how to insert a \0 to a binary file in C

I have to insert a bunch of chars to a binary file.

In order to do that I use fwrite. After that, I would like to put a \0.

I am not sure how to do it.

const unsigned char *my_word; /*my_word has no \0 at the end*/

fwrite(my_word, my_word_length_in_bytes, 1, my_file);

Can you please help开发者_运维知识库?

Thanks.

You can use the following:

fputc(0, my_file);

You need to have your buffer my_word alocated with +1, then

my_word[my_word_length_in_bytes]=0;
fwrite(my_word, my_word_length_in_bytes+1, 1, my_file);

`fputc('\0', my_file);` will do it for you

An old trick is to use an empty null-terminated string

fwrite("", 1, 1, my_file);

You can either concatenate a '\0' character at the end of word before you actually write it into your file (best solution imho) or do a second fwrite with a 0x00 byte (which is ASCII code for '\0').