Bash: Grabbing output of command line program execution and setting to variable

Question

I am running a command in CentOS that gives me an output of a multiple line string and I want to grab a certain part of that output and set it to a variable.

For example I run the commandline

ebi-describe-env

My output as follows:

ApplicationName | CNAME | DATECreated | DateUpdated | Description | EndpointURL |   
EnvironmentID | EnvironmentName | Health | Stack | Status | TemplateName | 
Version Label -------------------------------------
Web App | domain.com | 2012-02-23 | 2012-08-31 | |
anotherdomain.com | e-8sgkf3eqbj | Web-App-Name | Status | 
Linux | Ready | N/A | 20120831 - daily

I want to grab the '20120831-daily' part of the multi-string which is in the same place every call and set it to a variable. I believe the '------' means a new line or output.

I'm very new to bash scripting, so any help would be great. Thank you.

Note: I asked the question before and it was solved with awk, but it turned out it was only for a one line output. Previous question

Ben Jackson · Accepted Answer · 2012-09-05 20:52:14Z

2

You can easily add a pattern to match a particular line to the previous answer:

awk -F"|" 'NR == 6 {print $NF}'

The "pattern" for a block in awk can be any conditional. In my example NR is the line number, so that prints the last (pipe-separated) word on line 6. You could also use a pattern like /Linux/ if you want the line that has "Linux" in it.

answered Sep 5, 2012 at 20:52

Ben Jackson

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chepner · Accepted Answer · 2012-09-05 20:53:31Z

1

This should do the trick:

dateStr=$( ebi-describe-env | grep "Linux | Ready" | cut -t"|" -f4 )

Run the command and pipe its output through grep, which will only pass lines (well, the line) that contain the string "Linux | Ready". This is then passed to cut, which treats "|" as a delimiter and only prints the 4th field. The output is then captured by the $(...) construct and assigned to the variable dateStr.

Slightly better is Ben Jackson's awk solution, which can replace my grep/cut combination:

dateStr=$( ebi-describe-env | awk -F"|" 'NR==6 {print $NF}' )

answered Sep 5, 2012 at 20:53

chepner

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