BASH Tips and Tricks
All tips courtesy @devinburnette
Basics
$ w
see who else is on box
$ w
14:15 up 5 days, 19:23, 7 users, load averages: 1.47 1.56 1.82
USER TTY FROM LOGIN@ IDLE WHAT
ktravers console - Mon11 3days -
_mbsetupuser console - Mon11 3days -
ktravers s000 - Mon11 1:35 gulp
ktravers s001 - Mon11 - w
ktravers s002 - Mon11 4:10 node /Users/ktravers/.nvm/versions/node/v6.2.2/bin/sails lift
ktravers s004 - Mon11 3days /usr/local/Cellar/rabbitmq/3.5.1/erts-6.1/bin/../../erts-6.1/bin/beam.smp -W w -K true -A30
ktravers s005 - Mon11 3days redis-server *:6379
$ write [user]
send message to specific user
$ wall
broadcast to all users on box
$ whoami
get your current user
$ whoami
ktravers
$ who am i
verbose get current user
$ who am i
ktravers ttys001 Aug 29 11:06
$ clear
put command line at top of window
$ man [whatevs]
get manual for [whatevs] command
$ man man
man(1) man(1)
NAME
man - format and display the on-line manual pages
SYNOPSIS
man [-acdfFhkKtwW] [--path] [-m system] [-p string] [-C config_file] [-M pathlist] [-P pager] [-B browser] [-H html-
pager] [-S section_list] [section] name ...
...
$ history
readout of bash history
$ history
397 git log
398 cap production deploy
399 glr
400 glr
401 gbv
402 git branch -d next-lesson-bugfix
403 git branch -d slack-bugfix
404 gco -b slack-bugfix
405 gst
$ !515
run bash history command number
$ !!
re-run last bash history command
$ mkdir foo
$ cd !$
make directory and change into it
$ cd -
change into last directory you were in
Keyboard shortcuts
CTRL + k => delete from cursor to end of line
CTRL + u => delete from cursor to beginning of line
CTRL + y => print deleted chars back
CTRL + s => to go forward in history
CTRL + r => to go back in history
Searching
$ grep rails foo
search
$ grep -A2 -B2 rails foo
search and show before and after
$ grep -v rails foo
everything except rails
$ grep -i Rails foo
case insensitive search
$ grep -o rails
match search
$ grep -e [expression] / # $ egrep [expression]
pass expression to search
$ sed 's/Passenger/Logan/g' foo
search and replace (where / is a delimiter)
$ sed -i 's/Passenger/Logan/g' foo
search and replace case insensitive (where / is a delimiter)
$ sed '/Logan/d' foo
search and delete Logan (where / is a delimiter)
Note on delimiter:
/ is a tricky choice if searching for paths, bc need to escape each /
Use + instead, for example
$ cat foo | awk -F: {print $1}
get everything before first column
$ awk /UID/,/Logan\ Rackapp/ foo
get everything between two points
$ locate ruby
find every file with “ruby” in its path
Note: has to be turned on =>
$ launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist
$ find / -iname ruby
real time recursive lookthrough all system files
$ find / -iname ruby -type f -mtime +30
real time recursive lookthrough all system files
-type f => only files
-mtime +30 => return only files modified time older than past 30 days
$ find / -iname ruby -type f -mtime +30 -exec ls -l {}
run execution on all found files
System
$ ps
current user processes running
$ ps
PID TTY TIME CMD
1772 ttys000 0:00.35 -bash
55712 ttys000 0:35.49 /Users/ktravers/.rvm/rubies/ruby-2.2.2/bin/ruby bin/rails s
55720 ttys000 0:00.60 npm
55721 ttys000 27:02.15 gulp
4199 ttys001 0:02.26 -bash
5028 ttys002 0:00.29 -bash
29345 ttys002 0:04.80 node /Users/ktravers/.nvm/versions/node/v6.2.2/bin/sails lift
6678 ttys004 0:00.20 -bash
8845 ttys004 9:44.14 /usr/local/Cellar/rabbitmq/3.5.1/erts-6.1/bin/../../erts-6.1/bin/beam.smp -W w -K true -A30 -P 1048576 -- -root /us
7487 ttys005 0:00.19 -bash
8844 ttys005 0:49.27 redis-server *:6379
$ ps aux
all processes running
$ ps aux
USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
ktravers 55721 28.8 0.3 3251428 21468 s000 S+ 12:34PM 27:09.25 gulp
_windowserver 248 6.7 0.7 3624064 58676 ?? Ss Fri06PM 197:29.40 /System/Library/Frameworks/ApplicationServices.framework/Frame
_coreaudiod 137 4.8 0.1 2500488 4592 ?? Ss Fri06PM 13:58.15 /usr/sbin/coreaudiod
ktravers 1672 2.7 3.5 3699432 296196 ?? S Mon11AM 64:49.15 /Applications/Google Chrome.app/Contents/MacOS/Google Chrome -
ktravers 1673 2.4 1.5 2793764 125056 ?? S Mon11AM 17:46.66 /Applications/Utilities/Terminal.app/Contents/MacOS/Terminal -
ktravers 54234 1.2 1.5 3485456 128292 ?? S Wed11AM 6:13.23 /Applications/Google Chrome.app/Contents/Versions/52.0.2743.11
ktravers 18832 0.9 2.0 3685316 168976 ?? S 5:21PM 3:11.80 /Applications/Google Chrome.app/Contents/Versions/52.0.2743.11
ktravers 66895 0.4 3.6 3931612 301060 ?? S Wed12PM 5:36.17 /Applications/Google Chrome.app/Contents/Versions/52.0.2743.11
ktravers 1742 0.3 3.5 4015008 292568 ?? S Mon11AM 19:10.98 /Applications/Google Chrome.app/Contents/Versions/52.0.2743.11
ktravers 9924 0.2 3.3 3101936 273696 ?? S 4:20PM 8:15.92 /Applications/Sublime Text.app/Contents/MacOS/Sublime Text
ktravers 67279 0.1 0.0 2471188 3964 ?? S Tue11AM 2:12.74 /Applications/Utilities/Adobe Creative Cloud/CoreSync/Core Syn
ktravers 55712 0.1 1.9 2701340 158856 s000 S+ 12:34PM 0:35.54 /Users/ktravers/.rvm/rubies/ruby-2.2.2/bin/ruby bin/rails s
root 104 0.1 0.0 2473708 2560 ?? Ss Fri06PM 11:13.25 /usr/libexec/hidd
...
$ netstat -an
shows all connected and listening ports and sockets
$ netstat -an
Active Internet connections (including servers)
Proto Recv-Q Send-Q Local Address Foreign Address (state)
tcp4 0 0 192.168.2.58.54966 54.152.118.174.443 ESTABLISHED
tcp4 0 0 192.168.2.58.54959 52.205.164.104.443 ESTABLISHED
tcp4 0 0 192.168.2.58.54953 104.237.191.1.443 ESTABLISHED
...
$ wc foo
word count, line count, character count
$ wc -w
word count only
$ netstat -an | grep :22 | wc -l
port connection count
$ lsof
list open files on system (and what process is keeping them open)
$ lsof
total 80
drwxr-xr-x 19 ktravers 646 Aug 1 13:06 .
drwxr-xr-x 10 ktravers 340 Aug 8 19:09 ..
drwxr-xr-x 15 ktravers 510 Sep 1 14:55 .git
-rw-r--r-- 1 ktravers 90 Aug 20 2015 .gitignore
-rw-r--r-- 1 ktravers 336 Aug 20 2015 404.md
-rw-r--r-- 1 ktravers 1867 Aug 1 13:06 _config.yml
drwxr-xr-x 5 ktravers 170 Aug 20 2015 _includes
drwxr-xr-x 5 ktravers 170 Aug 20 2015 _layouts
drwxr-xr-x 25 ktravers 850 Sep 1 14:12 _posts
drwxr-xr-x 6 ktravers 204 Aug 20 2015 _scss
-rw-r--r-- 1 ktravers 572 Sep 10 2015 about.md
drwxr-xr-x 34 ktravers 1156 Mar 8 17:13 assets
-rw-r--r-- 1 ktravers 21 Aug 20 2015 CNAME
-rw-r--r-- 1 ktravers 789 Aug 20 2015 feed.xml
drwxr-xr-x 8 ktravers 272 Aug 20 2015 images
-rw-r--r-- 1 ktravers 403 Aug 20 2015 index.html
-rw-r--r-- 1 ktravers 1077 Aug 20 2015 LICENSE
-rw-r--r-- 1 ktravers 521 Aug 20 2015 README.md
-rwxr-xr-x 1 ktravers 3868 Aug 20 2015 style.scss
Network
$ ifconfig
network config on box