C - little code, file descriptor, segmentation fault - c

Question

I have write this code but i have a problem
first i have a function that create a file descriptor (fd)
int fd;//global
static int init_fd(int fd) {
remove("file descriptor.txt");//if yet present
fd = open("file descriptor.txt", O_WRONLY | O_CREAT, 0666);
if (fd == -1) {
printf("Error in opening the file descriptor!\n");
exit(0);
}
return fd;
}
the second function is a handler function
static int handler(struct connection *conn, enum event ev) {
...
int i;
for (i = 0; i < array_size; i++) {
if (!strncmp(conn->uri, uri_array[i], strlen(uri_array[i]))) {
func_array[i](conn->request_method, conn->uri, NULL, init_fd(fd));
close(fd);
fd = open("file descriptor.txt", O_RDONLY);
ret = read(fd, &buf, BUFSIZ);
if (ret == -1) {
printf("Error in reading!\n");
exit(0);
}
...
}
with fun_array is a pointer to function
httpCallback_t func_array[MAXARRAY];
and the function is
void http_serve1(const char *method, const char *path, const httpOptions_t *options, int fd) {
const char *string = "All is ok1!";
int ret_value;
// send header: 200 OK
ret_value = sendHeaders(fd, TIMEOUT_SEC, NETHTTP_HTTP_HEADER_200, NETHTTP_Content_Type_text_html_utf8, NETHTTP_CRLF, NULL);
// close the file descriptor
close(fd);
}
and the function sendHeaders is
size_t sendHeaders(int fd, int seconds, const char* header1, ...) {
va_list args;
va_start(args, header1);
size_t totalSize = 0;
const char* hdr = header1;
while (hdr != NULL) {
size_t result = sendHeaders(fd, seconds, hdr, NULL); // segmentation fault
if (result < 0) {
return result;
}
totalSize += result;
hdr = va_arg(args, const char*);
va_end(args);
return totalSize;
}
if (size == SIZE) {
setErrorCode(ERROR);
return ERROR;
}
size_t sizewrite = 1024;
tmp[size] = strdup(hdr);
write(fd, tmp, sizewrite);
setErrorCode(SUCCESS);
return SUCCESS;
}
my problem is that my code create a file descriptor, but it doesn't write inside, and during the run i have problem with segmentation fault. anyone have a suggest?