How to pass in a null character in a command line argument in C?

Question

I would still like to know how to pass in a null character as a command line argument, maybe so that a single string can be passed in as an argument in the form:

"to\0be\0or\0not\0to\0be\0"

And then parse it. However the program would treat this string as:

"to\\0be\\0or\\0not\\0to\\0be\\0"

How can I work around this? Is there any way?

Answer 1

C strings are null-terminated, so passing strings containing NUL characters is not possible in C. :-P

Now, if you just wanted a way to convert \0 (in the user input, i.e., "\\0" as a C string) into actual NUL characters, that's another matter. In that case, your program just needs a parser to treat \0 as separators.

Answer 2

You cannot.

The C program receives arguments as zero-terminated strings. Such a string cannot contain a null character, by definition.

If you want to pass a null character, then you must somewhat encode it with some syntax, and your C program must then decode it by interpreting that syntax.