> POSIX is a specification. Not a program. The thing that actually runs your script is bash, dash, ash, ksh, yash, or one of a dozen others. They each implement

> POSIX is a specification. Not a program. The thing that actually runs your script is bash, dash, ash, ksh, yash, or one of a dozen others. They each implement POSIX with their own gaps, extensions, and historical accidents. Blaming POSIX, because a program does not implement it, is childish.