Thread: little program confusion

I'm having a bit of trouble letting the user supply the port number as an argument. I have a feeling it's a simple fix.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define BUFFER 1024
#define TESTPORT 9999

int i;
void display_usage(void);
char *TARGETIP,the_buffer[BUFFER],return_data[BUFFER];

int main( int argc, char *argv[] ) {

         if( argc < 2 )
         {
         display_usage();
         exit(1);
         }
        
         //printf("You entered %s\n", argv[2]);
         TARGETIP = argv[1]; // TARGETIP had to be a pointer
         //TESTPORT = argv[2];  

         //fill the buffer up with 1024 A's
         for( i = 0; i < BUFFER; i++)
         the_buffer[i] = 'A';    
      
         //setup sockets
         int testsocket;        
         struct sockaddr_in thetarget;  
         testsocket = socket(AF_INET, SOCK_STREAM, 0);  

         thetarget.sin_family = AF_INET; //always AF_INET        
         thetarget.sin_port = htons(TESTPORT); // *TESTPORT is argv[2]         
         thetarget.sin_addr.s_addr = inet_addr(TARGETIP); // TARGETIP is argv[1]
        
         connect(testsocket, (struct sockaddr *)&thetarget, sizeof(struct sockaddr)); // make the connection
         send(testsocket, the_buffer, strlen(the_buffer), 0);  // send the buffer
         
         while (1) {
         recv(testsocket, return_data, strlen(the_buffer), 0); // put the length of he_buffer 1024 into return_data     
         printf("%s\n", return_data); 
        }

         perror("connect"); 
}

void display_usage(void)
{
       fprintf(stderr, "Usage: ./connect 127.0.0.1 9999\n" );
}

-Thanks in advance

A fix....

Code:

int iPort;
//Assuming argv[2] is port number
iPort = atoi(argv[2]);
 thetarget.sin_port = htons(iPort);

htons needs an integer to convert from host byte order to network byte order. Any type of character array won't work.

Have fun

Bob

Thanks a million, got it working now.