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/util.c

@@ -0,0 +1,98 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <libsec.h>
+#include <ctype.h>
+
+#include "iso9660.h"
+
+typedef struct Stringtab	Stringtab;
+struct Stringtab {
+	Stringtab *link;
+	char *str;
+};
+
+static Stringtab *stab[1024];
+
+static uint
+hash(char *s)
+{
+	uint h;
+	uchar *p;
+
+	h = 0;
+	for(p=(uchar*)s; *p; p++)
+		h = h*37 + *p;
+	return h;
+}
+
+static char*
+estrdup(char *s)
+{
+	if((s = strdup(s)) == nil)
+		sysfatal("strdup(%.10s): out of memory", s);
+	return s;
+}
+
+char*
+atom(char *str)
+{
+	uint h;
+	Stringtab *tab;
+	
+	h = hash(str) % nelem(stab);
+	for(tab=stab[h]; tab; tab=tab->link)
+		if(strcmp(str, tab->str) == 0)
+			return tab->str;
+
+	tab = emalloc(sizeof *tab);
+	tab->str = estrdup(str);
+	tab->link = stab[h];
+	stab[h] = tab;
+	return tab->str;
+}
+
+void*
+emalloc(ulong n)
+{
+	void *p;
+
+	if((p = malloc(n)) == nil)
+		sysfatal("malloc(%lud): out of memory", n);
+	memset(p, 0, n);
+	return p;
+}
+
+void*
+erealloc(void *v, ulong n)
+{
+	if((v = realloc(v, n)) == nil)
+		sysfatal("realloc(%p, %lud): out of memory", v, n);
+	return v;
+}
+
+char*
+struprcpy(char *p, char *s)
+{
+	char *op;
+
+	op = p;
+	for(; *s; s++)
+		*p++ = toupper(*s);
+	*p = '\0';
+
+	return op;
+}
+
+int
+chat(char *fmt, ...)
+{
+	va_list arg;
+
+	if(!chatty)
+		return 0;
+	va_start(arg, fmt);
+	vfprint(2, fmt, arg);
+	va_end(arg);
+	return 1;
+}