#if 0 # # Compile with: # $sh byteorder.c # cc byteorder.c -o byteorder || exit 1 echo successfully compiled exit #endif /* 0 */ /* Coypright (C) 1999-2003 Salvatore Sanfilippo */ /* * 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 */ /* $Id: byteorder.c,v 1.2 2003/09/01 00:22:06 antirez Exp $ */ #include 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; }