Check These Out
This will perform one of two blocks of code, depending on the condition of the first. Essentially is a bash terniary operator.
To tell if a machine is up:
$ ping -c1 machine { echo succes;} || { echo failed; }
Because of the bash { } block operators, you can have multiple commands
$ ping -c1 machine && { echo success;log-timestamp.sh }|| { echo failed; email-admin.sh; }
Tips:
Remember, the { } operators are treated by bash as a reserved word: as such, they need a space on either side.
If you have a command that can fail at the end of the true block, consider ending said block with 'false' to prevent accidental execution
I often use it to find recently added ou removed device, or using find in /dev, or anything similar.
Just run the command, plug the device, and wait to see him and only him
Turns a PDF into HTML (without images) and prints it to the standard out which is picked up and interpreted by w3m.
Using this command you can track a moment when usb device was attached.
This assumes you have the package installed necessary for converting WMF files. On my Ubuntu box, this is libwmf-bin. I used this command, as libwmf is not on my wife's iMac, so I archived the directories containing the WMF files from OS X, ran them on my Ubuntu box, archived the resulting SVGs, and sent them back to her. Quick, simple and to the point.
Searches directories recursively looking for extensions ignoring case. This is much more readable and clean than -exec for find. The while loop also gives further flexibility on complex logic. Also, although there is 'wmf2svg --auto', it expects lowercase extensions, and not uppercase. Because I want to ignore case, I need to use the -o option instead.
Works in ZSH and BASH. Haven't tested in other shells.
This is an alternative to another command using two xargs. If it's a command you know there's only one of, you can just use:
$ ls -l /proc/$(pgrep COMMAND)/cwd
Sniffing traffic on port 80 only the first 1500 bytes
As of March 7, 2012:
$ brew update - downloads upgraded formulas
$ brew upgrade [FORMULA...] - upgrades the specified formulas
$ brew outdated - lists outdated installations
Note updating all packages may take an excruciatingly long time. You might consider a discriminating approach: run `brew outdated` and select specific packages needing an upgrade.
For more information see homebrew's git repository: https://github.com/mxcl/homebrew