I've this code in which I receive a server response, check if it's a successful one, and if it is - create the file under the requested path and then write the response body to the file:

I'm testing it with the following URL:

CodePudding user response：

write(fd, buf   header_size, tot_read - header_size) != (buf_size - header_size)

From man 3p write:

   Upon successful completion, these functions shall return the number of bytes actually  written  to  the  file  associated  with
   fildes.  This number shall never be greater than nbyte.  Otherwise, -1 shall be returned and errno set to indicate the error.

Only when write() == -1 then errno is set, otherwise it is irrelevant - leftover from some other operation. The number returned by write() can be lower than the requested number of bytes.

You have to write a small loop where you loop over the bytes to be written. When by it, consider handling errno == EAGAIN.