Commands by themiurgo (3)

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

Annotate tail -f with timestamps
Uses the command ts in order to add a timestamp on each line. This command is provided in the moreutils package on Debian, and you may need libtime-duration-perl to be able to format the date.

View all file operator expressions for any file, test, stat
Applies each file operator using the built-in test. $ testt /home/askapache/.sq /home/askapache/.sq -a True - file exists. -d True - file is a directory. -e True - file exists. -r True - file is readable by you. -s True - file exists and is not empty. -w True - the file is writable by you. -x True - the file is executable by you. -O True - the file is effectively owned by you. -G True - the file is effectively owned by your group. -N True - the file has been modified since it was last read. Full Function: testt () { local dp; until [ -z "${1:-}" ]; do dp="$1"; [[ ! -a "$1" ]] && dp="$PWD/$dp"; command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp"; [[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null; for f in a b c d e f g h L k p r s S t u w x O G N; do test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-\([a-zA-Z]\{1\}\) F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g'; done; shift; done }

python smtp server
This command will start a simple SMTP server listening on port 1025 of localhost. This server simply prints to standard output all email headers and the email body.

Check SATA link speed.
Check SATA controller type. 6.0 Gbps - SATA III 3.0 Gbps - SATA II 1.5 Gbps - SATA I

Show complete URL in netstat output
This takes all of the tab spaces, and uses column to put them into the appropriately sized table.

Resample a WAV file with sox
Change the sample rate with sox, the swiss army knife of sound processing.

List Listen Port by numbers
Show TCP Listen ports sorted by number (bugs: IPV6 addresses not supported)

Use tcpdump to monitor all DNS queries and responses

Intercept, monitor and manipulate a TCP connection.
Forwards localhost:1234 to machine:port, running all data through your chain of piped commands. The above command logs inbound and outbound traffic to two files. Tip: replace tee with sed to manipulate the data in real time (use "sed -e 's/400 Bad Request/200 OK/'" to tweak a web server's responses ;-) Limitless possibilities.

View all date formats, Quick Reference Help Alias
If you have used bash for any scripting, you've used the date command alot. It's perfect for using as a way to create filename's dynamically within aliases,functions, and commands like below.. This is actually an update to my first alias, since a few commenters (below) had good observations on what was wrong with my first command. # creating a date-based ssh-key for askapache.github.com $ ssh-keygen -f ~/.ssh/`date +git-$USER@$HOSTNAME-%m-%d-%g` -C 'webmaster@askapache.com' $ # /home/gpl/.ssh/git-gplnet@askapache.github.com-04-22-10 # create a tar+gzip backup of the current directory $ tar -czf $(date +$HOME/.backups/%m-%d-%g-%R-`sed -u '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.

» 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: