Scripting OS X. Armin Briegel. Mac Admin, Consultant and Author

Transcription

1 Scripting OS X Armin Briegel Mac Admin, Consultant and Author

2 Scripting OS X Armin Briegel Mac Admin, Consultant and Author

3 Scripting Bash Armin Briegel Mac Admin, Consultant and Author

4 Scripting Bash #! is not a curse word

5 Scripting Bash #! is just the beginning

6 #!*$%

7

8 scriptingosx.com/bash

9 bash

10 bash "bourne again shell",1989, GNU bsh "Bourne shell", 1979, UNIX v7 sh "Thompson shell", 1971

11 bash sh bsh bash bash3 bash4 v now

12 macos shells Built-in: sh bash (3.2) Optional fish bash (4.x) csh ksh tcsh zsh

13 bash

14 shell

15 Interactive Shell Interactive command line process control files and pipes UserShell: /bin/bash

16 Interactive Shell

17 Interactive Shell

18 shell

19 Shell Scripting interpret script files sequential commands control structures comments #!/bin/bash

20 shell UserShell: /bin/bash #!/bin/bash

21 shell UserShell: /bin/zsh #!/bin/bash

22 shell rshell: /usr/local/bin/fish #!/bin/bash

23 bash UserShell: /bin/bash #!/bin/bash

24 Scripting bash

25

26 Why?

27 Why? Automation Simplification Error prevention/avoidance Codifying Processes Documentation Share

28

29

30 where?

31 Everywhere!

32 Where? File and Metadata Management Installation scripts (pre-/postinstall) Configuration login scripts (settings/defaults/profiles) machine setup (networksetup/systemsetup) User Management creation/cleanup/deletion/promotion

33 Where? Data Gathering/Asset Management Jamf Extension Attributes Munki Report osquery Zentral

34 When? Events Triggers scheduled launchd login outset startup manually file events

35 an example

36 ssh "mkdir -p /tmp/pkgs" scp App.pkg ssh -t "sudo installer /tmp/pkgs/app.pkg -tgt /"

37 ssh "mkdir -p /tmp/pkgs" scp App.pkg ssh -t "sudo installer /tmp/pkgs/app.pkg -tgt /"

38 path="/tmp/pkgs" pkg="app.pkg" ssh "mkdir -p /tmp/pkgs" scp App.pkg ssh -t "sudo installer /tmp/pkgs/app.pkg -tgt /"

39 path="/tmp/pkgs" pkg="app.pkg" ssh $host "mkdir -p $path" scp $pkg $host:$path/$pkg ssh -t $host "sudo installer $path/$pkg -tgt /"

40 another example

41 Scripting bash pkgbuild --root payload --identifier pkg.policybanner --version installlocation /Library/Security PolicyBanner.pkg buildpolicybannerpkg.sh

42 Scripting bash pkgbuild --root payload --identifier pkg.policybanner --version install-location /Library/Security PolicyBanner.pkg

43 Scripting bash $ chmod +x buildpolicybanner.sh $./buildpolicybanner.sh pkgbuild: Inferring bundle components from contents of payload pkgbuild: Wrote package to PolicyBanner.pkg

44 Scripting bash pkgbuild --root payload --identifier pkg.policybanner --version install-location /Library/Security PolicyBanner.pkg

45 clean script continue on next line pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

46 Shebang #!/bin/bash pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

47 #! shebang sha-bang hashbang pound-bang hash-pling

48 #! who interprets the script file #!/bin/bash #!/bin/sh

49 sh vs bash minimum common shell better

50 sh is bash $ sh --version GNU bash, version (1)

51 sh is bash If bash is invoked with the name sh, it tries to mimic the startup behavior of historical versions of sh as closely as possible, while conforming to the POSIX standard as well. (bash man page)

52 sh bsh bash bash now

53

54

55

56

57 sh is bash #!/bin/sh #!/bin/bash

58 Assumptions #!/bin/bash pkgbuild --root payload \ --identifier pkg.policybanner \ assumes PATH --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

59

60 Assumptions #!/bin/bash pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

61 Assumptions #!/bin/bash /usr/bin/pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

62 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg current working directory

63 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin projectfolder=$(dirname "$0") pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

64 Assigning Variables "zeroth" argument is path to script projectfolder=$(dirname "$0")

65 Assigning Variables returns enclosing directory projectfolder=$(dirname "$0")

66 Assigning Variables projectfolder=`dirname "$0"`

67 Assigning Variables no spaces! projectfolder=$(dirname "$0")

68 Substituting Variables always quote variable substitutions pkgbuild --root "$projectfolder/payload" \

69 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin projectfolder=$(dirname "$0") pkgbuild --root payload \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

70 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin projectfolder=$(dirname "$0") pkgbuild --root "${projectfolder}/payload" \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ PolicyBanner.pkg

71 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin projectfolder=$(dirname "$0") pkgbuild --root "${projectfolder}/payload" \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ "${projectfolder}/policybanner.pkg"

72 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin pkgname="policybanner" version="1.0" projectfolder=$(dirname "$0") pkgbuild --root "${projectfolder}/payload" \ --identifier pkg.policybanner \ --version 1.0 \ --install-location "/Library/Security" \ "${projectfolder}/policybanner.pkg"

73 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin pkgname="policybanner" version="1.0" identifier="com.scriptingosx.${pkgname}" projectfolder=$(dirname "$0") pkgbuild --root "${projectfolder}/payload" \ --identifier pkg.policybanner \ --version "${version}" \ --install-location "/Library/Security" \ "${projectfolder}/policybanner.pkg"

74 Variables #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin pkgname="policybanner" version="1.0" identifier="com.scriptingosx.${pkgname}" projectfolder=$(dirname "$0") pkgbuild --root "${projectfolder}/payload" \ --identifier "${identifier}" \ --version "${version}" \ --install-location "/Library/Security" \ "${projectfolder}/${pkgname}-${version}.pkg"

75 Conditionals if [[ -e "${pkgpath}" ]]; then read -p "Package already exists! Overwrite? (y/n) " answer if [[! ${answer} == "y" ]]; then exit 1 fi fi

76 [[ ]] or [ ]

77 [ ] POSIX or sh compatible actually [ is a synonym for test weird syntax issues

78 [[ ]] only bash more resilient for empty variables and && and or boolean operators string comparison with wildcards regular expression comparison with =~

79 Conditionals if [[ -e "${pkgpath}" ]]; then read -p "Package already exists! Overwrite? (y/n) " answer if [[! ${answer} == "y" ]]; then exit 1 fi fi

80 "Simple" Script #!/bin/bash export PATH=/usr/bin:/bin:/usr/sbin:/sbin pkgname="policybanner" version="1.0" identifier="com.scriptingosx.${pkgname}" projectfolder=$(dirname "$0") pkgpath="${projectfolder}/${pkgname}-${version}.pkg" if [[ -e "${pkgpath}" ]]; then read -p "Package already exists! Overwrite? (y/n) " answer if [[! ${answer} == "y" ]]; then exit 1 fi fi pkgbuild --root "${projectfolder}/payload" \ --identifier "${identifier}" \ --version "${version}" \ --install-location "/Library/Security" \ "${pkgpath}"

81 Version Control

82 Version Control every script commit often and regularly repo is history and library share

83

84

85 Quoting

86 Quoting buildfolder=~/"my Great Project/" rm -Rf $buildfolder/*

87 Quoting buildfolder=~/"my Great Project/" rm -Rf ~/My Great Project/*

88 Quoting buildfolder=~/"my Great Project/" rm -Rf ~/My rm -Rf Great rm -Rf Project/*

89 Quoting buildfolder=~/"my Great Project/" rm -Rf $buildfolder/*

90 Quoting buildfolder=~/"my Great Project/" rm -Rf "$buildfolder"/*

91 Quoting buildfolder=~/"my Great Project/" rm -Rf "$buildfolder/*"

92 Quoting buildfolder=~/"my Great Project/" rm -Rf "$buildfolder"/*

93 Quoting buildfolder="$1" first argument rm -Rf "$buildfolder"/* $./myscript.sh "My Great Folder"

94 Quoting buildfolder="" rm -Rf ""/*

95 Quoting buildfolder="" rm -Rf /* rm: /Applications/DVD Player.app/ Contents/_CodeSignature/ CodeResources: Operation not permitted Thank you, SIP!

96 Defensive Code buildfolder="$1" rm -Rf "$buildfolder"/*

97 Defensive Code if [[ -n $1 ]]; then buildfolder="$1" rm -Rf "$buildfolder"/* else echo 'No argument' exit 1 fi

98 Defensive Code buildfolder=${1:?"no argument"} when this is unset log this and fail

99 Defensive Code buildfolder=${1:-"build"} when this is unset use this value

100 Defensive Code ${var:-"build"} default value ${var:?"no value!"} error and exit

101 Defensive Code ${var:-"build"} default value ${var:="build"} assign default ${var:?"no value!"} error and exit ${var:+"build"} overwrite

102 Defensive Code ${var:-"build"} default value ${var:?"no value!"} error and exit

103 Defensive Code buildfolder="$1" rm -Rf "$buildfolder"/*

104 Defensive Code buildfolder="${1:?'no argument'}" rm -Rf "$buildfolder"/*

105 Defensive Code if [[ -n $1 ]]; then buildfolder="$1" rm -Rf "$buildfolder"/* else echo 'No argument' exit 1 fi

106 ShellCheck

107 d Shellcheck

108 ShellCheck Line 14: read -p "Package already exists! Overwrite? (y/n) " answer ^-- SC2162: read without -r will mangle backslashes. Line 24: ${pkgpath} ^-- SC2086: Double quote to prevent globbing and word splitting.

109 Strict Mode set -euo pipefail

110 Strict Mode set -e fail on non-zero command set -u fail on unset variables set -o pipefail any element of a pipe chain fails

111 Trace Mode set -x Trace Mode

112 Trace Mode $ bash -x buildpolicybannerpkg.sh + export PATH=/usr/bin:/bin:/usr/sbin:/sbin + PATH=/usr/bin:/bin:/usr/sbin:/sbin + pkgname=policybanner + version=1.0 + identifier=com.scriptingosx.policybanner ++ dirname buildpolicybannerpkg.sh + projectfolder=. + pkgpath=./policybanner-1.0.pkg + [[ -e./policybanner-1.0.pkg ]] + read -p 'Package already exists! Overwrite? (y/n) ' answer Package already exists! Overwrite? (y/n) y + [[! y == \y ]] + pkgbuild --root./payload --identifier com.scriptingosx.policybanner --version install-location /Library/Security./ PolicyBanner-1.0.pkg pkgbuild: Inferring bundle components from contents of./payload pkgbuild: Wrote package to./policybanner-1.0.pkg

113 Trace Mode set -x bash -x script.sh

114 Trace Mode set -x... set +x

115 bash vs everything else

116 bash Pros everywhere process control, file management tools awk, sed, grep, networksetup, systemsetup, scutil, pmset, dscl, sysadminctl, etc.

117 bash Pros documentation examples resources community

118 bash Cons data types: dict, array (bash4) complex data files: plist, xml, json User Interaction

119 AppleScript Swift

120 AppleScript Pros inter application data communication (where supported) FileMaker, Adobe, MS Office, etc. Simple UI: dialogs, alerts, notifications

121 AppleScript Cons usually requires user logged in troublesome when running as root Future?

122

123 bash + AppleScript $ osascript -e 'display alert "Hey!"'

124 bash + AppleScript $ osascript -e 'display notification "Hey!"'

125 bash + AppleScript Use Bash "Here Files" to include longer AppleScripts # prints the path of the front Finder window open function pwdf () { osascript <<EndOfScript tell application "Finder" if (count of Finder windows) is 0 then set dir to (desktop as alias) else set dir to ((target of Finder window 1) as alias) end if return POSIX path of dir end tell EndOfScript

126 bash + AppleScript Use osascript shebang #!/usr/bin/osascript on run arguments tell application "Finder" -- no argument: get frontmost window or desktop if (count of arguments) is 0 then if (count of windows) is 0 then set dir to (desktop as alias) else set dir to ((target of Finder window 1) as alias) end if else if first item of arguments is in {"-all", "-a"} then

127 bash + AppleScript Use osascript shebang to write #!/usr/bin/osascript on run arguments tell application "Finder" -- no argument: get frontmost window or desktop if (count of arguments) is 0 then if (count of windows) is 0 then set dir to (desktop as alias) else set dir to ((target of Finder window 1) as alias) end if else if first item of arguments is in {"-all", "-a"} then

128 AppleScript + bash

129 AppleScript Swift

130 Python Pros comparatively easy learning curve complex data objects: dict, list complex files: xml, plist, json cross-platform

131 Python Bridge Cocoa/Objective-C Bridge from Foundation import CFPreferencesCopyAppValue print CFPreferencesCopyAppValue("idleTime", "com.apple.screensaver")

132

133 Python Cons access to Cocoa libraries steep learning curve bridge can be finicky

134 AppleScript Swift

135 Swift Pros "native" language to macos interpreted, Playgrounds and compiled complex data types, control structures xml, plist and json (Swift 4) native Apps (Mac and ios)

136 Swift Pros #!/usr/bin/swift -swift-version 3 import Foundation let samplepath = "../examples" let dictpath = "\(samplepath)/berry.plist" if let sampledict = NSDictionary(contentsOfFile: dictpath) { for (key, value) in sampledict { print("\(key) = \(value)") } } else { print("couldn't read: \(dictpath)") }

137 Swift Cons complex object-oriented language moving target (Swift 1, 2, 3, 3.1, 3.2, 4)

138 (not a complete list) AppleScript Swift

139 Scripting bash

140 Scripting bash Automate (even simple things) Embrace bash Quote Write Defensive Code Use Version Control

141 Further Learning tldp.org/ldp/abs/html

142 scriptingosx.com/bash

143 Scripting OS X Armin Briegel Mac Admin, Consultant and Author scriptingosx