4

I need to run a program in the background. I know that using '&' after a command runs the command in the background.

In the following script:

#!/bin/bash
echo amt of time delay nsec
read nano
echo amt of time delay in sec
read sec
echo no.of times
read i
while [ $i -ne 0 ]
do
./nanosleep $sec $nano
./schello
i=$[i-1]
done

I have a few data that I get from the user. Is there a way I can run the program in background and while calling the program can I also specify the data required (like nano, sec,i) as arguments or through some other way?

7

If your script is called, let say test.sh, then you can for example:

  • pipe your input:

    echo -e "1\n2\n3\n" | test.sh &
    

    where 1, 2, and 3 are the values for $nano, $sec and, respectively $i.

  • take the input from a file:

    test.sh < arguments.txt &
    
  • use a here string:

    test.sh <<< $'1\n2\n3\n' &
    
  • The 1st one was more than enough though had to use ./test.sh – Bas Mar 27 '14 at 3:51
1

Another possibility is to pass those variables as arguments to your script. In your script, instead of

read nano
read sec
read i

...you may use:

nano=$1
sec=$2
i=$3

The variables $1, $2, $3, etc. correspond to the first, second, third, etc. arguments on the command line. Thus you can call your script as:

test.sh foo bar buz &

Inside the script, $1 will contain foo, $2 will contain bar, $3 will contain buz, etc.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.