I'm trying to use a bash script for a psych experiment that involves listening to sound files and responding. If I have something like the code below, how can I make sure that a key press is assigned to RESPONSE only after the second echo statement?
Also, maybe this is the same question, but how can I make sure that if there are accidentally two or more key presses, that the extra presses are ignored instead of getting assigned to RESPONSE on the next iteration(s)?
It is pretty easy in C with fseek(stdin, 0, SEEK_END);, but I don't know of any portable (or even any way without explicit keyboard actions initiated by the user at the terminal) way to do that with shell code.
Have you considered writing this in C?
Note also that asking a question (e.g. Ready?) and expecting users not to respond seems like you're asking for unwanted input.
Since you specify using bash shell we can flush the input buffer using:
so your script would look like this:
Hi Chubler_XL,
That might work with some versions of bash, but it won't work with 3.2.57 (which comes with the most recent release of macOS Mojave) since the read built-in in that version doesn't have a -N option. The loop you suggest above silently throws away the diagnostic saying there is no -N option and gives no indication that whatever was intended to be done by the while loop didn't do anything. The following read then reads the next available character no matter when it was typed.
Since darwin_866 has told us neither what OS is being used nor which version of bash is being used, we don't have any way to know if what you suggested might work in his/her environment.
I am trying to allow a user to enter in text and then store that text in a variable $gene to run in an awk command in which those values are used to run some calculations. I am getting syntax errors however, when I try. Thank you :).
The awk runs great if it is a pre-defined file that is used,... (7 Replies)
Why does removing "rhgb quiet" from the kernel boot parameters control whether or not the commands I enter are displayed in single user mode ?
For instance, if I do not remove "rhgb quiet", when I am in single user mode, whatever command I type will not be displayed on the screen.
The... (0 Replies)
$Input_filename=$ARGV;
if (!-d $Input_filename && ! -e $Input_filename)
{
print "USAGE: Please enter '$ABCD/def/dsed.txt' as an arguement \n";
exit;
}
1. Input Is suppose to be something like "$ABCD/def/dsed.txt".
if the input is wrong the script should throw an ERROR message.... (2 Replies)
i have a script which takes input from user, if user gives either Y/y then it should continue, else it should quit by displaying user cancelled.
#!/bin/sh
echo " Enter your choice to continue y/Y OR n/N to quit "
read A
if
then
echo " user requested to continue "
##some commands... (7 Replies)
Hi,
echo "Enter file name of input file list along with absolute path : "
read inputFileList
if
then
for string in `cat inputFileList`
do
echo $string
done
else
echo " file does not exist"
fi
From the above code, if the user enters a invalid file... (1 Reply)
If I want all user input to start with " : " if not display error
or what I asking is how to do if statement that control a first letter of string that we want to start with. and not worry about the rest
Thank (1 Reply)
I'm trying to set up a script that takes user input and validates that the user input was entered correctly.
So far I have this:
while :
do
echo "Please enter your name."
read NAME
if
then
echo "You have not entered a name."
echo... (13 Replies)
Hello all,
How can i have a user input that reads like this:
echo -n "Please enter a & b:" 10 20
read a
read b
echo $a
echo $b
10
20
right now i have divided it into two echos, like
echo -n "a: "
echo -n "b: " (1 Reply)
I am trying to create a shell (ksh) which has two "read" commands, one which reads a line from a file and another which is inside a loop that reads user input from a keyboard. However, the "read" command inside the loop uses the input from the file and it does not get the user input from keyboard.... (3 Replies)