Get dc(1) to build

.gitignore

@@ -0,0 +1 @@
+dc/dc

LICENSE.nortti

@@ -0,0 +1,19 @@
+    Copyright (c) 2021 nortti
+
+    This software is provided 'as-is', without any express or implied
+    warranty. In no event will the authors be held liable for any damages
+    arising from the use of this software.
+
+    Permission is granted to anyone to use this software for any purpose,
+    including commercial applications, and to alter it and redistribute
+    it freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+       claim that you wrote the original software. If you use this software
+       in a product, an acknowledgment in the product documentation would be
+       appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+       misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source distribution.

Makefile

@@ -0,0 +1,36 @@
+DESTDIR ?=
+PREFIX ?= /usr/local
+EXEC_PREFIX ?= $(PREFIX)
+BINDIR ?= $(EXEC_PREFIX)/bin
+LIBEXECDIR ?= $(EXEC_PREFIX)/libexec
+DATAROOTDIR ?= $(PREFIX)/share
+MANDIR ?= $(DATAROOTDIR)/man
+
+BINS := dc/dc
+MAN1S := dc/dc.1
+
+.SUFFIXES:
+.SUFFIXES: .c .o
+
+.PHONY: all install uninstall clean distclean
+
+all: $(BINS)
+
+dc/dc: dc/dc.c dc/dc.h
+	$(CC) -o $@ $(CFLAGS) $(CPPFLAGS) $< $(LDFLAGS)
+
+.c.o:
+	$(CC) -c $(CFLAGS) $(CPPFLAGS) -o $@ $<
+
+install: $(BINS) $(MAN1S)
+	install -D -m 755 -t '$(DESTDIR)$(BINDIR)' $(BINS)
+	install -D -m 644 -t '$(DESTDIR)$(MANDIR)/man1' $(MAN1S)
+
+uninstall:
+	cd $(DESTDIR)$(BINDIR) && rm $(BINS)
+	cd $(DESTDIR)$(MANDIR)/man1 && rm $(MAN1S)
+
+clean:
+	rm -f $(BINS)
+
+distclean: clean

dc/COPYING

@@ -3,3 +3,5 @@ dc.c is derived from 4.4BSD. See LICENSE.bsd
 
 Additionally, the files have been modified by Gunnar Ritter. See
 LICENSE.gritter
+
+dc.c has been modified by nortti. See LICENSE.nortti

dc/dc.c

@@ -43,13 +43,14 @@
  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /*	Sccsid @(#)dc.c	1.21 (gritter) 12/25/06>	*/
+/* Modified by nortti, 2021 */
 
+#define _XOPEN_SOURCE 500
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <signal.h>
-#include "sigset.h"
 #include <stdlib.h>
 #include <inttypes.h>
 #include <limits.h>
@@ -1669,7 +1670,7 @@ command(void){
 		}
 		*sl = 0;
 		if((pid = fork()) == 0){
-			execl(SHELL,"sh","-c",line,NULL);
+			execl("/bin/sh","sh","-c",line,NULL);
 			exit(0100);
 		}
 		savint = sigset(SIGINT, SIG_IGN);