write binary datas in a pipe

[cantubas]

i want to write binary data in a gz file.

i can create file.gz with the popen but i can't write my datas.

printf does't like binary datas like null char


thanks

 

[ArkM]

Yes, of course, printf don't like binary data because of it dedicated to print formatted (i.e text) data (but it can write in binary mode too).
Use ANSI/ISO Standard library function fwrite():

size_t fwrite( const void *buffer, size_t size, size_t count, FILE *stream );
...
char data[100];
... // Write 1st 25 bytes to FILE* stream:
numwritten = fwrite(data, sizeof(char), 25, stream );
...

Don't forget to open a stream on a file (pipe) in binary mode.