the special grep:s could not be built since we lack /sys/mman.h

mkmk -o grep -S -B -a -I../include -I/sys/include/ape/heirloom -D_POSIX_SOURCE -D_SUSV2_SOURCE -D_BSD_EXTENSION -x svid3.c -x grep.c -x fgrep.c -x egrep.y -x egrep.c > mkfile

mkmk -o fgrep -S -B -a -I../include -I/sys/include/ape/heirloom -D_POSIX_SOURCE -D_SUSV2_SOURCE -D_BSD_EXTENSION -x ggrep.c -x sus -x egrep.y -x egrep.c > mkfile.fgrep

mkmk -o egrep -S -B -a -I../include -I/sys/include/ape/heirloom -D_POSIX_SOURCE -D_SUSV2_SOURCE -D_BSD_EXTENSION -x ggrep.c -x egrep.y -x sus > mkfile.egrep