How to attach a process in gdb
Try one of these:
gdb -p 12271
gdb /path/to/exe 12271
gdb /path/to/exe
(gdb) attach 12271
The first argument should be the path to the executable program. So
gdb progname 12271
With a running instance of myExecutableName
having a PID 15073
:
hitting Tab twice after $ gdb myExecu
in the command line, will automagically autocompletes to:
$ gdb myExecutableName 15073
and will attach gdb to this process. That's nice!