first draft

byteorder.c

@@ -0,0 +1,85 @@
+#if 0
+#
+# Compile with:
+#	$sh byteorder.c
+#
+cc byteorder.c -o byteorder || exit 1
+echo successfully compiled
+exit
+#endif /* 0 */
+
+/* 
+ * $smu-mark$ 
+ * $name: byteorder.c$ 
+ * $author: Salvatore Sanfilippo <antirez@invece.org>$ 
+ * $copyright: Copyright (C) 1999 by Salvatore Sanfilippo$ 
+ * $license: This software is under GPL version 2 of license$ 
+ * $date: Fri Nov  5 11:55:47 MET 1999$ 
+ * $rev: 9$ 
+ */ 
+
+/*
+ * 0.1 first version
+ * 0.2 add Strchr, so it's possibile remove string.h
+ * 0.3 more portable thx to Pancrazio De Mauro 'TrantIT'!!!
+ * 0.4 better debug output
+ */
+
+#include <stdio.h>
+
+char *Strchr(char *s, char c)
+{
+	while(*s)
+		if (*s++ == c)
+			return s;
+
+	return (char*) 0;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned int test = 1;
+	unsigned char *x;
+	int macro = 0, debug = 0, help = 0, j;
+
+	for (j = 1; j < argc; j++) {
+		if (Strchr(argv[j], 'm')) macro = 1;
+		if (Strchr(argv[j], 'd')) debug = 1;
+		if (Strchr(argv[j], 'h')) help = 1;
+	}
+
+	if (help) {
+		printf(	"-m	macro output\n"
+			"-d	debug\n"
+			"-h	help\n");
+		return 0;
+	}
+		
+	x = (unsigned char*) &test;
+
+	if (*x == 0x00) {
+		if (macro)
+			printf("__BIG_ENDIAN_BITFIELD\n");
+		else
+			printf("big endian\n");
+	}
+	else if (*x == 0x01) {
+		if (macro)
+			printf("__LITTLE_ENDIAN_BITFIELD\n");
+		else
+			printf("little endian\n");
+	} else {
+		printf("\nWARNING!!! byteorder exception\n\n");
+		debug = 1;
+	}
+
+	if (debug) {
+		printf("sizeof(unsigned int) = %d\n", sizeof(unsigned int));
+		printf("unsigned int test = 1;\n");
+		printf("in memory as: ");
+		for (j = 0; j < sizeof(unsigned int); j++)
+			printf("%02x ", x[j]);
+		printf("\n");
+	}
+	return 0;
+}