a - shell functions return codes function return codes are used to indicate the success or failure of a function's execution. also known as exit statuses a return code of 0 indicates successful execution while any other value indicates an error or failure. return 0 → returns 0 for successful execution return 1 → return 1 for non succesful execution check_success $? → $? captures the return code
b - shell function exit command and local variables exit command terminates a script execution based on some condition You can also return code using exit commad exit 0 → terminates execution with return code 0 exit 1 → terminates execution with return code 1 local variables are used to define variables within a specific scope or context inside a function. These variables are not accessible outside the function They do not affect or interfere with global variables of the same name. local result=$1 → declares a local variable with the name result
c - shell functions error handling Error handling is an essential aspect of writing robust shell scripts strategies for implementing effective error handling in functions within your shell scripts: using return codes using set -e → automatically fails on error using trap → Trap errors and handle them manually Using set -u → automatically fails on undefined variables set -e → exits immediately if a command exits with a non-zero status. set -u → fails on an undefined variable. trap 'echo "An error... → traps errors and handle them manually.