How to print a string with embedded nulls so that “(null)” is substituted for '\0'

Question

I have a string I composed using memcpy() that (when expanded) looks like this:

char* str = \"AAAA\\x00\\x00\\x00...\\x11\\x11\\x11\\x11\\x00\\x00...\";
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Answer 1

From C++ Reference on puts() (emphasis mine):

Writes the C string pointed by str to stdout and appends a newline character ('\n'). The function begins copying from the address specified (str) until it reaches the terminating null character ('\0'). This final null-character is not copied to stdout.

To process data such as you have, you'll need to know the length. From there, you can simply loop across the characters:

/* ugly example */
char* str = "AAAA\x00\x00\x00...\x11\x11\x11\x11\x00\x00...";
int len = ...; /* get the len somehow or know ahead of time */
for(int i = 0; i < len; ++i) {
  if('\0' == str[i]) {
    printf(" (null) ");
  } else {
    printf(" %c ", str[i]);
  }
}