stty cbreak -echo; KEY=$(dd bs=1 count=1 2>/dev/null); stty -cbreak echo

Read a keypress without echoing it

This shell snippet reads a single keypress from stdin and stores it in the $KEY variable. You do NOT have to press the enter key! The key is NOT echoed to stdout! This is useful for implementing simple text menus in scripts and similar things.

5
By: inof
2009-06-09 13:15:49

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  • This command will play back each keystroke in a session log recorded using the script command. You'll need to replace the ^[ ^G and ^M characters with CTRL-[, CTRL-G and CTRL-M. To do this you need to press CTRL-V CTRL-[ or CTRL-V CTRL-G or CTRL-V CTRL-M. You can adjust the playback typing speed by modifying the sleep. If you're not bothered about seeing each keypress then you could just use: cat session.log Show Sample Output


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  • 5 helpful aliases for using the which utility, specifically for the GNU which (2.16 tested) that is included in coreutils. Which is run first for a command. Same as type builtin minus verbosity alias which='{ command alias; command declare -f; } | command which --read-functions --read-alias' Which (a)lias alias whicha='command alias | command which --read-alias' Which (f)unction alias whichf='command declare -f | command which --read-functions' Which e(x)ecutable file in PATH alias whichx='command which' Which (all) alias, function, builtin, and files in PATH alias whichall='{ command alias; command declare -f; } | command which --read-functions --read-alias -a' # From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    2
    alias whichall='{ command alias; command declare -f; } | command which --read-functions --read-alias -a'
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What Others Think

This is very interesting, and could be helpful for some of my scripts :)
leviself · 467 weeks and 1 day ago
The read command actually does this for you. -s for silent (i.e. no echo), and -n1 to tell it that you only want the one character read. read -s -n1 KEY
Hobbletoe · 467 weeks ago
wow i came to favourite inof's, but hobbletoe's seems even awesomer! definitely have some scripts that will be improved by this!
cephi · 466 weeks and 4 days ago
Hobbletoe: "read -s" is non-standard and not portable. I guess it works only with bash (I don't have a bash here, so I can't test, but none of my other bourne shell implementations support it).
inof · 466 weeks and 1 day ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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