schema.c

/* File name: schema.c */
#include "common.h"
int main() {
  J i;
  I handle;
  I portnumber= 5010;
  S hostname= "localhost";
  S usernamePassword= "kdb:pass";
  K response, table, columnNames;

  handle= khpu(hostname, portnumber, usernamePassword);
  if(!handleOk(handle)) {
    m9();
    return EXIT_FAILURE;
  }
  response= k(handle, ".u.sub[`trade;`]", (K) 0);
  if(isRemoteErr(response)) {
    kclose(handle);
    m9();
    return EXIT_FAILURE;
  }
  // .u.sub returns a two element list
  // containing the table name and schema
  // q)h:hopen 5010
  // q)h".u.sub[`trade;`]"
  // `trade
  // +`time`sym`price`size!(();();();())
  if(response->t != 0 || response->n != 2 || kK(response)[0]->t != -KS ||
     kK(response)[1]->t != XT) {
    fprintf(stderr,
            "Subscription response is of unknown shape. Top level type is %d\n",
            response->t);
    r0(response);
    kclose(handle);
    m9();
    return EXIT_FAILURE;
  }
  printf("Number of elements returned is %lld\n", response->n);
  printf("Table name: %s\n", kK(response)[0]->s);

  table= kK(response)[1]->k;
  columnNames= kK(table)[0];

  printf("Num colNames: %lld\n", columnNames->n);
  for(i= 0; i < columnNames->n; i++) {
    printf("Column %lld is named %s\n", i, kS(columnNames)[i]);
  }

  r0(response);
  kclose(handle);
  m9();
  return EXIT_SUCCESS;
}