Bryce Carlson

Basic Brilliant Scripting for Beginners

Bryce Carlson Basic Bash for Beginners Basic Brilliant Scripting for Beginners Bryce Carlson bash script for macOS Bryce Carlson •Senior Support Engineer at Jamf •Previously at (pre 1/2016): •UW - Green Bay •Appleton Area School District

Agenda •Why use a script? •Basic anatomy of a script •Logic •Results (for Inventory) •End User interaction in scripts •Good commands to have •Questions

Why use a script? Command - Set Time Zone

sudo systemsetup -settimezone America/Chicago Command - Set Time Zone and…

sudo systemsetup -settimezone America/Chicago sudo systemsetup -setnetworktimeserver time.apple.com

sudo ntpdate -u time.apple.com Command - Set Time Zone and…

Last login: Mon Jun 18 15:27:23 on ttys000 carlson-jamf-mbp:~ bryce$ sudo systemsetup -settimezone America/ Chicago Set TimeZone: America/Chicago carlson-jamf-mbp:~ bryce$ sudo systemsetup -setnetworktimeserver time.apple.com setNetworkTimeServer: time.apple.com carlson-jamf-mbp:~ bryce$ sudo ntpdate -u time.apple.com 19 Jun 15:28:36 ntpdate[6607]: adjust time server 17.253.14.253 offset 0.003109 sec carlson-jamf-mbp:~ bryce$ ⁉ ~/Desktop/some-script.txt Text/Script Editors

https://www.sublimetext.com sudo nano http://www.barebones.com/products/textwrangler/ http://www.barebones.com/products/bbedit/

https://atom.io Text/Script Editors #!/bin/sh # #This script will set system timezone, NTP Server, and sync the clock, and remove skew # #set to US Central Time systemsetup -settimezone America/Chicago #set ntp server to time.apple.com systemsetup -setnetworktimeserver time.apple.com #runs an ntp update ntpdate -u time.apple.com Basic anatomy of a script The Script #!/bin/sh # #This script will set system timezone, NTP Server, and sync the clock, and remove skew # #set to US Central Time systemsetup -settimezone America/Chicago #set ntp server to time.apple.com systemsetup -setnetworktimeserver time.apple.com #runs an ntp update ntpdate -u time.apple.com The Script #!/bin/sh Interpreter line = Comment # # #This script will set system timezone, NTP Server, and sync the clock, and remove skew #

#set to US Central Time Command to run systemsetup -settimezone America/Chicago #set ntp server to time.apple.com systemsetup -setnetworktimeserver time.apple.com #runs an ntp update ntpdate -u time.apple.com The Script

~/Desktop/scripts/set-ntp.sh

sudo sh ~/Desktop/scripts/set-ntp.sh

#!/bin/sh # #This script will set system timezone, NTP Server, and sync the clock, and remove skew # #set to US Central Time systemsetup -settimezone America/Chicago #set ntp server to time.apple.com systemsetup -setnetworktimeserver time.apple.com #runs an ntp update ntpdate -u time.apple.com Logic Logic

•IF, THEN, DO, ELSE, DO, FI

•WHILE, DO, DONE Logic

• IF, THEN, DO, ELSE, DO, FI • “If we have this ﬁle, then do this command. If not move on.” • WHILE, DO, DONE • “While this ﬁle is here do this. When it is gone, or if it was never there move on.” IF THEN Example

DO THEN

IF FI .app

ELSE DO #!/bin/sh # if [ -f "/Applications/Minecraft.app" ]; then rm /Applications/Minecraft.app else say “Thanks for not playing games” fi #!/bin/sh # if [ -f "/Applications/Minecraft.app" ]; then Operatorrm /Applications/Minecraft.app else say “Thanks for not playing games” fi #!/bin/sh # if [ -f "/Applications/Minecraft.app" ]; then rm /Applications/Minecraft.app else osascript -e 'display notification "Thanks for not playing games." with title “Thanks!"' # fi Logic - Operators

Operator What it does -f Looks for ﬁle -d Looks for folder

File X -nt File Y If file X is newer than file Y (according to modification date) File X -ot File Y If file X is older than file Y x = y Value equals value x != y Value does not equal value x -gt y X is greater than Y x -lt y X is less than Y Logic - Operators

carlson-jamf-mbp:~ bryce$ help test WHILE DO Example

DO WHILE DONE

.app #!/bin/sh # while [ -f “/Applications/Minecraft.app” ]; do echo “The game is here; removing” rm /Applications/Minecraft.app done echo “All good here we will move on now" WHILE DO Example

WHILE sleep 60 DONE

.appdownload #!/bin/sh # while [ -f /Applications/*.appdownload ]; do echo "Apps Installing" sleep 60 done echo "Apps Done Installing" Results (for Inventory) Scenarios

• You want to know the date and time of the last password change for your technician account on client Macs. • Security auditing needs to know if the Security Update 2018-001 is installed on client Macs. User’s last password change dscl . read /Users/ladmin | grep --context=3 passwordLastSetTime carlson-jamf-mbp:~ bryce$ dscl . read /Users/ladmin | grep --context=3 passwordLastSetTime 0 failedLoginTimestamp 0 passwordLastSetTime 1522616296.202925 User’s last password change

#!/bin/sh # #grabs and stores user PW info and strips EPOCH to one number etime=`dscl . read /Users/ladmin | grep --context=3 passwordLastSetTime` etime2=`echo $etime | sed -n 's:.*$.*$.*:\1:p'` etime3=`echo ${etime2%.*}` # #real time rtime=`date -r $etime3 '+%m/%d/%Y:%H:%M:%S'` echo "$rtime" # exit 0 User’s last password change

#!/bin/sh # #grabs and stores user PW info and strips EPOCH to one number etime=`dscl . read /Users/ladmin | grep --context=3 passwordLastSetTime`List users etime2=`echoVariable = $etime grave| accentsed -n 's:.*$.*$.*:\1:p'` etime3=`echo ${etime2%.*}` cuts tags # #real time $var rtime=`date -r $etime3 '+%m/%d/%Y:%H:%M:%S'` echo "$rtime" # date exit 0 $var User’s last password change User’s last password change User’s last password change

/usr/sbin/system_profiler SPInstallHistoryDataType carlson-jamf-mbp:~ bryce$ /usr/sbin/system_profiler SPInstallHistoryDataType Installations:

SU_TITLE:

Version: Source: Apple Install Date: 4/1/18, 4:40 PM

QuickAdd:

Version: Source: 3rd Party Install Date: 4/1/18, 5:07 PM

AMP for Endpoints Connector v1.6.0.582: Security Update 2018-001?

#!/bin/sh # #grabs and stores user SU info if Security Update 2018-001 is there swupdatelist=`/usr/sbin/system_profiler SPInstallHistoryDataType | grep "Security Update 2018-001" | awk '{ print $3 }'` swq=${swupdatelist%?}; swa="2018-001" # if [[ "$swq" == "$swa" ]]; then echo “Yes SU-2018-001.” > /Library/Globodyne/swu2018001-stat.txt else echo “No SU-2018-001.” > /Library/Globodyne/swu2018001-stat.txt fi Output # exit 0 End User interaction in scripts #!/bin/sh # userPrompt=“$(osascript -e 'display dialog “Is this a question for the user?” buttons {"Yes", "No"} default button "No"')" # if [ "$userPrompt" = "button returned:Yes" ]; then echo “They said yes” else echo “They said no” fi #!/bin/sh # userPrompt=“$(osascript -e 'display dialog “Is this a question for the user?” buttons {"Yes", "No"} default button "No"')"

# Command in var if [ "$userPrompt" = "button returned:Yes" ]; then echo “They said yes”If else $var = then echo “They said no” fi Scenario

• Mac users in the graphics area of the organization are talking about running low on disk free space. How can we help them clean up? Disk free df / carlson-jamf-mbp:~ bryce$ df / | awk '/dev\/disk/ {print substr($5,1,length($5) - 1)}' 59 carlson-jamf-mbp:~ bryce$ df / | awk '/dev\/disk/ {print $5}' 59% carlson-jamf-mbp:~ bryce$ df / Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on /dev/disk1s1 976695384 566976872 406254408 59% 1364491 9223372036853411316 0% / #!/bin/sh # diskusednumonly=`df / | awk '/dev\/disk/ {print substr($5,1,length($5) - 1)}'` currentuser=`ls -l /dev/console | awk '/ / { print $3 }'` diskusageallowed="90" # if [ "$diskusednumonly" -gt "$diskusageallowed" ]; then echo "The drive is more that 90 percent full. Will ask user for clean up." if [ "$(osascript -e 'display dialog "Looks like your boot drive is getting full. Can we clean Caches?" buttons {"Yes", "No"} default button "No"')" = "button returned:Yes" ]; then echo "Cleaning end user home folder" rm -rf /Users/$currentuser/Library/Caches/* else echo "No need to clean; user says they will" fi else echo "No need to clean. Drive is free." fi #!/bin/sh # diskusednumonly=`df / | awk '/dev\/disk/ {print substr($5,1,length($5)Disk free - 1)}'` currentuser=`ls -l /dev/console | awk '/ / { print $3 }'` diskusageallowed="90" # Current user print if [ "$diskusednumonly" -gt "$diskusageallowed" ]; then echo "The drive is more that 90 percent full. Will ask user for clean up." Greater than if [ "$(osascript -e 'display dialog "Looks like your boot drive is getting full. Can we clean Caches?" buttons {"Yes", "No"} default button "No"')" = "button returned:Yes" ]; then echoNested if "Cleaning end user home folder" rm -rf /Users/$currentuser/Library/Caches/* else echo "No need to clean; user says they will" fi else echo "No need to clean. Drive is free." fi Recap •Why use a script? •Basic anatomy of a script •Logic •IF, THEN, DO, ELSE, DO, FI •WHILE, DO, DONE •Operators •Results (for Inventory) •Extension Attribute •To a ﬁle •End User interaction in scripts •osascript - Open Scripting Architecture Good commands to have

man ANY COMMAND HERE

mdfind "kMDItemAppStoreCategoryType == '*game*'" carlson-jamf-mbp:~ bryce$ mdfind "kMDItemAppStoreCategoryType == '*game*'"

/Applications/Chess.app

installer -pkg /path/to/some.pkg -target /

sudo chmod +x /path/to/some/script.sh Questions? Thank you! [email protected]

@bryce.carlson

Feedback: https://bit.ly/psumac2018-292 Topics that came up after session

• Apple’s Shell Scripting Primer • https://developer.apple.com/library/archive/documentation/ OpenSource/Conceptual/ShellScripting/shell_scripts/shell_scripts.html

• How do I launch a script as a user at their log in, or not have it auto launch • Launch agent • More info here: http://www.launchd.info • bash Cookbook by O'Reilly Media • http://shop.oreilly.com/product/0636920058304.do Topics that came up after session

Thanks to Joseph K. for these! • Manuals • https://www.gnu.org/software/bash/manual/html_node/index.html# - Bash Reference Manual • BASH Reference • http://ss64.com/bash/ - SS64 Bash Index A-Z • http://www.tldp.org/guides.html - The Linux Documentation Project: Guides • https://learncodethehardway.org/unix/bash_cheat_sheet.pdf - Bash cheat sheet PDF, from Learn Code the Hard Way

• https://www.shellcheck.net/ - ShellCheck – shell script analysis tool • http://explainshell.com/ - explainshell.com • https://ss64.com/bash/syntax-keyboard.html - bash keyboard shortcuts | Bash | SS64.com • http://www.cs.mcgill.ca/~guide/help/man.html - MAN PAGES - HOW TO READ MAN PAGES • http://ss64.com/bash/ - SS64 Bash Index A-Z Topics that came up after session

Thanks to Joseph K. for these!

http://tldp.org/LDP/Bash-Beginners-Guide/html/index.html - Bash Guide for Beginners http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html - BASH Programming - Introduction HOW-TO http://www.bash.academy/ - The Bash Academy http://tldp.org/LDP/abs/html/index.html - Advanced Bash-Scripting Guide http://linuxsurvival.com/linux-tutorial-introduction/ - Linux Tutorial Introduction | Linux Survival http://ryanstutorials.net/bash-scripting-tutorial/ - Bash Scripting Tutorial - Ryans Tutorials https://www.youtube.com/watch?v=QGvvJO5UIs4 - Learn Bash Scripts - Tutorial - YouTube https://learnxinyminutes.com/docs/bash/ - Learn X in Y Minutes: Scenic Programming Language Tours https://www.howtogeek.com/67469/the-beginners-guide-to-shell-scripting-the-basics/ - The Beginner’s Guide to Shell Scripting: The Basics http://www.ee.surrey.ac.uk/Teaching/Unix/index.html - UNIX / Linux Tutorial for Beginners https://www.davidbaumgold.com/tutorials/command-line/ - Getting to Know the Command Line | David Baumgold https://www.youtube.com/playlist?list=PLtK75qxsQaMLZSo7KL-PmiRarU7hrpnwK - The Linux Basics Course - YouTube https://www.lynda.com/Mac-OS-X-10-6-tutorials/Unix-for-Mac-OS-X-Users/78546-2.html - Unix for Mac OS X Users https://developer.apple.com/library/content/documentation/OpenSource/Conceptual/ShellScripting/Introduction/ Introduction.html - developer.apple.com - Shell Scripting Primer Topics that came up after session

Thanks to Joseph K. for these!

http://web.mit.edu/mprat/Public/web/Terminus/Web/main.html - Terminus https://www.lynda.com/Bash-tutorials/What-you-need-know-before-continuing/142989/156629-4.html? srchtrk=index%3a0%0alinktypeid%3a2%0aq%3abash%0apage%3a1%0as%3arelevance%0asa%3atrue%0aproducttypeid%3a2 - Up and Running with Bash Scripting http://linuxcommand.org/index.php - LinuxCommand.org: Learn the Linux command line. Write shell scripts. https://www.lynda.com/Linux-tutorials/Learn-Linux-Command-Line-Basics/435539-2.html - Learn the Linux Command Line: The Basics

https://classroom.udacity.com/courses/ud595/lessons/4597278561/concepts/46968695970923 - Udacity - Linux Command Line Basics http://learnpythonthehardway.org/book/appendixa.html - Learn Python The Hard Way - Command Line Crash Course https://www.codecademy.com/en/courses/learn-the-command-line/lessons/manipulation/exercises/cp-i - Learn the Command Line | Codecademy https://www.jamfsoftware.com/resources/master-command-line-interface-basics/ - Master Command Line Interface Basics | JAMF Software