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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.




Commands using cat from sorted by
Terminal - Commands using cat - 417 results
cat subtitles.txt | perl -pe 's/} /}/g; s/{(\d+)}/=1=/; $f1=(24/25*$1); s/{(\d+)}/=2=/; $f2=(24/25*$1); $f1=~s/\..*//; $f2=~s/\..*//; s/=1=/{$f1}/; s/=2=/{$f2}/; ' > subtitles_newfps.txt
2011-07-30 15:34:43
User: ciekawy
Functions: cat perl

this command example converts to 25 fps subtitles that were originally created for 24 fps movie

find src/ -name "*.java" | while read f; do echo -n "$f "; cat "$f" | tr -dc '{}'; echo; done | awk '{ print length($2), $1 }' | sort -n
pdftk input1.pdf input2.pdf cat output output.pdf
MAC=$((date +'%Y%m%d%H%M%S%N'; cat /proc/interrupts) | md5sum | sed -r 's/(..)/\1:/g' | cut -d: -f 1-6)
2011-07-14 13:11:50
User: jazznjam
Functions: cat cut date md5sum sed

I liked vaporub's suggestion, here a little simplification of the sed command.

cat video.avi.001 video.avi.002 video.avi.003 >> video.avi
cat my.sandbox.cnf | awk -F "=" 'NF < 2 {print} sub("=", "=~placeholder~=") {print}' | awk -F "=~placeholder~=" 'NF < 2 {gsub("-", "_", $0); print} NF==2 {gsub("-", "_", $1); print $1 "=" $2}'
2011-07-06 09:35:55
User: ShlomiNoach
Functions: awk cat

Multi-word parameters in my.cnf can be written with either hyphens or underscores. innodb_file_per_table is the same as innodb-file-per-table, as well as innodb_file-per_table. The script normalizes the parameter names to using underscores only, keeping from changing values (e.g. ?mysql-bin? parameter value should not change).

cat my.cnf | sed '/^#/d' | sed '/^$/d' | sed -e 's/[ \t]\+//g'
cat /etc/issue
2011-06-22 15:04:45
User: h3nr1x
Functions: cat

Another way of do it in debian like distros, don't know if works for others

if [ -x /etc/*-release ]; then cat /etc/*-release ; else cat /etc/*-version ; fi
cat /etc/*-release
cat > file.txt << EOF
2011-06-18 17:00:38
User: ThePCKid
Functions: cat

This command should be the first file-editing command for a newbie. It clears file.txt (cat), and asks for input until EOF is entered on its own line (not written to file.txt).

cat /sys/class/net/*/address
2011-06-03 05:52:37
User: houghi
Functions: cat
Tags: mac

No need for the ls -r and a sort is also not really needed.

cat /etc/passwd | wc -l
cat `ls -r /sys/class/net/*/address` | sort -u
cd /usr/share/gnome-shell/search_providers/ && cat google.xml | sed "s/www.google.com\/search/duckduckgo.com\//; s/Google/DuckDuckGo/g" > duckduckgo.xml
2011-05-27 22:07:36
User: scripteles
Functions: cat cd sed

Add DuckDuckGo Search as search provider on gnome-shell/gnome3 .

Needs root permission. To see the results, use alt+f2 and then type r.

cat /dev/hda|netcat -q 0 9100
2011-05-22 05:03:28
User: robosquid
Functions: cat

Where is a printer with jet-direct.

No, I don't suggest this as a backup method.

cat /proc/mounts | awk '{print $2}' | grep "^$MOUNTPOINT" | sort -r | xargs umount
2011-05-17 05:54:42
User: boni
Functions: awk cat grep sort xargs

Original: https://bugzilla.redhat.com/show_bug.cgi?id=194342

mysqldump OLD_DB | cat <(echo "CREATE DATABASE NEW_DB; USE NEW_DB;") - | mysql
2011-05-16 20:42:01
User: michaelmior
Functions: cat echo

This should probably only be used for testing in a dev environment as it's not terribly efficient, but if you're doing something that might trash a DB and you still want the old data available, this works like a charm.

cat /sys/class/net/eth0/address
cat search_items.txt | while read i; do surfraw google -browser=firefox $i; done
2011-05-12 09:27:08
User: bubo
Functions: cat read

tired of opening tabs and fill in search forms by hand? just pipe the search terms you need into this surfraw loop. you can use any browser you have installed, but a graphical browser with a tabbed interface will come in handy. surfraw can be found here:


nohup cat /dev/ttyS0 | tee -a llamadas.db&
find . -type f -name '*.php' | xargs cat | sed -re ':top /\/\*.*\*\// { s/\/\*.*\*\///g ; t top }; /\/\*/ { N ; b top }' | awk '$0 !~ /^[\t[:space:]]*($|(\/\/)|(#))/' | wc -l
2011-05-05 06:12:34
User: andrehgw
Functions: awk cat find sed top wc xargs

An advanced possibility to count the lines of code like in #8394

grabtweets() { curl -s -o $GT_TMP twitter.com/$1 | cat $GT_TMP | grep entry-content | sed -e :loop -e 's/<[^>]*>//g;/</N;//bloop' | sed 's/^[ \t]*//'; }
pdftk inp1.pdf inp2.pdf inp3.pdf cat output out.pdf
cat username_lovedtracks.xspf |perl -pe "s/.*<title>(.*)<\/title><creator>(.*)<\/creator>.*/Song: \1 Artist: \2/gi"> titles
2011-04-07 09:02:11
User: dustylc
Functions: cat perl

Change your exported xml love list from last.fm, into Song: songname Artist: artistname