Parse the output of command in a shell script and store the result in a variable

Question

When I execute the following svn command, I get the below output.

$ svn log -r 1:HEAD --limit 1 http://plugins.svn.wordpress.org/bulk-delete
------------------------------------------------------------------------
r91525 | plugin-master | 2009-02-03 10:39:23 +0530 (Tue, 03 Feb 2009) | 1 line

adding bulk-delete by sudar
------------------------------------------------------------------------

I am writing a shell script and I want to parse the output of the above command and get the revision number (r91525 in this case) and store it in a shell variable, so that I can use it in the subsequent commands.

I tried the cut command and was able to get the revision number in the second line, but the other lines were still appearing.

$ svn log -r 1:HEAD --limit 1 http://plugins.svn.wordpress.org/bulk-delete | cut -f1 -d'|'
------------------------------------------------------------------------
r91525 

adding bulk-delete by sudar
------------------------------------------------------------------------

Question: How to retrieve the revision number and store in a shell variable, so that I can use it in the subsequent commands?

if what you need is the latest revision, see http://stackoverflow.com/a/111173/393701 — SirDarius, Dec 19 '12 at 15:11
@SirDarius No, I don't want the latest version. I want the version in which this directory was introduced. — Sudar, Dec 19 '12 at 15:40

score 2 · Answer 1 · answered Dec 19 '12 at 15:13

2

try this :

svn blahblah |awk 'NR==2{print $1;exit;}'

test:

kent$  echo "------------------------------------------------------------------------
r91525 | plugin-master | 2009-02-03 10:39:23 +0530 (Tue, 03 Feb 2009) | 1 line

adding bulk-delete by sudar
------------------------------------------------------------------------"|awk 'NR==2{print $1;exit;}'
r91525

answered Dec 19 '12 at 15:13

Kent

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This answers one part of my question. But how do I store the result in a shell variable? – Sudar Dec 19 '12 at 15:44
@Sudar try `var=$(svn ...|awk ...)` then echo $var you should see the value was stored. – Kent Dec 19 '12 at 15:47
This works, but I am accepting the other answer since he also gave the tcsh version. Upvoted though .. – Sudar Dec 19 '12 at 16:01

dwalter · Accepted Answer · 2012-12-19T15:46:53.423

2

You can use sed for this.

  svn log --limit 1 | sed -n -e 's/^\(r[0-9]\+\).*/\1/p'

this will print out only the revision e.g. r1234

If you need only the number of the revision use

  svn log --limit 1 | sed -n -e 's/^r\([0-9]\+\).*/\1/p'

UPDATE: to store it in a variable use

bash:

REVISION=$(svn log --limit 1 | sed -n -e 's/^r\([0-9]\+\).*/\1/p')

tcsh

  set revision = `svn log --limit 1 | sed -n -e 's/^r\([0-9]\+\).*/\1/p'`

edited Dec 19 '12 at 15:46

answered Dec 19 '12 at 15:13

dwalter

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This answers one part of my question. But how do I store the result in a shell variable? – Sudar Dec 19 '12 at 15:45

Parse the output of command in a shell script and store the result in a variable

2 Answers2