Commands by carlesso (2)

  • This is useful for example if you are on ssh in a server and the server goes down without letting you out. This is part of a larget sets of escape sequences provided by ssh. You can find them with ~? Here's the list: ~. - terminate connection (and any multiplexed sessions) ~B - send a BREAK to the remote system ~C - open a command line ~R - request rekey ~V/v - decrease/increase verbosity (LogLevel) ~^Z - suspend ssh ~# - list forwarded connections ~& - background ssh (when waiting for connections to terminate) ~? - this message ~~ - send the escape character by typing it twice (Note that escapes are only recognized immediately after newline.) Show Sample Output


    11
    <Return>~.
    carlesso · 2013-06-26 13:34:58 0
  • Useful if you have a list of images called 1 2 3 4 and so on, you can adapt it to rewrite it as 4 (in this example) 0-padded number. Show Sample Output


    5
    for i in ???.jpg; do mv $i $(printf %04d $(basename $i .jpg) ).jpg ; done
    carlesso · 2010-11-18 23:48:41 0

What's this?

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.

Share Your Commands


Check These Out

Silently Execute a Shell Script that runs in the background and won't die on HUP/logout
This command runs your shell script in the background with no output of any kind, and it will remain running even after you logout.

Convert JSON to YAML
Convert JSON to YAML. Note that you'll need to have PyYaml installed.

Remove a line in a text file. Useful to fix
In this case it's better do to use the dedicated tool

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" }

grep for minus (-) sign
Use flag "--" to stop switch parsing

The Chronic: run a command every N seconds in the background
Chronic Bash function: $ chronic 3600 time # Print the time in your shell every hour $ chronic 60 updatedb > /dev/null # update slocate every minute Note: use 'jobs' to list background tasks and fg/bg to take control of them.

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"

Execute a sudo command remotely, without displaying the password
The ssh command alone will execute the sudo command remotely, but the password will be visible in the terminal as you type it. The two stty commands disable the terminal from echoing the password back to you, which makes the remote sudo act as it does locally.

Generat a Random MAC address
Original author unknown (I believe off of a wifi hacking forum). Used in conjuction with ifconfig and cron.. can be handy (especially spoofing AP's)

Find biggest 10 files in current and subdirectories and sort by file size


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.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

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: