Suppose that you had change in a directory like /home/user/mycode/code, and now you need to list it, instead of type entire path again, use ls !$ to recall path and list. Useful with many commands, this is only an example. (In this case, same result can be achivied with ls .)

Remove blank lines from files, even if some of the lines have whitespace (spaces, tabs, etc.). Also creates a .bak copy of the original file. Works on Mac also.

Thanks to those all those who left comments.

I needed this for wine.

That will open vi with the four README files in different viewports.

Specially handy when you find there is only one file matching your pattern and you don't want to specify the full path.

Add this to .bashrc, then you can quickly create backups from files on current directory, but it only backups files on current directory.

useful when changing config files, coding something or just trying something stupid.

Adds the stdout (standard output) to the beginning of logfile.txt. Change "command" to whatever command you like, such as 'ls' or 'date', etc. It does this by adding the output to a temporary file, then adding the previous contents of logfile.txt to the temp file, then copying the new contents back to the logfile.txt and removing the temp file.

It will return a ranked list of your most commonly-entered commands using your command history

Remove all hidden files in a directory excluding current dir . and parent dir .. with .??* that means files with at least two characters.

enlubtsqyuse

subsequently

If you don't want to commit files to subversion, and don't want those file to show up when doing an "svn stat", this command is what you need

Does that count as a win for bzip2?

Replace "en1" with your network interface (on OS X, usually en0, en1, eth0, etc..)

This will merge all of the changes from {rev_num} to head on the branch to the current working directory

get cpu info from dmesg

After seeing the command you wish to repeat, just invoke it using the ! syntax.

ncal -e shows the date of Easter this year. ncal -e YYYY shows the date of Easter in a given year. ncal -o works the same way, but for Orthodox dates.

Shows all linked file and destinations. The 'ls -l' command lists the files in long (1 file per line) format, and the grep command displays only those lines that starts with an l (lower case L) -- a linked file.

Updated: Remove reference to hard links because this command does not apply to hard link as others kindly pointed out.