cannot read input while calling from function

Question

below you will find a simple code. i am calling function input if the read input is Y however read command in input function never executes.

#!/bin/bash
input() {
    read -p "Press any key to continue..." # read input (this part never executed) 
}

mg() # prompt user for y=true, n=false
{
    [ $FORCE ] && echo>&2 "$* (forced)" && return
    while read<&2 -p "$* (Y/N)? [Y] " YN
    do
        [ -z "$YN" -o "$YN" = Y ] && return
        [ "$YN" = N ] && return 1
    done
    err "failed to read from YN   $*"    
}


if mg "Enter Input?"       
then in="yes" | input # call function input if mg return Y
else in="no"
fi

Try executing with "bash -x <your_script>" to see what's going on. — ewan.chalmers
– ewan.chalmers, Commented Jul 24, 2013 at 12:22

chepner · Accepted Answer · 2013-07-24 12:29:03Z

3

The call to input is getting its standard output from the parameter assignment. As soon as the assignment completes, its (nonexistant) standard output is closed, which read interprets as EOF which causes the read to return.

Use a semi-colon instead.

if mg "Enter Input?"
then in="yes"; input
else in="no"
fi

(Removing the pipeline also allows in to be assigned in the current shell, not in the pipeline-induced subshell.)

answered Jul 24, 2013 at 12:29

chepner

538k77 gold badges595 silver badges747 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

ahilsend · Accepted Answer · 2013-07-24 12:28:54Z

0

Your line

then in="yes" | input

is the issue. You don't want to pipe the assignment of in into input. Separate the commands with a semicolon or a newline:

then in="yes"; input

answered Jul 24, 2013 at 12:28

ahilsend

9316 silver badges15 bronze badges

Collectives™ on Stack Overflow

cannot read input while calling from function

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related