Remove comments from files

sed -e '/^#/d' -e 's/#.*$//' in
Use sed to remove comments from a file. In this example the comments begin with #. The command '/^#/d' remove line starting with #. The command 's/#.*$//' remove comments at end of lines.

By: agambier
2012-01-25 15:05:57

1 Alternatives + Submit Alt

What Others Think

Just take care when the '#' is used for any other purpose than commenting ! - in a string - in bash substitution like ${variable#}
frans · 440 weeks and 1 day ago
A decent effort but its flawed as Franz pointed out above.. as well as his examples it also removes shebang lines. Removing comments at end of lines is a tricky problem no doubt.
zlemini · 439 weeks and 4 days ago
Sorry, But I did not understand the syntax of this command, but the line below is also an alternative to remove the comments "#" of the specified files. sed-i-r 's /^#// g' testes.txt The command you provided is just a filter on the file and print only after the same lines that do not have comments, or if the case of a configuration file, you can print only the rows that do not have the "#". I hope to have collaborated with everyone! Att, Julio C. S. Ferraz
julioferraz · 439 weeks and 4 days ago
frans: you're right, but I used this command to remove comments from a configuration file not a script file. To protect shebang you can use the following command: sed -e 's/^#!/__SHEBANG__/' -e '/^#/d' -e 's/#.*$//' -e 's/^__SHEBANG__/#!/' The shebang is first shebang '#!' replaced by __SHEBANG__ so the line won't be removed then comments are removed and at last __SHEBANG__ is replaced by the real shebang '#!'. I guess there's a another cleaner way to perform it. But it doesn't fix the case showed by frans.
agambier · 439 weeks and 3 days ago
When I saw this, I feel this is a fantastic command key. But when i try this on my work, I don't know why it's not working. And also you need to visit to complete your quality task easily. And showing some error here. Kindly get me out of this trouble. Thanks in advance.
SamLogue · 11 weeks and 4 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: