Reclaim standard in from the tty for a script that is in a pipeline

[ ! -t 0 ] && [ -t 1 ] && exec 0<&1
Tests to see if stdin (0) is NOT a terminal. Tests to see if stdout (1) IS a terminal. Copies stdout (opened for write) to stdin (open for read).
Sample Output
# THIS IS A BASIC DEMO SCRIPT
$ cat ttytest.sh 
#!/bin/bash

while read -t 0.05 ; do
        echo -n . 
done ; echo
read -p "Hello? " R1
echo "${R1:-No reply}"
[ ! -t 0 ] && [ -t 1 ] && exec 0<&1
read -p "Hello?? " R2
echo "${R2:-No reply}"


# RUN IT WITHOUT PIPING
$ bash ttytest.sh 

Hello? hi
hi
Hello?? hi again
hi again


# RUN IT WITH PIPING
$ date | bash ttytest.sh 
.
No reply
Hello?? Hi 
Hi

0
2017-04-12 00:10:27

1 Alternatives + Submit Alt

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