if ! [ -t 1 ]; then
exec 3>&1
exec 1>$(tty)
fi
doing this
1>&-
will close &3 as well.
note doing this
exec 1>/dev/fd/1
is the same as doing this
exec 1>&1
Am 28.05.2012 04:32, schrieb Bill Gradwohl:
I'm trying to detect when a scripts stdout is redirected, and then create another fd to accept the redirection but put fd 1 back to the terminal. I need fd 1 & fd 2 pointing at the terminal and fd 3 pointing at the file. All of them open at the same time.
Setting up fd 3 is OK. but I can't get fd 1 connected back to the terminal as though redirection never happened.
Assume the script below is called redir.
#!/bin/bash
if ! [ -t 1 ]; then
exec 3>&1
echo "went to 3">&3
1>&-
# exec 1>/proc/self/fd/1
# exec 1>/dev/stdout
# exec 1>/dev/fd/1
echo "went to 1"
fi
As is produces:
address@hidden ycc# ./redir >xxx; cat xxx
went to 3
went to 1
I closed fd1 and yet the naked echo ends up in the file. I don't understand how that works after a close.
The 3 comments are my attempts to reconnect fd back to the console / terminal.
Activating any one of them causes the output that went to fd3 to disappear, probably do to fd 1 stepping on the file anew.
How does one connect a fd to the console, NOT USING fd 1 or fd 2 targets?
Thank You
--
Bill Gradwohl
--
