An exit code (also called exit status or return code) is a number returned by a command or script when it finishes.
Meaning:
0→ Success (command ran without errors)- Non-zero (
1,2,127, etc.) → Failure (different numbers mean different types of errors)
You can check the last command’s exit code using:
echo $?
Define output exit code:
#!/bin/bash
cp file.txt /some/path
if [ $? -ne 0 ]; then
echo "Copy failed!"
exit 1
fi