Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Need bash script to use a sed command as a variable
Top Forums Shell Programming and Scripting Need bash script to use a sed command as a variable Post 303038031 by Scrutinizer on Thursday 22nd of August 2019 01:53:54 AM
Old 08-22-2019
Note that with standard sed (non-GNU) there needs to be a ; before the trailing }:
Code:
ip=$(sed -n '/inet */{s///p;q;}' config.boot)

or we can avoid the braces by using negation style:
Code:
ip=$(sed '/inet */!d; s///; q' config.boot)

--
Alternatively we can avoid the sub shell / external command altogether with just standard shell:
Code:
until [ "$inet" = inet ]; do
  read inet ip
done < config.boot

--
Note also that these are all naive approaches without knowing what the format of config.boot looks like. Also, if the are more inet configs in the same file, these will only pick the first one indiscriminately.
Last edited by Scrutinizer; 08-22-2019 at 03:16 AM..
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

BASH -- sed -- variable

Hi, I'm new at bash scripting -- can anyone here help me about the sed command? I need to be able to edit and or delete a text from an outside file ie file.txt -- I'm passing a variable and not a string I was thinking of something like echo -n "What do you want to edit?: " read edit sed... (1 Reply)
Discussion started by: Imajean
1 Replies

2. Shell Programming and Scripting

passing variable from bash to perl from bash script

Hi All, I need to pass a variable to perl script from bash script, where in perl i am using if condition. Here is the cmd what i am using in perl FROM_DATE="06/05/2008" TO_DATE="07/05/2008" "perl -ne ' print if ( $_ >="$FROM_DATE" && $_ <= "$TO_DATE" ) ' filename" filename has... (10 Replies)
Discussion started by: arsidh
10 Replies

3. Shell Programming and Scripting

Special characters in a bash variable in sed

Hello, I am trying the following: echo __CHANGEME__ >> testfile VAR1="&&&" sed -i "s|__CHANGEME__|${VAR1}|" testfile cat testfile This results in testfile containing __CHANGEME____CHANGEME____CHANGEME__ Whereas I want it to result in &&& I understand that if VAR1="\&\&\&" then... (3 Replies)
Discussion started by: linuxnewbeee
3 Replies

4. Shell Programming and Scripting

Insert a line including Variable & Carriage Return / sed command as Variable

I want to instert Category:XXXXX into the 2. line something like this should work, but I have somewhere the wrong sytanx. something with the linebreak goes wrong: sed "2i\\${n}Category:$cat\n" Sample: Titel Blahh Blahh abllk sdhsd sjdhf Blahh Blah Blahh Blahh Should look like... (2 Replies)
Discussion started by: lowmaster
2 Replies

5. UNIX for Dummies Questions & Answers

sed insert command and variable expansion/command substitution

I know this script is crummy, but I was just messing around.. how do I get sed's insert command to allow variable expansion to show the filename? #!/bin/bash filename=`echo $0` /usr/bin/sed '/#include/ { i\ the filename is `$filename` }' $1 exit 0 (8 Replies)
Discussion started by: glev2005
8 Replies

6. Shell Programming and Scripting

bash variable (set via awk+sed) not working as expected

Hi! Been working on a script and I've been having a problem. I've finally narrowed it down to this variable I'm setting: servername=$(awk -v FS=\/ '{ print $7 } blah.txt | sed 's\/./-/g' | awk -v FS=\- '{print $1}')" This will essentially pare down a line like this: ... (7 Replies)
Discussion started by: creativedynamo
7 Replies

7. Shell Programming and Scripting

In bash script, how to assign output of a command to a variable while keeping tabs?

Hi, wondering if it's been asked before but didn't find matches from google. Basically I have this line: myvar=$(echo -e "a\tb") Now somehow the '\t' from the echo output gets replaced with white space and then stored in $myvar. It creates a problem for me later to use tab as delimiter to do... (2 Replies)
Discussion started by: birddie
2 Replies

8. Shell Programming and Scripting

Bash script set command to a variable

Hi, Will following set up work in bash script? I've got errors if assigning following binary command to a variable. But on the other hand, COMMAND="ls" works. Any explanation please? How can I assign binary command to a variable COMMAND then I can just call ${COMMAND}? COMMAND="rsync"... (3 Replies)
Discussion started by: hce
3 Replies

9. Shell Programming and Scripting

sed command not accepting variable in shell script

I am using a shell script in fedora linux. While calling to the shell I am also passing an argument (var1=0.77) like shown below sh gossip.sh var1=0.77 in the shell following command is written (which doesn't work) sed - i -e 's@prob=@prob="$var1";//@g' file.txt Actually i want the... (7 Replies)
Discussion started by: Fakhar Hassan
7 Replies

10. Shell Programming and Scripting

Executing sed command inside a bash script

I want to run commands inside a bash script. An example is I want to pass the command in a string as regexp as an argument to the script, then run sed on the bash variable sed.sh regexp sed.sh "-i \"s/<p>//g\"" then call sed "$regexp" $fl (3 Replies)
Discussion started by: Kangol
3 Replies

LEARN ABOUT DEBIAN

fixnt

fixnt(1)							      Debian								  fixnt(1)

NAME

       fixnt - Filter for the Windows NT postscript printer driver.

SYNOPSIS

       fixnt < BADFILE.ps > GOODFILE.ps

DESCRIPTION

       The  Windows  NT  postscript  driver has a tendency to make broken postscript files, that are incompatible with psutils.  fixnt is a filter
       that fixes these problems, allowing the use of psnup(1).

       The filter takes the broken postscript file on stdin, and outputs a fixed postscript file on stdout.  It has no other form  for	invocation
       and takes no options on the command-line.

OPTIONS

       fixnt  takes no options.

BUGS

       fixnt does not check for NTPSOct94.  For a workaround, use a sed(1) command to replace 'NTPSOct94' with 'NTPSOct95', like so:
	      sed 's/NTPSOct94/NTPSOct95/g'
       This is particularly important for Windows NT 3.5 users.

AUTHOR

       fixnt   was   written   by   Holger   Bauer   <Holger.Bauer@topmail.de>,  Michael  Rath	<rath@itsm.uni-stuttgart.de>,  and  Akim  Demaille
       <demaille@inf.enst.fr>.

REPORTING BUGS

       Report bugs to the Authors, but avoid sending large postscript files.

       Patches are always welcome; send to <bauer@itsm.uni-stuttgart.de>.

SEE ALSO

       psnup(1), sed(1)

a2ps								   February 2003							  fixnt(1)
All times are GMT -4. The time now is 04:06 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy