read inside a while loop

UNIX for Beginners Q & A UNIX for Dummies Questions & Answers
1

Hi all,

In a while loop, like below...

while read line
do
read choice

case $choice in
1)
echo "xxx"
esac

done < file
why I can't run the read choice????

2

instead of simple read use

read response < /dev/tty

Because as the default stream in while has been associated with the file, read will not read from terminal.

Note: Redirecting terminal will slowen ur script a bit as it is heavy on resources.

3

Hi Dta,

  I too have same problem...i am getting "line" value into "choice" and not getting the input from terminal.

 I am looking for a soultion to use "read" twice in a while loop.

Thanks...

4

Rather than wrestling with the shell to do this - make it easy on yourself and use Perl - for example, to only print the line if the user enters a 1....

#!/usr/bin/perl

open( FOOFILE, "< foofile" );
while( <FOOFILE> ) {
  print( "Enter a number: " );
  chomp( $input = <STDIN> );
  if ( $input == 1 ) {
    print( "You entered a 1 and the line is $_" );
  } else {
    print( "Ooops - not a 1\n" );
  }
}
close( FOOFILE );

Cheers
ZB