c - Simple calculator with rpcgen -

i new in programming in c. try create small , simple program addition of 2 integers file calculs.x

here, contents of file calculs.x

/* calculs.x*/  struct data_in {     int arg1;     int arg2; }; typedef struct data_in data_in;  struct result_int {     int result;     int errno; };  struct result_float {     int result;     int errno; };  typedef struct result_int result_int; typedef struct result_float result_float;  program calculs{     version version_un{         void calculs_null(void) = 0;         result_int add (data_in) = 1;         result_int sub(data_in) = 2;         result_int mul(data_in) = 3;         result_float div (data_in) = 4;     } = 1; } = 0x20000001; 

for first time, created file calculs.c client:

#include <rpc/rpc.h> #include "calculs.h"  int main(int argc, char *argv[]) {     int buffer[256];     struct data_in input;     struct result_int *output;     client *cl;      if (argc != 2) {         printf("usage: client hostname_of_server\n");         exit(1);     }      /*etablir le lien vers le serveur distant      * cl = clnt_create(server, prog, vers, prot);      */     cl = clnt_create(argv[1], calculs, version_un, "tcp");     if (cl == null) {         clnt_pcreateerror(argv[1]);         exit(1);     }      input.arg1 = 5;     input.arg2 = 5;      output = add_1(&input, cl);     if (output == null) {         clnt_perror(cl, argv[1]);         exit(1);     }     printf("the result field %d\n", output->result);     printf("the errno field %d\n", output->errno);      clnt_destroy(cl);      return 0; } 

i have not received error compiling file, rcalculs.c file, can not compile. here file contents rcalculs.c:

#include <rpc/rpc.h> #include "calculs.h"  result_int *add_1(struct data_in data, struct svc_req *rqstp) {     int buffer;     struct result_int result;     int = data.arg1;     int b = data.arg2;     buffer = a+b;     result.result = buffer;     result.errno =0;     return result; } 

the message error compiling is

rcalculs.c:11:13: erreur: conflicting types ‘add_1’ in file included rcalculs.c:9:0: calculs.h:46:22: note: previous declaration of ‘add_1’ here rcalculs.c: in function ‘add_1’: rcalculs.c:19:5: erreur: incompatible types when returning type ‘struct result_int’ ‘struct result_int *’ expected 

could me resolve problem, please?

erreur: conflicting types ‘add_1 

this error because did not declare add_1() function. , when ever made function call add_1() treats declaration.

add line before main()

  result_int *add_1(struct data_in data, struct svc_req *rqstp); 

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rcalculs.c:19:5: erreur: incompatible types when returning type ‘struct result_int’ ‘struct result_int *’ expected

  result_int * add_1(struct data_in data, struct svc_req *rqstp) {     int buffer;     struct result_int result; //here declare pointer     int = data.arg1;     int b = data.arg2;     buffer = a+b;     result.result = buffer; //change here     result.errno =0;        //change here      return result; //here returning struct result_int type required struct result_int * type     } 

return pointer. , changes accordingly in function.

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output = add_1(&input, cl); //here passing reference of input need pass input.