Restore AST 'pty' pseudoterminal command (re: reboot)

This enables the tests/pty.sh regression tests for the interactive
shell to work. I've managed to restore these without restoring
nmake (which would cause unresolved build failures). It involved
hand-editing the Mamfile originally generated by nmake.

src/cmd/builtin/Makefile:
- Restored. Even though nmake is not installed, apparently mamake
  still needs the Makefile for the 'install' target to work. This
  will probably need editing if nmake is ever restored.

src/cmd/builtin/Mamfile:
- Restored and edited by hand to remove the commands to build all
  the utilities except pty, as well as all test targets (pty has no
  test). Most of this was systematically deleting blocks delimited
  by 'make FOO' and 'done FOO generated' until the build stopped
  failing -- a task made so much easier by the build now failing
  gracefully on error (see d0dfb37c). To see the diff, do:
	git diff cc1f2bf8 src/cmd/builtin/Mamfile

src/cmd/builtin/RELEASE:
- Restored for completeness' sake with all non-pty entries removed.

src/cmd/builtin/features/pty,
src/cmd/builtin/pty.c:
- Restored.

src/cmd/builtin/Makefile

@@ -0,0 +1,90 @@
+/*
+ * standalone versions of -lcmd builtins
+ */
+
+:PACKAGE: ast cmd:space
+
+LICENSE = since=1992,author=gsf+dgk
+
+:ALL:
+
+:: cmdlib.h builtin.c
+
+CMD_BUILTIN ==
+CMD_DYNAMIC ==
+CMD_STANDALONE ==
+
+LINKS = cp: ln mv cksum: md5sum sum
+NOBIN = getconf
+
+CAT = $(STDCAT|"cat")
+CMP = $(STDCMP|"cmp") 2>/dev/null
+CP = $(STDCP|"cp")
+LN = $(STDLN|"ln")
+RM = $(STDRM|"rm")
+
+BUILTINS :COMMAND: cmdlist.h
+	$(SED) -e '/^CMDLIST(.*)$/!d' -e 's/CMDLIST(\(.*\))/\1/' $(NOBIN:C,.*,-e '/^&$/d',) $(LINKS:N!=*[:]:C,.*,-e '/^&$/d',) $(*)
+
+.INIT : .builtin
+
+.builtin : .MAKE .VIRTUAL .FORCE
+	local T I
+	if T = "$(NOBIN:D=$(BINDIR):B:S:T=F)"
+		{ $(RM) $(RMFLAGS) $(T) }
+	end
+	:ALL: $(BUILTINS)
+	T = -lcmd
+	if "$(PACKAGE_OPTIONS:N=optimize-space)" && "$(T:T=F)" == "-lcmd"
+		T := $(BUILTINS:O=1)
+		$(T) :: CMD_BUILTIN=1 CMD_DYNAMIC=1 builtin.c -lcmd -ldll
+		for I $(BUILTINS:O>1)
+			$(I) :LINK: $(T)
+		end
+		for I $(LINKS)
+			if I != "*:"
+				$(I) :LINK: $(T)
+			end
+		end
+	else
+		$(BINDIR) :INSTALLDIR: $(BUILTINS)
+		$(BUILTINS) : .COMMAND $(&$("%.c":T=SM%)) CMD_BUILTIN=b_$$(<:B) builtin.c $(*$("%.c":T=SM%))
+			$(CAT) $(*:N=*builtin.c) > $(<).c
+			$(RM) $(RMFLAGS) $(<)
+			$(@$("%.c":T=SM%):/.*builtin.c$/$(<).c/)
+			$(RM) $(RMFLAGS) $(<).c
+		for I $(LINKS)
+			if I == "*:"
+				T := $(I:/.$//)
+			else
+				$(I) :LINK: $(T)
+			end
+		end
+	end
+
+":BUILTIN:" : .MAKE .OPERATOR
+	local T P
+	for T $(>)
+		if T == "*=*"
+			$(P).o : $(T)
+		elif T == "[-+]l*"
+			$(P) : $(T)
+		else
+			eval
+			$(T) :: CMD_STANDALONE=b_$(T) $(T).c
+			end
+			P := $(T)
+		end
+	end
+
+:BUILTIN: dlls LICENSE=since=2002,author=gsf -ldll look mime \
+		pty LICENSE=since=2001,author=gsf+dgk -lutil \
+		nl LICENSE=since=2003,author=dgk asa od pr \
+		strings tr uudecode -luu uuencode -luu what who
+
+dontcare -lutil
+
+:: PROMO.mm RELEASE
+
+:TEST: asa cat chmod chown cksum cmp cp cut date expr fmt head join ln \
+	look mkdir mkfifo mktemp mv nl od paste rm tail tr uniq uuencode wc

src/cmd/builtin/Mamfile

@@ -0,0 +1,95 @@
+info mam static 00000 1994-07-17 make (AT&T Research) 5.7 2012-06-20
+setv INSTALLROOT ../../..
+setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
+setv PACKAGE_ast_LIB ${INSTALLROOT}/lib
+setv PACKAGE_cmd ${INSTALLROOT}
+setv PACKAGE_cmd_INCLUDE ${PACKAGE_cmd}/include
+setv PACKAGE_cmd_LIB ${PACKAGE_cmd}/lib
+setv PACKAGEROOT ../../../../..
+setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
+setv ARFLAGS rc
+setv AS as
+setv ASFLAGS
+setv CC cc
+setv mam_cc_FLAGS
+setv CCFLAGS ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv CCLDFLAGS ${-strip-symbols?1?${mam_cc_LD_STRIP}??}
+setv COTEMP $$
+setv CPIO cpio
+setv CPIOFLAGS
+setv CPP "${CC} -E"
+setv F77 f77
+setv HOSTCC ${CC}
+setv IGNORE
+setv LD ld
+setv LDFLAGS
+setv LEX lex
+setv LEXFLAGS
+setv LPR lpr
+setv LPRFLAGS
+setv M4FLAGS
+setv NMAKE nmake
+setv NMAKEFLAGS
+setv PR pr
+setv PRFLAGS
+setv SHELL /bin/sh
+setv SILENT
+setv TAR tar
+setv YACC yacc
+setv YACCFLAGS -d
+make ${PACKAGEROOT}/lib/package/ast.lic
+done ${PACKAGEROOT}/lib/package/ast.lic
+make .INIT
+make ${PACKAGE_ast_INCLUDE}/cmdlist.h
+make ${PACKAGE_ast_INCLUDE}/prototyped.h implicit
+done ${PACKAGE_ast_INCLUDE}/prototyped.h dontcare
+done ${PACKAGE_ast_INCLUDE}/cmdlist.h
+exec - sed -e '/^CMDLIST(.*)$/!d' -e 's/CMDLIST(\(.*\))/\1/' -e '/^getconf$/d' -e '/^ln$/d' -e '/^mv$/d' -e '/^md5sum$/d' -e '/^sum$/d' ${PACKAGE_ast_INCLUDE}/cmdlist.h
+bind -lcmd
+done .INIT dontcare virtual
+make install
+make pty
+make pty.o
+make pty.c
+make FEATURE/pty implicit
+meta FEATURE/pty features/%>FEATURE/% features/pty pty
+make features/pty
+done features/pty
+exec - iffe -v -c '${CC} ${mam_cc_FLAGS} ${CCFLAGS}   ${LDFLAGS} ' ref ${mam_cc_L+-L${INSTALLROOT}/lib} -I${PACKAGE_ast_INCLUDE} -I${INSTALLROOT}/include ${mam_libast} ${mam_libcmd} : run features/pty
+done FEATURE/pty generated
+make ${PACKAGE_ast_INCLUDE}/ast_time.h implicit
+done ${PACKAGE_ast_INCLUDE}/ast_time.h
+prev ${PACKAGE_ast_INCLUDE}/vmalloc.h implicit
+prev ${PACKAGE_ast_INCLUDE}/regex.h implicit
+make ${PACKAGE_ast_INCLUDE}/proc.h implicit
+prev ${PACKAGE_ast_INCLUDE}/ast.h implicit
+prev ${PACKAGE_ast_INCLUDE}/prototyped.h implicit
+done ${PACKAGE_ast_INCLUDE}/proc.h
+prev ${PACKAGE_ast_INCLUDE}/error.h implicit
+prev ${PACKAGE_ast_INCLUDE}/cmd.h implicit
+done pty.c
+meta pty.o %.c>%.o pty.c pty
+prev pty.c
+setv CMD_STANDALONE -DCMD_STANDALONE="b_pty"
+setv LICENSE -DLICENSE="since=2001,author=gsf+dgk"
+exec - ${CC} ${mam_cc_FLAGS} ${CCFLAGS} -I. -I${PACKAGE_ast_INCLUDE} -DERROR_CATALOG=\""builtin"\" -D_PACKAGE_ast -DCMD_STANDALONE=b_pty -DUSAGE_LICENSE=\""[-author?Glenn Fowler <gsf@research.att.com>][-author?David Korn <dgk@research.att.com>][-copyright?Copyright (c) 2001-2012 AT&T Intellectual Property][-license?http://www.eclipse.org/org/documents/epl-v10.html][--catalog?builtin]"\" -c pty.c
+done pty.o generated
+bind -lutil dontcare
+setv CMD_STANDALONE -DCMD_STANDALONE="b_pty"
+exec - ${CC} ${CCLDFLAGS} ${mam_cc_FLAGS} ${CCFLAGS} ${LDFLAGS} ${mam_cc_L+-L.} ${mam_cc_L+-L${INSTALLROOT}/lib} -o pty pty.o ${mam_libutil} ${mam_libast} ${mam_libcmd}
+done pty generated
+make ${INSTALLROOT}/bin
+exec - if silent test ! -d ${INSTALLROOT}/bin
+exec - then mkdir -p ${INSTALLROOT}/bin
+exec - fi
+done ${INSTALLROOT}/bin generated
+make ${INSTALLROOT}/bin/pty
+prev pty
+exec - test '' = 'pty' || ${STDCMP} 2>/dev/null -s pty ${INSTALLROOT}/bin/pty || { ${STDMV} ${INSTALLROOT}/bin/pty ${INSTALLROOT}/bin/pty.old 2>/dev/null || true; ${STDCP} pty ${INSTALLROOT}/bin/pty ;}
+done ${INSTALLROOT}/bin/pty generated
+make ${INSTALLROOT}/bin
+exec - if silent test ! -d ${INSTALLROOT}/bin
+exec - then mkdir -p ${INSTALLROOT}/bin
+exec - fi
+done ${INSTALLROOT}/bin virtual
+done install virtual

src/cmd/builtin/RELEASE

@@ -0,0 +1,10 @@
+12-02-28 pty.c: change --verbose[=level] to --debug=level
+12-01-26 pty.c: fix --man docs
+10-06-21 pty.c: add 4 sec timeout for initial handshake -- fix me!!
+10-04-12 pty: fix sfpoll() result read/write bug
+10-04-01 pty: add --tty='stty-settings'
+10-03-19 pty: add --dialogue
+10-03-15 pty: fix select() fd management
+09-03-31 features/pty,Makefile: add pty.h and -lutil refs for linux -- great, another util library
+09-01-30 pty.c: add <ast_time.h> (for fd_set!! on mvs.390)
+06-07-20 pty.c: add

src/cmd/builtin/features/pty

@@ -0,0 +1,60 @@
+set	prototyped
+
+header	sys/types.h
+header	pty.h
+header	libutil.h
+header	sys/pty.h
+header	sys/ptyio.h
+header	sys/vty.h
+header	sys/ioctl.h
+header	stropts.h
+
+lib	openpty,_getpty,ptsname -lutil
+lib	grantpt,unlockpt,posix_openpt stdlib.h
+
+tst - output{
+	#include	<sys/types.h>
+	#include	<sys/stat.h>
+	#if _lib_ptsname && _npt_ptsname
+	_BEGIN_EXTERNS_
+	#if _STD_
+		extern char*	ptsname(int);
+	#else
+		extern char*	ptsname();
+	#endif
+	#endif
+	_END_EXTERNS_
+	int main()
+	{
+		int		i;
+		struct stat	statb;
+		static char*	pty[] = { "/dev/ptyp0000", "/dev/ptym/ptyp0", "/dev/ptyp0" };
+	#if _lib_ptsname
+		int		fd;
+		static char*	ptc[] = { "/dev/ptmx", "/dev/ptc", "/dev/ptmx_bsd" };
+
+		for (i = 0; i < sizeof(ptc) / sizeof(ptc[0]); i++)
+			if((fd = open(ptc[i], 2))>=0)
+			{
+				if (ptsname(fd))
+				{
+					printf("#define _pty_clone\t\"%s\"\n", ptc[i]);
+					close(fd);
+					break;
+				}
+				close(fd);
+			}
+	#endif
+		for (i = 0;; i++)
+			if(i >= (sizeof(pty) / sizeof(pty[0]) - 1) || stat(pty[i], &statb)>=0)
+			{
+				printf("#define _pty_first\t\"%s\"\n", pty[i]);
+				break;
+			}
+		return 0;
+	}
+}end  
+
+extern	_getpty		char*		(int*, int, mode_t, int)
+extern	openpty		int		(int*, int*, char*, struct termios*, struct winsize*)
+extern	ptsname		char*		(int)