Save the current directory without having to leave it. When you do decide to leave the current directory, use popd to return to it.

If you just executed some long command, like "ps -aefww | grep -i [m]yProcess", and if you don't want to retype it or cycle backwards in history and waste time quoting it, then you can use history substitution.

For those who don't have the symlinks command, you can use readlink. This command is not straightforward because readlink is very picky. The backslash in front of 'ls' means not to use an alias (e.g. color escape codes from an aliased 'ls' could mess up readlink), and the -1 (one) means to print the entries separated by newlines. xargs -l (the letter L) means to process each input separated by newlines as separate commands.

Deletes files older than "n" minutes ago. Note the plus sign before the n is important and means "greater than n". This is more precise than atime, since atime is specified in units of days. NOTE that you can use amin/atime, mmin/mtime, and cmin/ctime for access, modification, and change times, respectively. Also, using -delete is faster than piping to xargs, since no piping is needed.

The pstack command prints a stack trace of running processes without needing to attach a debugger, but what about core files? The answer, of course, is to use this command. Usage: gdbbt program corefile