Bash Script Sourcing Pattern with Isolated Exit Codes

Bash Script Sourcing Pattern with Isolated Exit Codes

Problem: Need to access functions defined in .bashrc (not exported with export -f) while allowing scripts to use exit without terminating the calling shell.

Solution: Source the script in a subshell: (source script.sh)

Implementation

Parent Script (scratch1.sh)

#!/bin/bash

foo123() {
  echo "foo1 that is defined in scratch 1"
}

main() {
  (source /path/to/scratch2.sh) || {
    throw "Scratch 2 failed"
  }
  echo.green "end in scratch 1"
}

main "${@}" || exit 1

Child Script (scratch2.sh)

#!/bin/bash

main() {
  foo123  # Can call parent's functions
  echo.red "exiting in scratch2"
  exit 1  # Only exits the subshell
}

main "${@}" || exit 1

How It Works

• () creates a subshell that inherits parent functions
• exit in child only terminates the subshell
• || catches the exit code for error handling

Benefits

• Access to non-exported functions
• Safe exit handling
• Clean error propagation
• Normal script semantics

Use Cases

• Quick scripts using shell convenience functions
• Development/prototyping
• Legacy integration where functions aren't exported