char[] to long[] converter

/* This program converts a char[] to a long[].
 * Because it uses sizeof (long) and memcpy(), it should be portable between big/little-endian
 * and 16/32/64-bit systems.
 *
 * Mostly pointless, just for fun, used for constructing obfuscated message-printing programs.
 */

#include <stdio.h>
#include <string.h>

#define ENCODE_BUFSZ 1000
#define FMT_STR(evil_, norm_) (evil_mode ? evil_ : norm_)

static int evil_mode = 0;

void
write_output(unsigned long *output, size_t len)
{
    if(len)
        printf(FMT_STR("%lu", "0x%lx"), output[0]);

    for(int i = sizeof (long), j = 1; i < len; j++, i += sizeof (long))
        printf(FMT_STR(", %lu", ", 0x%lx"), output[j]);
}

void
encode(char *msg)
{
    unsigned long output[ENCODE_BUFSZ] = {0};

    memcpy(output, msg, strlen(msg));

    printf("unsigned long msg[] = { ");
    write_output(output, strlen(msg));
    printf(" }; // %s\n", msg);
}

int
usage(void)
{
    fputs( "usage: ./a.out [options] \"string\" [string2 string3 ...]\n"
           "options:\n"
           "  -e  activate evil mode, which prints output in base 10.\n\n"
           "example: ./a.out \"Hello World\" \"Goodbye World\" I\\\'m On Separate Lines\n", stderr);
    return 1;
}

void
parse_arg(char *arg)
{
    if(!strcmp(arg, "-e"))
        evil_mode = 1;

    else
        encode(arg);
}

int
parse_args(char **args)
{
    if(!*args)
        return usage();

    while(*args)
        parse_arg(*(args++));

    return 0;
}

int
main(int argc, char **argv)
{
    return parse_args(argv + 1);
}