Commands by clockworkavian (4)

  • 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; }|| { echo failed;; } 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 Show Sample Output

    true && { echo success;} || { echo failed; }
    clockworkavian · 2009-04-02 01:49:25 2
  • Not so much handy by itself, but very nice in shell scripts. This makes you a handy ncurses based checklist. Much like terminal installers, just use the arrow keys and hit 'Space' to adjust the selections. Returns all selected tags as strings, with no newline at the end. So, your output will be something like: "one" "two" "three" "four" "etc" For those who prefer bash expansion over gratuitious typing: whiptail --checklist "Simple checkbox menu" 12 35 3 $(echo {one,two,three,four}" '' 0"} ) Things to note: The height must includes the outer border and padding: add 7 to however many items you want to show up at the same time. If the status is 1, it will be selected by default. anything else, will be deselected. Show Sample Output

    whiptail --checklist "Simple checkbox menu" 11 35 5 tag item status repeat tags 1
    clockworkavian · 2009-03-30 12:21:48 3
  • This function runs a program in the background, and logs all output to an automatically created logfile. That way, you can still get at the output without it clogging up your terminal. Tip: Throw fork() and this: for prog in firefox kate konqueror ;do alias $prog="fork $prog";done into your bashrc, so that they'll automatically run out of the way. Show Sample Output

    function fork () { tf=$(tempfile -d /tmp -p $1.);echo -n "$tf "; $@ &>$tf& }
    clockworkavian · 2009-03-25 23:33:54 3
  • Depending on the network setup, you may not get the hostname. Show Sample Output

    nmap 192.168.0-1.0-255 -sP
    clockworkavian · 2009-03-23 22:19:05 5

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Find the package that installed a command

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Determine command type (alias, keyword, function, builtin, or file)
Prints a string indicating whether a command is an alias, keyword, function, builtin, or file. I have used this in my BASH scripts to allow an external parameter to define which function to run, and ensure that it is a valid function that can indeed be run.

Convert file type to unix utf-8
converts encoding of a file to unix utf-8 useful for data files that contain what would be usable ascii text but are encoded as mpeg or some other encoding that prevents you from doing common manipulations like 'sed'

See system users

Convert text to lowercase
Usage: lower [STRING]...

Attach screen over ssh
Directly attach a remote screen session (saves a useless parent bash process)

list all executables in your path
If run in bash, this will display all executables that are in your current $PATH

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Merge various PDF files

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