Unknown option: "-1" Unix manual page for true. (host=minya system=Darwin) 
TRUE(1)                   BSD General Commands Manual                  TRUE(1)

NAME
     true -- Return true value.

SYNOPSIS
     true

DESCRIPTION
     The true utility always returns with exit code zero.

SEE ALSO
     csh(1), sh(1), false(1)

STANDARDS
     The true utility conforms to IEEE Std 1003.2-1992 (``POSIX.2'').

BSD                              June 27, 1991                             BSD