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;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 Show Sample Output


    23
    true && { echo success;} || { echo failed; }
    clockworkavian · 2009-04-02 01:49:25 13
  • 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


    6
    whiptail --checklist "Simple checkbox menu" 11 35 5 tag item status repeat tags 1
    clockworkavian · 2009-03-30 12:21:48 8
  • 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


    1
    function fork () { tf=$(tempfile -d /tmp -p $1.);echo -n "$tf "; $@ &>$tf& }
    clockworkavian · 2009-03-25 23:33:54 7
  • Depending on the network setup, you may not get the hostname. Show Sample Output


    4
    nmap 192.168.0-1.0-255 -sP
    clockworkavian · 2009-03-23 22:19:05 10

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Open a manpage in the default (graphical) web browser
An easy alias for opening a manpage, nicely HTML formatted, in your set internet browser. If you get a "command exited with status 3" error you need to install groff.

To create files with specific permission:

Dump audio from video without re-encoding.
This removes the video and subsequent file size and directly copies the audio.

Clean all .pyc files from current project. It cleans all the files recursively.

check for write/read permissions
su www-apache/ftp user and then check readable: find ~/ -type d \( -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' \) -prune -o -exec test -r {} \; -exec echo {} readable \; 2>/dev/null check writable: find ~/ -type d \( -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' \) -prune -o -exec test -w {} \; -exec echo {} writable \; 2>/dev/null

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"

tar exclude files or directories
If you want to exclude only one file or directory you should use as --exclude=file_or_directory

Terrorist threat level text

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Count items in JSON array
Pipe any JSON to jq, then count with the appropiate expression and use the | length on the array


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