new utilities.

the .C files compile but are renamed to avoid building automatically.

src/cmd/touch.c

@@ -0,0 +1,62 @@
+#include <u.h>
+#include <libc.h>
+
+int touch(int, char *);
+ulong now;
+
+void
+usage(void)
+{
+	fprint(2, "usage: touch [-c] [-t time] files\n");
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int nocreate = 0;
+	int status = 0;
+
+	now = time(0);
+	ARGBEGIN{
+	case 't':
+		now = strtoul(EARGF(usage()), 0, 0);
+		break;
+	case 'c':
+		nocreate = 1;
+		break;
+	default:	
+		usage();
+	}ARGEND
+
+	if(!*argv)
+		usage();
+	while(*argv)
+		status += touch(nocreate, *argv++);
+	if(status)
+		exits("touch");
+	exits(0);
+}
+
+int
+touch(int nocreate, char *name)
+{
+	Dir stbuff;
+	int fd;
+
+	nulldir(&stbuff);
+	stbuff.mtime = now;
+	if(dirwstat(name, &stbuff) >= 0)
+		return 0;
+	if(nocreate){
+		fprint(2, "touch: %s: cannot wstat: %r\n", name);
+		return 1;
+	}
+	if ((fd = create(name, OREAD, 0666)) < 0) {
+		fprint(2, "touch: %s: cannot create: %r\n", name);
+		return 1;
+	}
+	dirfwstat(fd, &stbuff);
+	close(fd);
+	return 0;
+}