Bash read/write file descriptors — seek to start of file

Question

I tried to use the read/write file descriptor in bash so that I could delete the file that the file descriptor referred to afterward, as such:

F=$(mktemp)
ex         


        

Answer 1

#!/bin/bash
F=$(mktemp tmp.XXXXXX)
exec 3<> $F
rm $F

echo "Hello world" >&3
cat /dev/fd/3

As suggested in other answer, cat will rewind the file descriptor for you before reading from it since it thinks it's just a regular file.