started by: jpt123
5 Replies

8. Shell Programming and Scripting

Sed:- Supported variable replacement after string match?

Hi All, I am trying to replace the variable in the file after the particular match string. It is being replaced if i hardcode the value and with use of "&" with sed. sed -e "s/URL./& http:\\localhost:7223/g" But when am trying to pass the variable it is failing. I tried multiple... (9 Replies)
Discussion started by: sharsour
9 Replies

9. Shell Programming and Scripting

sed - replacement file path with variable - Escaping / character

Hi,, I have the line below in a file: $!VarSet |LFDSFN1| = '"E:\APC\Trials\20140705_427_Prototype Trial\Data\T4_20140705_Trial_Cycle_Data_13_T_Norm.txt" "VERSION=100 FILEEXT=\"*.txt\" FILEDESC=\"General Text\" "+""+"TITLE{SEARCH=NONE NAME=\"New Dataset\" LINE=1I want to write a script to change... (2 Replies)
Discussion started by: carlr
2 Replies

10. Shell Programming and Scripting

Replacement of variable by their content in a file

Dear all, I have a "SQL request" in a file: that request include different "host variable" and I would like to substitute the different "host variable" by their respective content before executing the request. For example: $ echo $SHELL /bin/bash $ cat dae2.txt DELETE FROM ... (11 Replies)
Discussion started by: dae
11 Replies

LEARN ABOUT DEBIAN

gchem3d

GCHEM3D(1)						       gnome-chemistry-utils							GCHEM3D(1)

NAME

       gchem3d - a small chemical viewer application

SYNOPSIS

       gchem3d [OPTION(S)...] [FILE...]

DESCRIPTION

       gchem3d is a small chemical viewer application, which can show several chemical file formats.

OPTIONS

       The following options are accepted:

       -b COLOR, --bgcolor=COLOR
	   Use the given color as background color.  COLOR can be one of "black" (default), "white", "#rrggbb" (don't forget to escape the "#"
	   character in the shell).

       -d MODEL, --display3d=MODEL
	   Choose how molecules are displayed.	MODEL can be one of "BallnStick" (default), "SpaceFill".

       -?, --help
	   Show application help options.

       --help-all, --help-*
	   Print all or just a group of help options. These options are not documented here. Instead see gtk-options(7) and gnome-options(7).

       -v, --version
	   Print gchem3d version information.

SEE ALSO

       gnome-options(7), gtk-options(7)

AUTHORS

       Jean Brefort <jean.brefort@normalesup.org>
	   Program author.

       Daniel Leidert <daniel.leidert@wgdd.de>
	   Manpage author.

COPYRIGHT

       Copyright (C) 2002-2007 Jean Brefort
       Copyright (C) 2004-2007 Daniel Leidert

       Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 or any
       later version published by the Free Software Foundation.

gcu 0.12				      $Date: 2009-03-19 10:53:47 +0100 (jeu. 19 mars 2009) $					GCHEM3D(1)
All times are GMT -4. The time now is 07:28 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy