How to run a Unix shell script from the Mac Finder

If you ever want to create a Unix shell script that you can give to someone else so they can double-click it and run it through the Mac OS X Finder, all you have to do is (a) name the file with the ".command" extension and (b) make it executable. So, just name your Mac/Unix script like this:


Then make it executable, like this:

chmod +x ShowProcesses.command

You can also leave out the usual #!/bin/sh part on the first line.

Setting the classpath in a Scala script (Scala shell script)

Scala script FAQ: How do I set the CLASSPATH in a Scala shell script?

If you need to set the CLASSPATH when executing a Scala script, use the exec command as shown in the following example:

exec scala -classpath "lib/htmlcleaner-2.2.jar:lib/scalaemail_2.9.1-1.0.jar:lib/stockutils_2.9.1-1.0.jar" "$0" "$@"

As you can see from that code, I'm adding three jar files to my classpath at the beginning of my Scala shell script.

A Perl script to print Nagios log records in a human readable date format

Perl date FAQ: Can you share a Perl date example where you print a date in a decent human-readable format?

Update: Be sure to look at the comments below for some great Perl "one liners", i.e., one-line solutions to this problem.

In this blog I'll share the source code for a Perl program that takes nagios.logrecords as input, then outputs the records with a human-readable date format. More specifically, the input records look like this:

Reading Scala command line arguments

Scala command line FAQ: How do I read command line arguments (args) in a Scala shell script?

If your Scala shell script is very short, and you're not using an object or class declaration -- i.e., you have no main method -- you can access the script's command line arguments through the default args array, which is made available to you by Scala.

For instance, you can create a one-line Scala script named hello.scala like this:

Ruby command line arguments

Ruby FAQ: How do I read command line arguments in a Ruby script (Ruby command line args)?

To read command line args in a Ruby script, use the special Ruby array ARGV to get the information you need. Here are a few examples.

1) Getting the number of command line args

To get the number of command line arguments passed in to your Ruby script, check ARGV.length, like this:

Handling spaces in Linux shell script input (and for loops)

Linux shell script FAQ: How can I deal with spaces (blank spaces) in my input data when I'm writing a shell script for loop or while loop?

I was just working on a Linux shell script, and ran into the ages-old problem of handling data that has spaces (space characters) in it. I run into this any time I try to read a data file with blank spaces in it, or when I run into files and directories with spaces in their names. Whenever I try to work this data like this in a shell script for loop, the spaces always ruin what I'm trying to accomplish.

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