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commandlinefu.com is the place to record those command-line gems that you return to again and again.

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May 19, 2015 - A Look At The New Commandlinefu
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All commands from sorted by
Terminal - All commands - 12,371 results
find . -type f -name '*.c' -exec wc -l {} \; | awk '{sum+=$1} END {print sum}'
2009-09-04 15:51:30
User: arcege
Functions: awk find wc
Tags: awk find wc
-1

Have wc work on each file then add up the total with awk; get a 43% speed increase on RHEL over using "-exec cat|wc -l" and a 67% increase on my Ubuntu laptop (this is with 10MB of data in 767 files).

bc -l <<< "x=2; p=0.5; e(l(x)*p)"
watch -n <seconds> <command>
/sbin/badblocks -v /dev/fd0 1440
tcpdump -n -v tcp or udp or icmp and not port 22
du -a --max-depth=1 | sort -n | cut -d/ -f2 | sed '$d' | while read i; do if [ -f $i ]; then du -h "$i"; else echo "$(du -h --max-depth=0 "$i")/"; fi; done
2009-09-03 20:43:43
User: nickwe
Functions: cut du echo read sed sort
3

Based on the MrMerry one, just add some visuals to differentiate files and directories

ncdu
2009-09-03 20:38:32
User: nickwe
Tags: du ncdu ncurses
19

An NCurses version of the famous old 'du' unix command

find . -maxdepth 1 -type d|xargs du -a --max-depth=0|sort -rn|cut -d/ -f2|sed '1d'|while read i;do echo "$(du -h --max-depth=0 "$i")/";done;find . -maxdepth 1 -type f|xargs du -a|sort -rn|cut -d/ -f2|sed '$d'|while read i;do du -h "$i";done
2009-09-03 20:33:21
User: nickwe
Functions: cut du echo find read sed sort xargs
2

Based on the MrMerry one, just add some visuals and sort directory and files

watch -d 'ls -l'
2009-09-03 20:12:36
User: 0disse0
Functions: watch
Tags: watch stats
0

To highlight the difference between screen updates

watch 'cat /proc/loadavg'
2009-09-03 20:10:46
User: 0disse0
Functions: watch
Tags: status watch
1

If you need to keep an eye on a command whose output is changing, use the watch command. For example, to keep an eye on your load average

ioreg -l -p IODeviceTree | grep -o EFI[0-9]. && system_profiler SPSoftwareDataType |grep 64
gnome-terminal --tab --tab --tab
2009-09-03 19:36:07
User: 0disse0
Tags: terminal gnome
2

If you launch gnome-terminal manually, you can start with three open tabs

function checkfor () { while :; do $*; sleep 5; done; }
2009-09-03 19:35:42
User: relay
Functions: sleep
Tags: bash
1

checkfor: have the shell check anything you're waiting for.

'while : ; do' is an infinite loop

'$*' executes the command passed in

'sleep 5' - change for your tastes, sleep for 5 seconds

bash, ksh, likely sh, maybe zsh

Ctrl-c to break the loop

apt-key list
2009-09-03 19:32:11
User: 0disse0
Functions: apt
Tags: apt-key
0

For example: check the APT security keys to make sure the Google digital signature was imported correctly

apt-cache stats
man 5 crontab
2009-09-03 19:27:08
User: 0disse0
Functions: man
1

You can view the man pages from section five by passing the section number as an argument to the man command

function fcd () { [ -f $1 ] && { cd $(dirname $1); } || { cd $1 ; } pwd }
2009-09-03 18:58:13
User: relay
Functions: cd dirname pwd
Tags: bash ksh
1

fcd : file change directory

A bash function that takes a fully qualified file path and cd's into the directory where it lives. Useful on the commadline when you have a file name in a variable and you'd like to cd to the directory to RCS check it in or look at other files associated with it.

Will run on any ksh, bash, likely sh, maybe zsh.

find . -type f -exec grep -qi 'foo' {} \; -print0 | xargs -0 vim
2009-09-03 17:55:26
User: arcege
Functions: find grep xargs
Tags: vim find grep
-1

Make sure that find does not touch anything other than regular files, and handles non-standard characters in filenames while passing to xargs.

bash -x test.sh 2>&1 | tee out.test
2009-09-03 17:10:44
User: arcege
Functions: bash tee
3

Sends both stdout and stderr to the pipe which captures the data in the file 'out.test' and sends to stdout of tee (likely /dev/tty unless redirected). Works on Bourne, Korn and Bash shells.

echo $((3.0/5.0))
find . -exec grep foobar /dev/null {} \; | awk -F: '{print $1}' | xargs vi
grep -ir 'foo' * | awk -F '{print $1}' | xargs vim
grep -Hrli 'foo' * | xargs vim
2009-09-03 15:44:05
User: dere22
Functions: grep xargs
Tags: vim sed awk grep
3

The grep switches eliminate the need for awk and sed. Modifying vim with -p will show all files in separate tabs, -o in separate vim windows. Just wish it didn't hose my terminal once I exit vim!!

grep -ir 'foo' * | awk '{print $1}' | sed -e 's/://' | xargs vim
2009-09-03 15:12:27
User: elubow
Functions: awk grep sed xargs
Tags: vim sed awk grep
0

This will drop you into vim to edit all files that contain your grep string.

file /System/Library/Extensions/*.kext/Contents/MacOS/* |grep -i x86_64 |nl |tail -1 |cut -f1 -f3 && file /System/Library/Extensions/*.kext/Contents/MacOS/* |grep -v x86_64 |nl |tail -1 |cut -f1 -f3
2009-09-03 14:28:02
Functions: cut file grep nl tail
-1

Next time you see a mac fanboy bragging about 64-bitness of 10.6 give him this so he might sh?