Download as PPTX
![exercise: using pipes
● write a program that mimics grep
– e.g. grep groovy < input.txt
● read lines from System.in
– hint: use eachLine
● print line if it contains the argument
– hint: use args[0]](https://image.slidesharecdn.com/groovyshellscriptinggr8conf-190529122322/75/Groovy-shell-scripting-10-2048.jpg)
![final assignment - hints
● Isolated tests:
– Map coercion for mocks:
[methodName: { … }] as Interface
– @Grab Mockito for mocks
● integrated tests:
– getInputStream() on Process
– getOutputStream() on Process
●](https://image.slidesharecdn.com/groovyshellscriptinggr8conf-190529122322/75/Groovy-shell-scripting-20-2048.jpg)
![got interested?
● Previous work: Sascha Klein - “Groovy on the Shell”
– https://tinyurl.com/groovy-on-the-shell
● Georg Berky - “Groovy Shell Scripting”
(Never Code Alone Blog)
– http://tinyurl.com/groovy-shell-1
– http://tinyurl.com/groovy-shell-2
– http://tinyurl.com/groovy-shell-3
Videoplasty.com [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]](https://image.slidesharecdn.com/groovyshellscriptinggr8conf-190529122322/75/Groovy-shell-scripting-21-2048.jpg)
Uploaded byGeorg Berky
Groovy shell scripting
The document outlines a journey to using Groovy for shell scripting, detailing programming interests, tools, and techniques. It includes practical exercises on using pipes, dependency management, and testing in Groovy scripts. Additionally, it provides resources and references for further learning about Groovy and related technologies.
![Vibe Coding vs. Spec-Driven Development [Free Meetup]](https://cdn.slidesharecdn.com/ss_thumbnails/vibecodingvsspecdrivendevelopment-251209105622-43f455e7-thumbnail.jpg?width=640&height=640&fit=bounds)
Groovy shell scripting
- 1. Making shell scriptsGroovy
- 2. about me ● programmer+ DevOps enthusiast – Java, Groovy, learning Clojure – Linux, Ansible, Liquibase, Maven ● co-organizing software craftsmanship groups: – Ruhrgebiet + Düsseldorf (Germany) – coderetreats, coding dojos georgberky [email protected]
- 3. my journey toGroovy ● problem in production ● when contacting a remote system via HTTP ● not enough logging ● but access to the machine ● everything works in curl
- 4. my journey toGroovy ● problem has to be inside the JVM ● google: “run Java as a script” ● Groovy! ● some tinkering, some dependencies ● ⇒ missing certificate in Java’s keystore :)
- 5. today’s agenda ● shebang+ groovyserver ● pipes ● dependency management ● parameter parsing ● external commands ● bonus: XML/JSON ● bonus: FIFOs ● bonus: logging
- 6. setup ● install sdkmanfrom sdkman.io ● install groovy using sdkman – groovy --version should work ● use your favorite editor ● Groovy API http://docs.groovy-lang.org/latest/html/gapi/ ● JDK extensions: http://groovy-lang.org/gdk.html
- 7. getting started ● startwith shebang + make executable ● write “hello world” in Java ● use file extension: .groovy ● run: ./HelloWorld.groovy ● leave out as many syntax elements as you can
- 8. pipes ● connect twoprocesses ● live outside your root file system ● lifetime: as long as the process creating it ● writing end + reading end ● ends support UNIX file interface
- 9. protocol for pipes ●one line is one message ● line buffered ● last producer disconnects: EOF ● preserve order
- 10. exercise: using pipes ●write a program that mimics grep – e.g. grep groovy < input.txt ● read lines from System.in – hint: use eachLine ● print line if it contains the argument – hint: use args[0]
- 11. testing ● batteries included:JUnit 3 – 5 ● power assert ● test doubles: closure + map coercion ● MockFor, StubFor only in dynamic context scripts: compiled
- 12. exercise: testing ● FizzBuzzKata ● print all numbers from 1 to 100 ● if n divisible by 3, print fizz ● if n divisible by 5, print buzz ● if n divisible by 3 and 5, print fizzbuzz
- 13. dependency management ● @Grab(‘org.apache.commons:commons-lang3:3.9’) ●@Grab(group='org.apache.commons', module='commons-lang3', version='3.9') ● at runtime: Grape.grab( group:’org.apache.commons’, module:’commons-lang3’, version:’3.9’)
- 14. dependency management ● GroovyGrape ● built on top of Apache Ivy ● grabs (transitive) dependencies – default: from Maven Central ● scripts: replaced with Grape.grab() – in static initializer
- 15. command line options ●Groovy Commons CliBuilder ● @Grab(group='org.codehaus.groovy', module='groovy-cli-commons', version='2.5.7') ● import groovy.cli.commons.CliBuilder ● supports short and long options ● now supports typed arguments
- 16. exercise: parsing arguments ●use: @Grab(group='org.codehaus.groovy', module='groovy-cli-commons', version='2.5.7') ● extend your grep script: ● ignore case: -i ● invert matching: -v
- 17. external commands ● methodexecute() on String ● e.g. “ls -1”.execute() ● creates and runs instance of Process ● method getText() on Process, then method eachLine() on String
- 18. final assignment ● Producer:prints numbers, one per line ● Consumer: read lines – increment the number – print the incremented number ● communicate via pipe ● separate concerns ● test drive as much as you can
- 19.
- 20. final assignment -hints ● Isolated tests: – Map coercion for mocks: [methodName: { … }] as Interface – @Grab Mockito for mocks ● integrated tests: – getInputStream() on Process – getOutputStream() on Process ●
- 21. got interested? ● Previouswork: Sascha Klein - “Groovy on the Shell” – https://tinyurl.com/groovy-on-the-shell ● Georg Berky - “Groovy Shell Scripting” (Never Code Alone Blog) – http://tinyurl.com/groovy-shell-1 – http://tinyurl.com/groovy-shell-2 – http://tinyurl.com/groovy-shell-3 Videoplasty.com [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
- 22.