Using the terminal (in OSX), how do I modify a specific line of a file?
e.g. I have a javascript file and want to comment out line 300 by prepending //
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chepner
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Ashley Coolman
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Don't put solutions in your question; if you use something substantially different from the accepted answer, add an answer of your own. – chepner Nov 26 '15 at 13:15
1 Answers
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The easiest way is to use sed:
sed -i '300s%^%//%' myfilename.js
Some versions of sed (such as the BSD version that ships with Mac OS X), require an explicit argument for -i. If you don't want a backup, use the empty string.
sed -i "" '300s%^%//%' myfilename.js
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Thanks but it didn't actually work for me: `command a expects \ followed by text` – Ashley Coolman Nov 26 '15 at 11:59
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1@AshleyCoolman: It definitely does work. Are you sure you typed it exactly? And did you get an error message? – psmears Nov 26 '15 at 12:00
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Hm `sed -i '1679s%^%//%' angular-protractor.d.ts` gets me `sed: 1: "angular-protractor.d.ts": command a expects \ followed by text` – Ashley Coolman Nov 26 '15 at 12:03
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Ah I should of mentioned I'm on OSX: http://stackoverflow.com/questions/2320564/variations-of-sed-between-osx-and-gnu-linux – Ashley Coolman Nov 26 '15 at 12:08
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Ok thanks mate - san you add the a version for OSX with `-e` to your answer? – Ashley Coolman Nov 26 '15 at 12:34
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1The proper solution is to provide `-i` with an explicit argument; it's not clear why adding `-e` works, but a comment in the linked question indicates that it does not always work. – chepner Nov 26 '15 at 13:21