Commands by Hello8055 (0)

  • bash: commands not found

What's this? 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.

Share Your Commands

Check These Out

Converting video file (.flv, .avi etc.) to .3gp
ffmpeg -i = input file name -s = set frame size, qcif=176x144 -vcodec = force video codec -r = frame-rate [default = 25] -b = bit-rate [200 kb/s] -acodec = force audio codec -ab = audio bitrate in bits/s [64k] -ac = no. of audio channels [1] -ar = audio sampling frequency [44100 Hz] optional: -sameq = use same video quality as source (implies VBR) -f = force format -y = overwrite output files

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" }

Printable random characters
Reads psuedorandom bytes from /dev/urandom, filtering out non-printable ones. Other character classes can be used, such as [:alpha:], [:digit:] and [:alnum:]. To get a string of 10 lowercase letters: $ tr -dc '[:lower:]' < /dev/urandom | head -c 10

Key binding to search
This is a simple bash function and a key binding that uses commandlinefu's simple and easy search API. It prompts for a search term, then it uses curl to search commandline fu, and highlights the search results with less.

Join lines
It's works only when you replace '\n' to ONE character.

MySQL dump restore with progress bar and ETA
Display a progress bar while restoring a MySQL dump.

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"

Test network speed without wasting disk
The above command will send 4GB of data from one host to the next over the network, without consuming any unnecessary disk on either the client nor the host. This is a quick and dirty way to benchmark network speed without wasting any time or disk space. Of course, change the byte size and count as necessary. This command also doesn't rely on any extra 3rd party utilities, as dd, ssh, cat, /dev/zero and /dev/null are installed on all major Unix-like operating systems.

Remove invalid key from the known_hosts file for the IP address of a host
Quick shortcut if you know the hostname and want to save yourself one step for looking up the IP address separately.

Create date-based tgz of current dir, runs in the background, very very cool
This is freaking sweet!!! Here is the full alias, (I didn't want to cause display problems on's homepage): $ alias tarred='( ( D=`builtin pwd`; F=$(date +$HOME/`sed "s,[/ ],#,g"

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: