These exercises are meant to further demonstrate what sed can do.

  1. Print a list of files in your scripts directory, ending in .sh. Mind that you might have to unalias ls. Put the result in a temporary file.

  2. Make a list of files in /usr/bin that have the letter a as the second character. Put the result in a temporary file.

  3. Delete the first 3 lines of each temporary file.

  4. Print to standard output only the lines containing the pattern an.

  5. Create a file holding sed commands to perform the previous two tasks. Add an extra command to this file that adds a string like *** This might have something to do with man and man pages *** in the line preceding every occurence of the string man. Check the results.

  6. A long listing of the root directory, /, is used for input. Create a file holding sed commands that check for symbolic links and plain files. If a file is a symbolic link, precede it with a line like --This is a symlink--. If the file is a plain file, add a string on the same line, adding a comment like <--- this is a plain file.

  7. Create a script that shows lines containing trailing white spaces from a file. This script should use a sed script and show sensible information to the user.