#include #include union { short s; char c[sizeof(short)]; } un; int main(void) { char *os; un.s = 0x0102; /* what kind of system are we using? */ if (os=getenv("OS")) printf("OS:\t\t\t%s\n", os); if (os=getenv("OSTYPE")) printf("OSTYPE:\t\t\t%s\n", os); if (os=getenv("MACHTYPE")) printf("MACHTYPE:\t\t%s\n", os); if (os=getenv("VENDOR")) printf("VENDOR:\t\t\t%s\n", os); if (os=getenv("HOSTTYPE")) printf("HOSTTYPE:\t\t%s\n", os); printf("\n"); if (sizeof(short) == 2) { if (un.c[0] == 1 && un.c[1] == 2) printf("This system uses big-endian byte order\n"); else if (un.c[0] == 2 && un.c[1] == 1) printf("This system uses little-endian byte order\n"); else printf("Unknown.\n"); } else printf("sizeof(short) = %d\n", sizeof(short)); return(0); }