Commands by toddkaufmann (1)

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commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Command line calculator
This function defines a command line calculator that handles everything pythons math module can handle, e.g. trigonometric functions, sqrt, log, erf, ... (see http://docs.python.org/library/math.html). It even knows about the constants pi and e.

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"

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" }

ZSH prompt. ':)' after program execution with no error, ':(' after failure.
sorry for my english

Target a specific column for pattern substitution
Awk replaces every instance of foo with bar in the 5th column only.

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" }

Use GNU info with a pager
This makes GNU info output menu items recursively and pipe its contents to less, allowing one to use GNU info in a manner similar to 'man'.

Rename files in batch

Download Apple movie trailers
Copy the link to an HD movie trailer in to this command. It's more eleganant if it's put in a to a script, taking the URL as input.

Open a file in a GTK+ dialog window
I use zenity because it's a rewrite of gdialog and also replaces gmessage and has more useful options. Using --text-info allows you to select and copy the text to your clipboard. To see a file in a list dialog: cat /etc/passwd | zenity --width 800 --height 600 --list --column Entries If you don't have zenity, you'll have to download it via apt-get install zenity, etc.

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