# OS only allows DETECT, UNIX, OSX, FREEBSD, OPENBSD, MORPHOS, BEOS, HAIKU, SUNOS, CYGWIN, MINGW, OS2, DOS, WINCE, and PSP
if [ -z "`echo $os | egrep '^(DETECT|UNIX|OSX|FREEBSD|OPENBSD|NETBSD|HPUX|MORPHOS|BEOS|HAIKU|SUNOS|CYGWIN|MINGW|OS2|DOS|WINCE|PSP)$'`" ]; then
# OS only allows DETECT, UNIX, OSX, FREEBSD, DRAGONFLY, OPENBSD, NETBSD, MORPHOS, BEOS, HAIKU, SUNOS, CYGWIN, MINGW, OS2, DOS, WINCE, and PSP
if [ -z "`echo $os | egrep '^(DETECT|UNIX|OSX|FREEBSD|DRAGONFLY|OPENBSD|NETBSD|HPUX|MORPHOS|BEOS|HAIKU|SUNOS|CYGWIN|MINGW|OS2|DOS|WINCE|PSP)$'`" ]; then
log 1 "configure: error: invalid option --os=$os"
log 1 " Available options are: --os=[DETECT|UNIX|OSX|FREEBSD|OPENBSD|NETBSD|HPUX|MORPHOS|BEOS|HAIKU|SUNOS|CYGWIN|MINGW|OS2|DOS|WINCE|PSP]"
log 1 " Available options are: --os=[DETECT|UNIX|OSX|FREEBSD|DRAGONFLY|OPENBSD|NETBSD|HPUX|MORPHOS|BEOS|HAIKU|SUNOS|CYGWIN|MINGW|OS2|DOS|WINCE|PSP]"