Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

How to store the return value of a command into a variable?

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting How to store the return value of a command into a variable?
# 1  
Old 10-31-2011
Computer How to store the return value of a command into a variable?
I want to store the return value of

grep -c string filename

into a variable, say count. How do I do that?

For example if grep -c "string" "filename" shows 0 on executing it in the sh shell then I want to store this 0 in a variable. Is it possible? Smilie
# 2  
Old 10-31-2011
There are two ways:
Code:
count=`grep -c "string" "filename"`
count=$(grep -c "string" "filename")

# 3  
Old 10-31-2011
try this
var=`grep -c string filename` or var=$(grep -c string filename)
# 4  
Old 10-31-2011
MySQL
Wow! Thanks....those were amazingly fast replies!

What is the difference between the two methods? Is there a difference (in any scenario) or is it just a matter of personal choice?
# 5  
Old 10-31-2011
The preferred way is this one:
Code:
count=$(grep -c "string" "filename")

There is an explanation, why this is preferred but I can't find it now... maybe someone else has the link!

Also, try searching the forum before posting questions. There are a lot of question like yours: Google Search Results for store command result | The UNIX and Linux Forums
# 6  
Old 10-31-2011
iirc, $(...) is the POSIX version, and backquoting functionality isn't required by the standard. Although I could be wrong...
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Programming

Python - store output of command to a variable

I am trying to store output of python command in variable. Could you please help how I can do that ? For example I am executing the following command - "CentOS" in server_desc The output would be True or False I would like to store the output in a variable say outPut and use condition... (4 Replies)
Discussion started by: atanubanerji
4 Replies

2. Shell Programming and Scripting

Store command inside variable

Is it possible to store a command inside a variable? i want this piece to be stored inside a variable, so i can use it later in a different command $u | cut -d " " -f 2 var="$u | cut -d " " -f 2" eval $var I tried to use eval but I receive this error: -f 2: command not found ... (5 Replies)
Discussion started by: velos
5 Replies

3. Shell Programming and Scripting

variable value return of multiple command

I wrote this script #!/bin/bash var=`du -sch /var/log/messages;du -sch /var/log/maillog` echo $var I am getting result as follows. # sh my.sh 2.1M /var/log/messages 2.1M total 296K /var/log/maillog 296K total I need it like below 2.1M /var/log/messages 296K... (3 Replies)
Discussion started by: anilcliff
3 Replies

4. Shell Programming and Scripting

To store the file name o/p from find command in to a variable

Hi How to use a variable to store the filename of a file which was found by the 'find' command. can this be practical-->var = find . -name "filename.dat" Please help.. (1 Reply)
Discussion started by: ayyappaas
1 Replies

5. Shell Programming and Scripting

Using variable to store of find command

Hello Experts I am newbie to unix and writing one script to make archive files Problme i am facing is : I have used find command to find the type of files and I am storing find command results in a variable. When I echo the variable I can see that path is printed properly but when i am... (5 Replies)
Discussion started by: mitsyjohn
5 Replies

6. Shell Programming and Scripting

Not able to store command inside a shell variable, and run the variable

Hi, I am trying to do the following thing var='date' $var Above command substitutes date for and in turn runs the date command and i am getting the todays date value. I am trying to do the same thing as following, but facing some problems, unique_host_pro="sed -e ' /#/d'... (3 Replies)
Discussion started by: gvinayagam
3 Replies

7. Shell Programming and Scripting

Store highest filename from ls command to a variable

I am sure it has been answered in some form or the other in this forum but trust me I have spent last couple of hours looking for an answer but can't find it. I want to do a very simple operation within my script. Let's say I have 4 files with the names file1.log, file2.log, file3.log and... (6 Replies)
Discussion started by: sssccc
6 Replies

8. 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

9. Shell Programming and Scripting

how to store grep command in a Variable

I have a variable A echo $A 5060 I am exporting the value X,Y,Z and it id fetching right thing and When I run C=`${X} -l ${Y} ${Z} "trap '' INT;. ~/.profile >/dev/null 2>/dev/null; netstat -na | grep \$A`" here it is going to same directory and also running netstat -na | grep 5060 ... (4 Replies)
Discussion started by: madhusmita
4 Replies

10. UNIX for Dummies Questions & Answers

How to Store command O/P to a variable...

Hi all.. I got a problem.. Its easy to redirect o/p to a file.. But Is it possible to redirect the O/P to a variable? For example: I've a command in my script: string1=cut -d ':' -f2 file.txt When I do: echo $string1 The value is empty... Pls suggest me how to store the value... (7 Replies)
Discussion started by: smartbuddy
7 Replies
Login or Register to Ask a Question