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-   -   Sed append text to end of line if line contains specific text? How can this be done? (http://www.linuxquestions.org/questions/linux-newbie-8/sed-append-text-to-end-of-line-if-line-contains-specific-text-how-can-this-be-done-684650/)

helptonewbie 11-19-2008 11:10 AM

Sed append text to end of line if line contains specific text? How can this be done?
 
Hi All,
I'm trying to get sed to add some text to the end of a line if that line contains a specific piece of text.

Quite simple i have a script...
echo blah
df -h
echo blah1
cd /usr/share
echo blah2
ls -al
echo blah1

And i want to use sed (i think is probably right for the job) to add text to the end of all the lines that are 'echo'

I've seen that you can :-
sed 's/$/text/' filename

But that appends to every single line i want to do something like
sed 's|echo*$|>> /var/log/output_to_log.txt|' filename

As you can see i want all the echo's to send out to a log, in the script i've already created but at the moment the echo's just send to stout, and i could run the script with filename 2>&1 /var/log/output_to_log.txt, but i'm trying to do it this other way.

Any ideas?
Cheers,
MJ

makyo 11-19-2008 11:37 AM

Hi.

This works for me:
Code:

#!/bin/bash -

# @(#) s1      Demonstrate append text to end of selected lines.

echo
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version "=o" $(_eat $0 $1) sed
set -o nounset

echo
echo " Results:"
cat <<EOF |
echo blah
df -h
echo blah1
cd /usr/share
echo blah2
ls -al
echo blah1
EOF
sed '/^echo/s|$| >> /var/log/output_to_log.txt|'

exit 0

Producing:
Code:

% ./s1

(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash 2.05b.0
GNU sed version 4.1.2

 Results:
echo blah >> /var/log/output_to_log.txt
df -h
echo blah1 >> /var/log/output_to_log.txt
cd /usr/share
echo blah2 >> /var/log/output_to_log.txt
ls -al
echo blah1 >> /var/log/output_to_log.txt

The page http://www.grymoire.com/Unix/Sed.html is often mentioned as useful for learning sed ... cheers, makyo

Disillusionist 11-19-2008 11:43 AM

Deleted as makyo's example:

sed -i '/echo/s|$| >> /var/log/output_to_log.txt|' filename

is more relevant and elegant.

helptonewbie 11-19-2008 01:26 PM

Sweet thanks guys both ideas work great. And great website not seen that one before.. cheers
MJ

jheengut 10-23-2013 01:48 PM

so one liner
 
sed -e " /^http/s|$|\'| " -e "s/^http/\'http/"

sed -e " /^http/s|$|\'| ; s/^http/\'http/"

err to one liner ( better ) without two -e please


from

http://foo.foo.com

to

'http://foo.foo.com'


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