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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.




count how many times a string appears in a (source code) tree

Terminal - count how many times a string appears in a (source code) tree
grep -rc logged_in app/ | cut -d : -f 2 | awk '{sum+=$1} END {print sum}'
2009-07-15 14:16:44
User: terceiro
Functions: awk cut grep
count how many times a string appears in a (source code) tree

grep's -c outputs how may matches there are for a given file as "file:N", cut takes the N's and awk does the sum.


There are 3 alternatives - vote for the best!

Terminal - Alternatives
$ grep -or string path/ | wc -l
2009-07-16 12:50:59
User: ioggstream
Functions: grep wc

grep -o puts each occurrence in a separate line

Know a better way?

If you can do better, submit your command here.

What others think

if you leave out the -c option of grep then you can get wc to do the counting for you:

grep -r PATTERN app/ | wc -l

because then grep returns one match per line.

Comment by bwoodacre 293 weeks and 5 days ago

Strictly speaking this is how many *lines* upon which the string appears:

echo foo foo |grep -c foo


You can use sed to add newlines after your input string to put each on a line by itself, to count them accurately:

grep -r foo app/ | sed -e 's/foo/&\n/g' |grep -c foo
Comment by eichin 293 weeks and 5 days ago


$ awk -F\: '{sum+=$2} END {print sum}'

Comment by ioggstream 293 weeks and 4 days ago

Good catch eichin. Although I think using wc is still a decent approximation. Another way if you're only searching for a single word is to turn all spaces into newlines:

grep -r PATTERN app/ | tr ' ' '\n' | wc -l

although as soon as you want to search for "Micheal Jackson" this approach fails and you have use eichin's approach.

Comment by bwoodacre 293 weeks and 4 days ago

I missed the -o option on my first pass through the grep manpage. Indeed -o gets what we really want:

grep -ro PATTERN . | wc -l
Comment by bwoodacre 293 weeks and 4 days ago

ooh, I hadn't seen that before, nice. (As noted in the other thread, -o and -c don't play well together, but it's still a much nicer way to get non-overlapping matches, and it lets you avoid repeating the string too...)

Comment by eichin 293 weeks and 3 days ago

Your point of view

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