File opening in CURL - c

Question

I am writing a c program using libcurl. I am connecting to a server running on localhost and then saving this retrieved data from server in a file. When I use the filename such as "file.txt", then I can write and read my file. But when I try to change the filename and append it with current data and time, I get an error "Failed Writing received data to disk/application".
Following is my code:
` int main(int argc, char *argv[])
{
float freq;
CURL *curl;
CURLcode res;
FILE *fp, *file_r;
char *buffer;
buffer = malloc (100000);
char url[1024], name[20];
char *filename;
filename = (char *) malloc (100);
if (filename == NULL)
{
printf("Error in memory allocation");
}`
/* Store the data retireved from webpage in a file and name the file with current date and time */
time_t now;
time (&now);
struct tm *t = localtime (&now);
strftime (name, 20, "%d %m %Y %H:%M:%S", t);
// printf ("%s\n", name);
filename[0] ='\0'; // Ensure the memory is an emtpy string;
strcat (filename, "file_new_");
strcat (filename, name);
strcat (filename, ".txt");
printf ("%s\n", filename);
printf("enter your input frequency value\n");
scanf("%f", &freq);
sprintf(url, "http://127.0.0.1:8080/?action=update_frequency&update_frequency=%f",freq);
/* In windows, this will init the winsock stuff */
curl_global_init(CURL_GLOBAL_ALL);
/* get a curl handle */
curl = curl_easy_init();
if(curl)
{
curl_easy_setopt(curl, CURLOPT_URL, "http://127.0.0.1:8080");
/* Now specify the username & pwd */
curl_easy_setopt(curl, CURLOPT_USERPWD, "admin:12345");
/* Specify the web request */
curl_easy_setopt(curl, CURLOPT_URL, url);
/* Storing the received data in a file */
fp = fopen (filename, "w+");
curl_easy_setopt (curl, CURLOPT_WRITEDATA, fp);
/* Perform the request, res will get the return code */
res = curl_easy_perform(curl);
/* Check for errors */
if (res != CURLE_OK)
{
fprintf(stderr, "curl_easy_perform() failed: %s\n",curl_easy_strerror(res));
}
fclose (fp);
/* To read the return msg from server after performing a request */
file_r= fopen (filename, "r");
fseek (file_r, SEEK_SET, 0);
while (fgets (buffer, 100000, file_r)!=NULL)
{
;
}
printf( "%s\n", buffer);
fclose (file_r);
}
/* always cleanup */
curl_easy_cleanup(curl);
curl_global_cleanup();
return 0;
}
If anyone has any idea, would be of great help.
Thanks much

Answer 1

You can't use the character : in a filename on Windows, so that's why it fails to save. Change the separator to something else.