Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

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:

Hide

News

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

Look up a unicode character by name

Terminal - Look up a unicode character by name
grep -i "$*" /usr/lib/perl5/Unicode/CharName.pm | while read a b; do /usr/bin/printf "\u$a\tU+%s\t%s\n" "$b"; done
2011-01-04 11:30:16
User: ioggstream
Functions: grep read
1
Look up a unicode character by name

No need for further filedes or substitution for splitting. Simply use read a b

Alternatives

There are 2 alternatives - vote for the best!

Terminal - Alternatives
egrep -i "^[0-9a-f]{4,} .*$*" $(locate CharName.pm) | while read h d; do /usr/bin/printf "\U$(printf "%08x" 0x$h)\tU+%s\t%s\n" $h "$d"; done
2010-12-31 16:47:59
User: hackerb9
Functions: egrep locate read
12

[Update! Thanks to a tip from ioggstream, I've fixed both of the bugs mentioned below.]

You, yes, 𝙔𝙊𝙐, can be the terror of the Internet! Why use normal, boring bullet points in your text, when you could use a ROTATED HEAVY BLACK HEART BULLET (❥)!? (Which would also be an awesome band name, by the way).



This script makes it easy to find unusual characters from the command line. You can then cut and paste them or, if you're using a GTK application, type Control+Shift+U followed by the code point number (e.g., 2765) and then a SPACE.



USAGE: Put this script in a file (I called mine "ugrep") and make it executable. Run it from the command line like so,



ugrep heart



The output will look like this,



☙ U+2619 REVERSED ROTATED FLORAL HEART BULLET

♡ U+2661 WHITE HEART SUIT

♥ U+2665 BLACK HEART SUIT

❣ U+2763 HEAVY HEART EXCLAMATION MARK ORNAMENT

❤ U+2764 HEAVY BLACK HEART

❥ U+2765 ROTATED HEAVY BLACK HEART BULLET

❦ U+2766 FLORAL HEART

❧ U+2767 ROTATED FLORAL HEART BULLET

⺖ U+2E96 CJK RADICAL HEART ONE

⺗ U+2E97 CJK RADICAL HEART TWO

⼼ U+2F3C KANGXI RADICAL HEART



You can, of course, use regular expressions. For example, if you are looking for the "pi" symbol, you could do this:



ugrep '\bpi\b'



REQUIREMENTS: Although this is written in Bash, it assumes you have Perl installed because it greps through the Perl Unicode character name module (/usr/lib/perl5/Unicode/CharName.pm). Note that it would not have made more sense to write this in Perl, since the CharName.pm module doesn't actually include a subroutine for looking up a character based on the description. (Weird.)



BUGS: In order to fit this script in the commandlinefu limits, a couple bugs were added. ① Astral characters beyond the BMP (basic multilingual plane) are not displayed correctly, but see below. ② Perl code from the perl module being grepped is sometimes extraneously matched.



MISFEATURES: Bash's printf cannot, given a Unicode codepoint, print the resulting character to the terminal. GNU's coreutils printf (usually "/usr/bin/printf") can do so, but it is brokenly pedantic about how many hexadecimal digits follow the escape sequence and will actually die with an error if you give the wrong number. This is especially annoying since Unicode code points are usually variable length with implied leading zeros. The CharNames.pm file represents BMP characters as 4 hexits, but astral characters as 5. In the actual version of this script that I use, I've kludged around this misfeature by zero-padding to 8 hexits like so,



/usr/bin/printf "\U$(printf "%08x" 0x$hex)"



TIP 1: The author recommends "xsel" for command line cut-and-paste. For example,



ugrep biohazard | xsel



TIP 2: In Emacs, instead of running this command in a subshell, you can type Unicode code points directly by pressing Control-Q first, but you'll likely want to change the default input from octal to hexadecimal. (setq read-quoted-char-radix 16).



TIP 3: Of course, if you're using X, and you want to type one of the more common unusual characters, it's easiest of all to do it with your Compose (aka Multi) key. For example, hitting [Compose] <3 types ♥.

Know a better way?

If you can do better, submit your command here.

What others think

Thanks for the tip, ioggstream, that saved me just enough characters. I'd forgotten about using read to split words. Now the original version uses your suggestion, plus adds the two bug fixes I'd left out before.

Comment by hackerb9 199 weeks and 1 day ago

@hackerb9: glad to know, thx ;)

Comment by ioggstream 198 weeks and 2 days ago

Your point of view

You must be signed in to comment.

Related sites and podcasts