Category "variables"

Posix shell: distinguish between empty and not existing variable

In pure /bin/sh how can I distinguish between an empty variable, an unset variable and a not existing (not defined) variable. Here are the case: # Case 1: not

Posix shell: distinguish between empty and not existing variable

In pure /bin/sh how can I distinguish between an empty variable, an unset variable and a not existing (not defined) variable. Here are the case: # Case 1: not

Posix shell: distinguish between empty and not existing variable

In pure /bin/sh how can I distinguish between an empty variable, an unset variable and a not existing (not defined) variable. Here are the case: # Case 1: not