There is a way to get the output of a running process. But it should be considered a hack:
Let's say the PID of the process is 22499:
Let's say the PID of the process is 22499:
~$ touch log ~$ gdb -p 22499 (gdb) p close(1) # This closes the stdout of the running process (gdb) p open("/home/.../log", 1) # This will open the log-file with O_WRITE (gdb) c