Why 0 is true but false is 1 in the shell?

Question

false; echo $?

The above will output 1, which is contradictory with all other programming languages I know.

Any reason in this

Answer 1

Bash is a programming (scripting) language, but it's also a shell and a user-interface. If 0 was error, then the program could only present one kind of error.

However in Bash, any nonzero value is an error, and we may use any number from 1-255 to represent an error. This means we can have many different kinds of errors. 1 is a general error, 126 means that a file cannot be executed, 127 means 'command not found', etc. Here's a list of Bash Exit Codes With Special Meanings showing some of the most common exit codes.

There are also many kinds of success (exit status is 0). However, a success will allow you to proceed to the next step—you can like print results to a screen, or execute a command, etc.