unsetenv — unset an environment variable mask then chain
unsetenv
{var
} {next-prog
}
C-shells have a built-in unsetenv command that does not chain. See the manual for each individual shell for its built-in command.
unsetenv is a chain-loading utility that unsets the environment variable var
and then chain loads to next-prog
with the execvp(3) function.
next-prog
may contain its own command line options, which unsetenv will ignore.
Unsetting a variable is not the same as setting it to an empty value. For that, see setenv(1).
If var
contains an equals
character, counter-intuitive things will happen to the environment.