Enable, disable and print builtin shell commands.
The return value is 0 unless a name is not a shell builtin or there is an error loading a new builtin from a shared object.
For example, to use the test binary found via the PATH instead of the shell builtin version, run enable -n test.
Disabling a builtin allows a disk command which has the same name as a shell builtin to be executed without specifying a full pathname, even though the shell normally searches for builtins before disk commands.
If no name arguments are given, or if the -p option is supplied, a list of shell builtins is printed.
- With no other option arguments, the list consists of all enabled shell builtins.
- If -n is supplied, only disabled builtins are printed.
- If -a is supplied, the list printed includes all builtins, with an indication of whether or not each is enabled.
- If -s is supplied, the output is restricted to the POSIX special builtins.