SED Help

Posted on 2012-03-23
Medium Priority
Last Modified: 2013-11-13
Hi all,

I am currently writing a command that allows me to appending a '#' in line of a text to help me disable a script (main.sh) from calling a sub-script (test.sh)

I have managed to get it working like this:

sed -i 's:./test.sh:#./test.sh:g' main.sh

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however i need to have another script to have the '#' removed to re-enable the call.

and it works like this:

sed -i 's:#./test.sh:./test.sh:g' main.sh

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it works ok assuming that the first command is only run once, however should it be run multiple times (in this case 4 times), this is the output:


as a result the second script needs to be run 4 times in to remove all instances of '#'.

How should i approach this?

 Should i fix the first script to ensure only one # is allowed to be appended prior to test.sh? or
should i fix the second script to ensure all instances of '#' are removed before test.sh?

appreciate any help as i am still relatively new to SED.

Question by:jaglin84
LVL 85

Accepted Solution

ozo earned 536 total points
ID: 37756210
sed -i 's:#*./test.sh:./test.sh:g' main.sh
LVL 85

Assisted Solution

ozo earned 536 total points
ID: 37756217
sed -i 's:#*./test.sh:#./test.sh:g' main.sh

Expert Comment

ID: 37783570
Sed uses regular expressions in its syntax, so you only need to add a * after a char to consider it multiple times
LVL 20

Assisted Solution

simon3270 earned 264 total points
ID: 37828318
Alternatively, fix the problem in the "comment out" script - use this (assuming that the "." of "./test.sh" is in the first column of the file):
sed -i 's:^./test.sh:#./test.sh:g' main.sh

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LVL 53

Expert Comment

ID: 38249566
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.

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