Thanks for the explanation. I ran a different, more complex application with a deliberate seg fault added again using my method above and now see the following as the output:
sh: line 1: 26902 Segmentation fault my_complex_executable_that_s
+egfaults > /dev/null
return value is 35584
exit_value = 139
signal_num = 0
dumped_core = 0
In the above case,
0x80 | signal_num = 0x80 | 0x0B = 0x8B = 139, which matches the listed
exit_value. 35584 is just the exit value shifted up 8 bits, which is consistent with the definition of $?.
What does the 26902 value indicate? Is that the 16-bit status int set by wait(2) from running my_complex_executable_that_segfaults that can be parsed by perl to assemble the fields of the $? variable, and can also be accessed directly in C/C++ using the macros WTERMSIG, WEXITSTATUS, etc. (source: https://linux.die.net/man/2/wait)?