Redirecting a List of Qshell Commands

Published: September 20, 2006

Hey, Ted:

I need a little help with a Qshell script. I retrieve a list of IFS files that have a certain extension (a suffix precede by a period) and pipe the list into another process. Now I have to also include other files that have a completely different extension. I do not want to run the command twice, processing each type of file in turn. How do I redirect the output of more than one command into one output stream?

--Brad

OK, let's set up the problem for the benefit of the readers. Suppose Brad's script currently processes files with the extension .TXT. Case of the extension is immaterial.

ls *.[Tt][Xx][Tt] | sort -f > somefile

Now he has to include .CSV files as well. The solution is to replace the single ls command with a list of commands. Just follow these easy steps.

• Precede the first one in the list with an opening brace and a space
• Terminate each command with a semicolon
• Conclude the list with a closing brace

Brad's new command is the following:

{ ls *.[Tt][Xx][Tt]; ls *.[Cc][Ss][Vv]; } | sort -f > somefile

All of the TXT and CSV files will be directed to the sort routine as one input stream.

The braces force Qshell to process the commands concurrently. I have used the ls command in this illustration, but you may use any command that writes to standard output.

--Ted