Commands by derwiki (2)

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

Happy Days
This never gets old

create random numbers within range for conjob usage
if you need to install cron jobs in a given time range.

Convert JSON to YAML

shuffle lines via bash
Using perl in a one-liner is a bit overkill to randomly sort some input. `sort` from coreutils should be enough.

Generate a Google maps URL for GPS location data from digital photo
This command uses the "exiftool" command which is available here: http://www.sno.phy.queensu.ca/~phil/exiftool/ NB, there should be a degree symbol right after the first "%d" NOT a question mark. For some unknown reason, commandlinefu is not able to handle degree symbol correctly ("?")?

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" }

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"

chmod - change file permissions of a file to be similar of another

Download SSL server certificate with opsnessl
Useful when we need to create new certificate for site when current one is near expiry. This downloaded cert can be used to provide organisational data directly to new cert. using below command. e.g. openssl x509 -x509toreq -in /tmp/example.com.cert -out example.com.csr -signkey example.com-key.pem

run complex remote shell cmds over ssh, without escaping quotes
It executes commands as arguments to ssh, avoiding problematic shell expansions, without the need of writing the commands in question to a temporary file, just reading them from STDIN.

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: