[SOLVED] -e option not inherited by bash scripts?

Issue

I thought any script launched from a bash environnement that has -e option set would inherit this -e option. It seems it is not the case Below, a bash subshell is launched and -e option is set , echo_set_options is a small script that just echoes its $- value

>( set -e; echo $- ; echo_set_options )
ehimBHs
$-=hB

with echo_set_options just echoing $- :

#!/usr/bin/bash
echo $-

I don't really understand why let -e option be inherited by subshells and not by scripts

Another question : where is it possible to find description of all flags that make $- value ?

I know that e stands for -e option, B means brace expansion , i for interactive, but what about s for instance ? I haven't found the description of $- value

Thanks for your help !

Solution

A subshell is a copy of the existing process created by fork()ing that process with no execve() syscall. Consequently, it gets all your state -- all your local variables (not just environment variables) and all your configuration flags.

A script run as a child process is a whole new process, created by a fork() followed by an execve(). That execve() completely replaces the memory image of the process with a new piece of software; environment variables survive, as do open file descriptors, but not any of the process-local memory state.

Answered By - Charles Duffy

Answer Checked By - David Goodson (WPSolving Volunteer)