files

Here's a shell script that I use that search Java jar files for any type of pattern. You can use it to search for the name of a class, the name of a package, or any other string/pattern that will show up if you manually ran jar tvf on each jar file. The advantage of this script -- if you're a Unix, Linux, or Cygwin user -- is that this script will search through all jar files in the current directory.

This morning I decided to take a few minutes to backup all the songs I've purchased over the last half-year. These are all on my Mac OS X system, under the Music folder in my home directory.

The problem with trying to do this with standard Unix tools is that all these subdirectories and filenames have spaces in their names. Just looking at the Music folder, it contains many directory names like this:

sed command FAQ: How can I use the Unix/Linux sed command to edit (modify) files in place?

The short answer is that you just need to use the -i or --in-place sed arguments, as shown in the sed man page:

-i[SUFFIX], --in-place[=SUFFIX]

edit files in place (makes backup if extension supplied)

Then, if you have a file named 'hello.txt' with contents like this:

jello, world
this is a test

you can then run a sed command like this to modify that file:

Unix/Linux find "patterns" FAQ: How do I find files or directories that don't match a specific pattern (files not matching a regex pattern, or filename pattern)?

In my case I just ran into a situation where I needed to find all files below the current subdirectory that are NOT named with the filename pattern "*.html" . Fortunately with the newer Unix/Linux find syntax this solution is pretty easy, you just include the "-not" argument, like this:

Unix/Linux chown FAQ: How do I use the chown command?

The chown command is most commonly used by Unix/Linux system administrators who need to fix a permissions problem with a file or directory, or many files and many directories.

For instance, suppose you want files to be owned by the user "nobody", but when you issue an ls command, you see that they're owned by the user "fred", like this: