bash: ending statements

I was reviewing a bash script that I use recently and noticed the esac keyword. I hadn’t noticed it before, so I started looking into it a bit more and found that it signifies the end of a case statement.

This “reverse word” technique to mark the end of a code block apparently has its roots in the ALGOL68 language’s expressions

• if is closed with fi
• case is closed with esac
• do is od, but in bash it has been replaced with done, likely to avoid conflicting with octal dump. Similarly done is used for for, while, and until loops.