chdir
Changes the process’s current working directory.
Changes the working directory to the specified path. If called
with no argument or an empty string, changes to the directory
specified by the HOME environment variable (or / if HOME
is not set).
Returns 1 on success, undef on failure.
Synopsis
chdir("/tmp") or die "Cannot chdir: $!";
chdir($dir);
chdir(); # changes to $HOME
chdir(""); # also changes to $HOME