Programming Perl, 4th Edition

chdir

chdir EXPR
chdir

This function changes the current process’s working directory to EXPR, if possible. If EXPR is omitted, $ENV{HOME} is used if set, and $ENV{LOGDIR} otherwise; these are usually the process’s home directory. The function returns true on success, false otherwise.

chdir("$prefix/lib") || die "Can't cd to $prefix/lib: $!";

See also the Cwd module, which lets you keep track of your current directory automatically.

On systems that support fchdir(2), you may pass a filehandle or directory handle as EXPR. On systems that don’t support fchdir(2), passing handles raises a runtime exception.