added concrete example to readme

Signed-off-by: Konstantin Läufer <[email protected]>

README.md

@@ -29,31 +29,78 @@
 This is a Scala-based solution to the
 [process tree homework assignment](http://osdi.etl.luc.edu/homework/home-lab-assignment-1)
 from the course
-[COMP 374/410: Introduction to Operating Systems](http://osdi.etl.luc.edu).
+[COMP 374/410: Introduction to Operating
+Systems](http://osdi.etl.luc.edu).
+
+In short, this program converts a flat list of current processes, as printed by the `ps` command
+
+```
+> ps -ef
+  UID   PID  PPID   C STIME   TTY           TIME CMD
+    0     1     0   0 24Aug23 ??        72:25.36 /sbin/launchd
+    0   102     1   0 24Aug23 ??        26:34.38 /usr/libexec/logd
+    0   103     1   0 24Aug23 ??         0:01.08 /usr/libexec/smd
+...
+  502 60706 60704   0 10:53PM ??         0:02.27 /Applications/WhatsApp.app/...
+...
+  502 65138   735   0 10:48AM ??         0:23.83 /Applications/Microsoft Edge.app/...
+...
+```
+
+to a hierarchical process tree, as printed by the `pstree` command (you'd usually have to install this through your package manager).
+
+```
+> pstree
+-+= 00001 root /sbin/launchd
+ |--= 00102 root /usr/libexec/logd
+ |--= 00103 root /usr/libexec/smd
+ .
+ .
+ .
+ |-+= 00735 laufer /Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge
+ | |--- 65138 laufer /Applications/Microsoft Edge.app/Contents/Frameworks/Microsoft Edge
+ .
+ .
+ .
+ |-+= 60704 laufer /Applications/WhatsApp.app/...
+ | |--- 60706 laufer /Applications/WhatsApp.app/...
+ .
+ .
+ .
+```
+
 
 # Usage
 
 To run the tests:
 
-    $ sbt test
+```
+$ sbt test
+```
 
 To run the main methods:
 
-    $ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.mutable.Main"
-    $ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.groupby.Main"
-    $ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.fold.Main"
+```
+$ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.mutable.Main"
+$ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.groupby.Main"
+$ ps -ef | sbt "runMain edu.luc.etl.osdi.processtree.scala.fold.Main"
+```
 
 To generate larger data sets for testing:
 
-    $ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fakeps.Main 100000" > data.txt
+```
+$ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fakeps.Main 100000" > data.txt
+```
 
 To run the benchmarks:
 
-    $ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fakeps.Benchmark"
-    $ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.mutable.Benchmark"
-    $ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.groupby.Benchmark"
-    $ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fold.Benchmark"
+```
+$ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fakeps.Benchmark"
+$ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.mutable.Benchmark"
+$ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.groupby.Benchmark"
+$ sbt "test:runMain edu.luc.etl.osdi.processtree.scala.fold.Benchmark"
+```
 
 On Windows, if you installed [Git](http://git-scm.com/) with the recommended
 third option, *Use Git and optional Unix tools from the Windows Command Prompt*,
-then you will have a `ps` command available.
+then you will have a `ps` command available.