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I can ask the user to press Enter by using read, and have him wait by calling sleep. But I can’t think of a way of doing both at the same time. I would like the user to be given the choice:
Press Ctrl+C to Cancel, Enter to continue or just wait 10 seconds
How can I do that?
921
bash [filename] runs the commands saved in a file. $@ refers to all of a shell script's command-line arguments. $1 , $2 , etc., refer to the first command-line argument, the second command-line argument, etc. Place variables in quotes if the values might have spaces in them.
timeout is a command-line utility that runs a specified command and terminates it if it is still running after a given period of time.
Bash read Built-in The first word is assigned to the first name, the second one to the second name, and so on. The general syntax of the read built-in takes the following form: read [options] [name...] To illustrate how the command works, open your terminal, type read var1 var2 , and hit “Enter”.
In bash, read has a -t option where you can specify a timeout. From the manpage:
read [-ers] [-u fd] [-t timeout] [-a aname] [-p prompt] [-n nchars] [-d delim] [name ...]
-t timeout:cause read to time out and return failure if a complete line of input is not read within timeout seconds. This option has no effect if read is not reading input from the terminal or a pipe.
Transcript below (without hitting ENTER):
$ date ; read -t 10 -p "Hit ENTER or wait ten seconds" ; echo ; date Tue Feb 28 22:29:15 WAST 2012 Hit ENTER or wait ten seconds Tue Feb 28 22:29:25 WAST 2012 Another, hitting ENTER after a couple of seconds:
$ date ; read -t 10 -p "Hit ENTER or wait ten seconds" ; date Tue Feb 28 22:30:17 WAST 2012 Hit ENTER or wait ten seconds Tue Feb 28 22:30:19 WAST 2012 And another, hitting CTRL-C:
$ date ; read -t 10 -p "Hit ENTER or wait ten seconds" ; echo ; date Tue Feb 28 22:30:29 WAST 2012 Hit ENTER or wait ten seconds If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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