Use estrtoul() in dd(1)

Allow specifications in hex and octal as well.

Makefile

@@ -10,6 +10,7 @@ LIB = \
 	util/ealloc.o         \
 	util/eprintf.o        \
 	util/estrtol.o        \
+	util/estrtoul.o       \
 	util/explicit_bzero.o \
 	util/proc.o           \
 	util/putword.o        \

dd.c

@@ -237,15 +237,15 @@ main(int argc, char *argv[])
 		else if (sscanf(argv[i], "of=%1023c", buf) == 1)
 			config.out = strdup(buf);
 		else if (sscanf(argv[i], "skip=%1023c", buf) == 1)
-			config.skip = strtoul(buf, NULL, 10);
+			config.skip = estrtoul(buf, 0);
 		else if (sscanf(argv[i], "seek=%1023c", buf) == 1)
-			config.seek = strtoul(buf, NULL, 10);
+			config.seek = estrtoul(buf, 0);
 		else if (sscanf(argv[i], "count=%1023c", buf) == 1)
-			config.count = strtoul(buf, NULL, 10);
+			config.count = estrtoul(buf, 0);
 		else if (strcmp(argv[i], "direct") == 0)
 			config.direct = 1;
 		else if (sscanf(argv[i], "bs=%1023c", buf) == 1)
-			config.bs = strtoul(buf, NULL, 10);
+			config.bs = estrtoul(buf, 0);
 		else if (strcmp(argv[i], "bs") == 0)
 			config.bs = 0;
 		else if (strcmp(argv[i], "quiet") == 0)

util.h

@@ -27,6 +27,9 @@ char *estrdup(const char *);
 /* estrtol.c */
 long estrtol(const char *, int);
 
+/* estrtoul.c */
+unsigned long estrtoul(const char *, int);
+
 /* explicit_bzero.c */
 #undef explicit_bzero
 void explicit_bzero(void *, size_t);

util/estrtoul.c

@@ -0,0 +1,26 @@
+/* See LICENSE file for copyright and license details. */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../util.h"
+
+unsigned long
+estrtoul(const char *s, int base)
+{
+	char *end;
+	unsigned long n;
+
+	errno = 0;
+	n = strtoul(s, &end, base);
+	if(*end != '\0') {
+		if(base == 0)
+			eprintf("%s: not an integer\n", s);
+		else
+			eprintf("%s: not a base %d integer\n", s, base);
+	}
+	if(errno != 0)
+		eprintf("%s:", s);
+
+	return n;
+}