Question

calling gethostname with a char pointer

Asked by: Johannne1

when I call gethostbyname using argv[1], I have no problem but when
I pass as a pointer and call gethostname I have assignment makes pointer
from integer without a cast.

have a main function where I do:
 
        struct hostent *he;
        struct in_addr address;
        he = gethostbyname(argv[1]);
        if (he)
        {
          address =  *((struct in_addr*) he->h_addr);
          printf("Setting destination to  %s\n", inet_ntoa( address));
          if (cppError = cppSetDestination(cppInstance,inet_ntoa( address)) != 0 )
          {
                  printf("Error setting destination, code %d.\n", cppError);
                  return 1;
          }
        }
        else
        {
          printf("Could not resolve hostname: %s\n",argv[1]);
          return 1;
        }
 
 
I have no problem with the above.
Later I call a function and pass argv[1] and want to use gethostname..
 
        if (cppError = cppSetNewFastest(cppInstance, argv[4], &fastest, argv[1] ,argv[2], argv[3] ) != 0 )
        {
            printf("Error finding the fastest IP, code %d.\n", cppError);
            return 1;
        }
 
In function cppSetNewFastest
 
int cppSetNewFastest(void * cppInstance, char qryNum[], int * fastestPtrHost, char * ptrHost1 ,char * ptrHost2, char * ptrHost3 )
:
:
       
        printf("Enter  cppSetNewFastest - 1 \n\n\n");
 
        struct hostent *he;
        struct in_addr address;
        
        he = gethostbyname(ptrHost1);
 
        printf("Back from gethost - 1 \n\n\n");
        if (he)
        {
          address =  *((struct in_addr*) he->h_addr);
          if (cppError = cppSetDestination(cppInstance,inet_ntoa(address)) != 0 )
          {
                  printf("Error setting destination, code %d.\n", cppError);
                  return 1;
          }
        }
        else
        {
          printf("Could not resolve hostname: %s\n",ptrHost1);
          return 1;
        }
 
        printf("Back from assigning address - 1 \n\n\n");
 
 
The above  he = gethostbyname(ptrHost1); gives:
warning: assignment makes pointer from integer without a cast
The above address =  *((struct in_addr*) he->h_addr); gives error
error: dereferencing pointer to incomplete type
 
I also tried receiving argv[1] as an array but this did not work either...
 
int cppSetNewFastest(void * cppInstance, char qryNum[], int * fastestPtrHost, char ptrHost1 [] ,char * ptrHost2, char * ptrHost3 )
:
:
      int number_host1;
        number_host1 = 0;
        number_host1 = strlen(qryNum);
         
        
        printf("Enter  cppSetNewFastest - 1 \n\n\n");
 
        struct hostent *he;
        struct in_addr address;
        
        he = gethostbyname(ptrHost1,number_host1);
 
        printf("Back from gethost - 1 \n\n\n");
        if (he)
        {
          address =  *((struct in_addr*) he->h_addr);
          if (cppError = cppSetDestination(cppInstance,inet_ntoa(address)) != 0 )
          {
                  printf("Error setting destination, code %d.\n", cppError);
                  return 1;
          }
        }
        else
        {
          printf("Could not resolve hostname: \n");
          return 1;
        }
 
        printf("Back from assigning address - 1 \n\n\n");
 
 
I get errors:
 
warning: assignment makes pointer from integer without a cast
error: dereferencing pointer to incomplete type
warning: passing arg 2 of `cppSetDestination' makes pointer from integer without a cast

                                  
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Asked On
2009-08-20 at 06:54:44ID24668132
Tags

c programming UDP

Topic

C Programming Language

Participating Experts
3
Points
500
Comments
5

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Answers

 

by: nuke3ddPosted on 2009-08-20 at 07:01:07ID: 25142591

Is this function (cppSetNewFastest) in a new file? If so, did you include all the required files?

 

by: Infinity08Posted on 2009-08-20 at 07:01:36ID: 25142596

Have you included the socket header file where you implemented the cppSetNewFastest function ?

 

by: masheikPosted on 2009-08-20 at 07:12:54ID: 25142733

I think this error comes If  the line of code is in a .c file which does NOT have the necessary .h file included.

 

by: Johannne1Posted on 2009-08-20 at 07:34:18ID: 31618130

Thanks a lot! It is a new file and I forgot to include the libraries! I kept staring at the problem and the compiler warning and error were so weird.

 

by: Johannne1Posted on 2009-08-20 at 07:36:17ID: 25143043

Hi Infinity08 and Masheik,
You're right I forgot to include the socket header file and kept staring at the compiler error.
Thanks a lot.

20120131-EE-VQP-002

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