print hex dump of memory

hexdump.c

void hexDump (char *desc, void *addr, int len) {
    int i;
    unsigned char buff[17];       // stores the ASCII data
    unsigned char *pc = addr;     // cast to make the code cleaner.

    // Output description if given.

    if (desc != NULL)
        printf ("%s:\n", desc);

    // Process every byte in the data.

    for (i = 0; i < len; i++) {
        // Multiple of 16 means new line (with line offset).

        if ((i % 16) == 0) {
            // Just don't print ASCII for the zeroth line.

            if (i != 0)
                printf ("  %s\n", buff);

            // Output the offset.

            printf ("  %p ", addr + i);
        }

        // Now the hex code for the specific character.

        printf (" %02x", pc[i]);

        // And store a printable ASCII character for later.

        if ((pc[i] < 0x20) || (pc[i] > 0x7e))
            buff[i % 16] = '.';
        else
            buff[i % 16] = pc[i];
        buff[(i % 16) + 1] = '\0';
    }

    // Pad out last line if not exactly 16 characters.

    while ((i % 16) != 0) {
        printf ("   ");
        i++;
    }

    // And print the final ASCII bit.

    printf ("  %s\n", buff);
}