Prints IP string out to console ok, But wont fwrite() them

OS = Windows XP, Compiler = Microsoft Visual C++
I want to save out the computers various IPs to a log. Here is my Function that works fine up untill saving the actual IPs to the log.

Code:

void IPaddress()
{
	FILE *file;
	char *ip;
	long datasize; // used writing to log
	WORD wVersionRequested;
	 WSADATA wsaData;
	 char name[255] ={0}; 
	
	 PHOSTENT hostinfo;
	 wVersionRequested = MAKEWORD( 1, 1 );	 

	 if ( WSAStartup( wVersionRequested, &wsaData ) == 0 )
		 if( gethostname ( name, sizeof(name)) == 0)
		 {
		    datasize = sizeof (name);			// used to write computer name to file
		    printf("Computername: %s\n", name);
		    file=fopen(InfoFile,"a+");
		    fwrite(name , 1 , datasize , file); // write computer name to file Works Fine
		    fclose(file);						// close, could leave open for following code.

			   if((hostinfo = gethostbyname(name)) != NULL)
			   {
					int nCount = 0;
					while(hostinfo->h_addr_list[nCount])
						{
//next I use inet_ntoa which converts the specified Internet host address to a STRING in the Internet standard dot notation.

							 ip = inet_ntoa(*(struct in_addr *)hostinfo->h_addr_list[nCount]);
							 printf("IP #%d: %s\n", ++nCount, ip);	  // This works fine Prints IPs list to console OK	 
							 file=fopen(InfoFile,"a+");		 // Reopen : InfoFile is Defined in Seperate Header
							 fwrite(ip , 1 , sizeof(ip) , file);	  // Write IPs to file ?? Why cant I save this IP string?
																		// Is it actually a string? 							 
							 fclose(file);		 		
						}
				 }
		  }
			
}//end

It gives the following output to the console which is Good.

Code:

Output On console
Computername : themaster
IP #1:10.0.0.7
IP #2:192.168.91.1
IP #3:192.168.40.1

This is what is acutally saved to log
themaster

So bacically only the computername is actually writen to log, Why dosnt it write IPs part. I am not fully comprhending something. This is my understnding of it .

inet_ntoa() converts the specified Internet host address to a string pointed to by "ip". Then I just fwrite that string to file?

Try writing to the file with fprintf().

Instread of using sizeof use strlen to get the length of the string to output. Sizeof(IP) is like saying sizeof(char *)

Originally Posted by sand_man

Try writing to the file with fprintf().

Ahh thanks thats what I was looking for fprintf() does the trick nicely. I looked at it for ages and fprintf() never even entered my mind. lol Thanks very much

Heres the section that needed to be changed.

Code:

ip = inet_ntoa(*(struct in_addr *)hostinfo->h_addr_list[nCount]);
fprintf (file, "\nIP:  %-7.16s",ip);	//%-7.16s = min of 7 characters  maximum  16 characters EX: 1.1.1.1 or 255.255.255.255					
printf("IP #%d: %s\n", nCount++, ip);

fyi:

you could use fprintf exclusively here instead of fwrite and printf additionally.. -for what you are doing here anyway:

Code:

//print to file
fprintf(file, "\nIP:  %-7.16s",ip);

//print to the default standard output pipe
fprintf(stdout, "IP #%d: %s\n", nCount++, ip);\

//also stderr is another output available..
//and stdin for reading