CODEWITHSUNDEEP
scala
Daniel
Daniel

Reputation: 6039

Run console command in scala

I want to run this command in Scala, although I am facing all sorts of errors: 

sed -i '.back' 's/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g' /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf

or 

sed -i '.back' "s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g" /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf

I have listed all my tries here (none works). What is the right way to run this command?

Try 1: 

scala> val command = "sed -i '.back' 's/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g' /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf"
scala> command.! 
sed: 1: "'s/maxTablesPerQuestion ...": invalid command code '
res25: Int = 1

Try 2: with double quotations: 

scala> val command = "sed -i '.back' \"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\" /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf"
scala> command.! 
sed: 1: ""s/maxTablesPerQuestion ...": invalid command code "
res26: Int = 1

Try 3: With Seq: 

scala> val command = Seq("sed -i '.back' \"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\" /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf")
scala> command.! 
java.io.IOException: Cannot run program "sed -i '.back' "s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g" /Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf": error=2, No such file or directory
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
  at scala.sys.process.ProcessBuilderImpl$Simple.run(ProcessBuilderImpl.scala:69)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.run(ProcessBuilderImpl.scala:98)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.$bang(ProcessBuilderImpl.scala:112)
  ... 33 elided
Caused by: java.io.IOException: error=2, No such file or directory
  at java.lang.UNIXProcess.forkAndExec(Native Method)
  at java.lang.UNIXProcess.<init>(UNIXProcess.java:248)
  at java.lang.ProcessImpl.start(ProcessImpl.java:134)
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
  ... 36 more

Try 4: with Seq: 

scala> val command = Seq("sed -i '.back' \"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\"", "/Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf")

scala> command.!
java.io.IOException: Cannot run program "sed -i '.back' "s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g"": error=2, No such file or directory
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
  at scala.sys.process.ProcessBuilderImpl$Simple.run(ProcessBuilderImpl.scala:69)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.run(ProcessBuilderImpl.scala:98)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.$bang(ProcessBuilderImpl.scala:112)
  ... 33 elided
Caused by: java.io.IOException: error=2, No such file or directory
  at java.lang.UNIXProcess.forkAndExec(Native Method)
  at java.lang.UNIXProcess.<init>(UNIXProcess.java:248)
  at java.lang.ProcessImpl.start(ProcessImpl.java:134)
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
  ... 36 more

Try 5: with Seq:

scala> val command = Seq("sed -i '.back'", "\"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\"", "/Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf")

scala> command.!
java.io.IOException: Cannot run program "sed -i '.back'": error=2, No such file or directory
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
  at scala.sys.process.ProcessBuilderImpl$Simple.run(ProcessBuilderImpl.scala:69)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.run(ProcessBuilderImpl.scala:98)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.$bang(ProcessBuilderImpl.scala:112)
  ... 33 elided
Caused by: java.io.IOException: error=2, No such file or directory
  at java.lang.UNIXProcess.forkAndExec(Native Method)
  at java.lang.UNIXProcess.<init>(UNIXProcess.java:248)
  at java.lang.ProcessImpl.start(ProcessImpl.java:134)
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
  ... 36 more

Try 6: 

scala> val command = Seq("sed -i", "'.back'", "\"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\"", "/Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf")

scala> command.!
java.io.IOException: Cannot run program "sed -i": error=2, No such file or directory
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
  at scala.sys.process.ProcessBuilderImpl$Simple.run(ProcessBuilderImpl.scala:69)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.run(ProcessBuilderImpl.scala:98)
  at scala.sys.process.ProcessBuilderImpl$AbstractBuilder.$bang(ProcessBuilderImpl.scala:112)
  ... 33 elided
Caused by: java.io.IOException: error=2, No such file or directory
  at java.lang.UNIXProcess.forkAndExec(Native Method)
  at java.lang.UNIXProcess.<init>(UNIXProcess.java:248)
  at java.lang.ProcessImpl.start(ProcessImpl.java:134)
  at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
  ... 36 more

Try 7: with Seq: 

scala> val command = Seq("sed", "-i", "'.back'", "\"s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g\"", "/Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf")

scala> command.!
sed: 1: ""s/maxTablesPerQuestion ...": invalid command code "
res34: Int = 1

Upvotes: 2

Views: 1831

Answers (1)

marios
marios

Reputation: 8996

The best way to execute system commands in Scala is to use the "Sequence syntax" (see code). The long string with escape characters is much more tedious to get right. I almost never had any issues when using this syntax.

One thing to note is that you no longer need to use the single ' or double quotes " to define the segments of your command. The sequence already gives all the details needed to the sed (or any other command).

Give it a try, let me know if it doesn't do exactly what you needed.

import sys.process._

Seq("sed","-i",".back","s/maxTablesPerQuestion/maxTablesPerQuestion = 2.0 /g", "/Users/i-danielk/ideaProjects/aristo/solvers/tableilp/src/main/resources/application.conf").!

Upvotes: 4

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