Home / server / Questions / 268957
Accepted
RonK
Asked: 2011-05-13 02:34:27 +0800 CST

How to iterate over a list of files and perform an action on them

  • 772

I want to write a script (or preferably an alias) that does the following:

  1. Find all the files matching a pattern *.jar
  2. Iterate over all those files, and run jar tvf <jar file name> | grep <Some argument>
  3. Print if a jar contains a file with a name that matches the argument

I'm working on tcsh and would prefer not to open a new shell since I want this as an alias and not a script - is it doable?

command-line-interface shell-scripting

2 Answers

  1. Best Answer

    A straight alias isn't going to work for this application. Something like this would come close, except what you would get is the output of the grep, not the jar filename:

    alias targrep="find . -name '*.jar' -exec jar tvf {} \; | grep"

targrep someterm

    To get the filename, you should switch to using a function instead of an alias so that you have more control over arguments and where values go. (Note: bash format, you may need to modify for tcsh)

    function jargrep () {
    find . -name '*.jar' | while read jar; do
        jar tvf $jar | grep -q  $@ && echo $jar
    done
}

jargrep someterm
    • 3

  2. Try something along the lines of 

    find . -name '*.jar' -exec 'jar tvf | grep <some agrument>'

    read the man page for find for more details.

    • -1