Dump9660 (and mk9660). Until we either do something

intelligent with symlinks or put in a switch for things
like dump9660, this is of rather limited utility under Unix.

src/cmd/9660/unix.c

@@ -0,0 +1,84 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <libsec.h>
+#include <disk.h>
+#include <ctype.h>
+
+#include "iso9660.h"
+
+#include <grp.h>
+#include <pwd.h>
+
+typedef struct Xarg Xarg;
+struct Xarg {
+	void (*enm)(char*,char*,XDir*,void*);
+	void (*warn)(char*,void*);
+	void *arg;
+};
+
+static long numericuid(char *user);
+static long numericgid(char *gp);
+
+void
+dirtoxdir(XDir *xd, Dir *d)
+{
+	//	char buf[NAMELEN+1];
+	memset(xd, 0, sizeof *xd);
+
+	xd->name = atom(d->name);
+	xd->uid = atom(d->uid);
+	xd->gid = atom(d->gid);
+	xd->uidno = numericuid(d->uid);
+	xd->gidno = numericgid(d->gid);
+	xd->mode = d->mode;
+	xd->atime = d->atime;
+	xd->mtime = d->mtime;
+	xd->ctime = 0;
+	xd->length = d->length;
+	if(xd->mode & CHLINK) {
+		xd->mode |= 0777;
+		//xd->symlink = atom(d->symlink);
+		xd->symlink = atom("symlink");		// XXX: rsc
+	}
+};
+
+void
+fdtruncate(int fd, ulong size)
+{
+	ftruncate(fd, size);
+
+	return;
+}
+
+static long
+numericuid(char *user)
+{
+	struct passwd *pass;
+	static int warned = 0;
+
+	if (! (pass = getpwnam(user))) {
+		if (!warned)
+			fprint(2, "Warning: getpwnam(3) failed for \"%s\"\n", user);
+		warned = 1;
+		return 0;
+	}
+
+	return pass->pw_uid;
+}
+
+static long
+numericgid(char *gp)
+{
+	struct group *gr;
+	static int warned = 0;
+
+	if (! (gr = getgrnam(gp))) {
+		if (!warned)
+			fprint(2, "Warning: getgrnam(3) failed for \"%s\"\n", gp);
+		warned = 1;
+		return 0;
+	}
+
+	return gr->gr_gid;
+}