How to exit if a command failed?

Question

I am a noob in shell-scripting. I want to print a message and exit my script if a command fails. I\'ve tried:

my_command && (echo \'my_command failed         


        

Answer 1

Provided my_command is canonically designed, ie returns 0 when succeeds, then && is exactly the opposite of what you want. You want ||.

Also note that ( does not seem right to me in bash, but I cannot try from where I am. Tell me.

my_command || {
    echo 'my_command failed' ;
    exit 1; 
}