z/TPF - Group home

#include <cdf.h>
#include <tpf/tpfapi.h>
// my_df_database.h defines the format of the z/TPFDF database that we are working with.
#include <my_df_database_type.h>

int ABCD()
{
  struct wtopc_header header_buffer;
  char msgText[256];

  // "my_lrec_type" is a structure representing the format of an LREC.
  // This structure should be defined in both a DSECT and a C header (my_df_database.h).
  // This LREC contains standard z/TPFDF fields, and only contains one user-defined
  //   field: a name.
  struct my_lrec_type *lrec;

  // Define the file ID that you are going to open.
  // You have to send a pointer to this value to dfopn(), so you cannot pass the
  //   literal value in. You must define a local variable containing the value.
  dft_fid fileID[2] = "\xB4\x31";
  
  // Open a subfile.
  // dfopn_acc accepts the following parameters: 
  // dft_ref *ref_name: Reference name of the file you are opening.
  // dft_fid *id      : File ID of the file you are opening.
  // dft_opt access   : The method you want to use to access the subfile.
  // dft_opt options  : Options for processing the subfile.
  // dft_xxx acc      : Identifying data used to access the subfile.
  // We are accessing by using the DFOPN_ORD option to open the first
  //   ordinal (or the first subfile) in the file.
  // By specifying 0 for the options parameter, we are telling z/TPFDF
  //   not to perform any special behavior when opening the subfile.
  dft_fil *sw00sr = dfopn_acc("DR31BI", fileID, DFOPN_ORD, 0, 1);
  
  // DF_ER is a macro provided by z/TPFDF that checks if an error has been
  //   indicated in the SW00SR's sw00rtn field.
  // If an error occurred while opening the subfile, print a message and exit.
  if (DF_ER(sw00sr))
  {
    wtopc_insert_header(&header_buffer, "ABCD", 1, WTOPC_ERROR, WTOPC_SYS_TIME);
    wtopc("An error occurred while opening the subfile.",
          WTOPC_EBROUT | WTOPC_PRC,
          WTOPC_NO_CHAIN,
          &header_buffer);
     exit(1);
  }

  // Read an LREC from the subfile.
  // dfred() accepts the following parameters:
  // dft_fil *file  : The pointer to the SW00SR that you want to read from.
  // dft_opt options: Options for processing the subfile.
  // dfred() returns a pointer to a dft_rec structure.
  // We can cast that to a my_lrec_type structure, as long as my_lrec_type is
  //   defined properly.
  lrec = (struct my_lrec_type *) dfred(sw00sr, 0);

  // In contrast to DF_ER, DF_OK checks that an error has NOT occurred.
  // So, this loop will keep reading until it encounters an error.
  // One of these "error" conditions could be that there are no records left in
  //   the subfile. We will check for that condition later.
  while (DF_OK(sw00sr))
  {
    // Because we've casted the LREC to our my_lrec_type structure, we can
    //  look at the fields that we've defined within it.
    sprintf(msgText, "Name: %s", lrec->vLrec.v3rec._name);
    // Print the name.
    wtopc_insert_header(&header_buffer, "ABCD", 2, WTOPC_INFO, WTOPC_SYS_TIME);
    wtopc(msgText, WTOPC_EBROUT | WTOPC_PRC, WTOPC_NO_CHAIN, &header_buffer);
    
    // Read the next LREC.
    lrec = (struct my_lrec_type *) dfred(sw00sr, 0);
  }

  // We've exited the while loop, so we have some kind of "error" condition.
  // Check if it's a real error, or if we've just run out of records to read.
  // DF_NR checks if there are no records to read.
  if (!(DF_NR(sw00sr)))
  {
    // We're not out of records; this is a real error.
    wtopc_insert_header(&header_buffer, "ABCD", 3, WTOPC_ERROR, WTOPC_SYS_TIME);
    wtopc("An error occurred while reading the subfile.",
          WTOPC_EBROUT | WTOPC_PRC,
          WTOPC_NO_CHAIN,
          &header_buffer);
  }

  // Close the subfile.
  // dfcls() accepts the following parameters:
  // dft_fil *file  : The pointer to the SW00SR that you want to close.
  // dft_opt options: Options for processing the subfile.
  // dfcls will never return any error indicators, so there is nothing to check.
  dfcls(sw00sr, 0);

  return 0;
}

#include <cdf.h>
#include <tpf/tpfapi.h>
#include <my_df_database.h>

int ABCD()
{
  struct wtopc_header header_buffer;
  struct my_lrec_type lrec;
  char *my_name = "Jane Doe";

  // Open a subfile.
  dft_fil *sw00sr = dfopn_acc("DR26BI", "B426", DFOPN_ORD, 0, 1);
  if (DF_ER(sw00sr))
  {
    wtopc_insert_header(&header_buffer, "ABCD", 1, WTOPC_ERROR, WTOPC_SYS_TIME);
    wtopc("An error occurred while opening the subfile.",
          WTOPC_EBROUT | WTOPC_PRC, WTOPC_NO_CHAIN, &header_buffer);
    exit(1);
  }

  // Set up the in-memory copy of an LREC.
  // Each LREC will usually contain a size and key field.
  lrec._siz = strlen(my_name) + sizeof(dft_siz) + sizeof(dft_pky);
  lrec._key = 0x80;
  strcpy(lrec.vLrec._nam, my_name);

  // Add the LREC to the subfile.
  dfadd(sw00sr, DFADD_NEWLREC, 0, &lrec);
  // Verify return value and print an error or success message accordingly.
  if (DF_ER(sw00sr))
  {
    wtopc_insert_header(&header_buffer, "ABCD", 2, WTOPC_ERROR, WTOPC_SYS_TIME);
    wtopc("An error occurred while adding an LREC.",
          WTOPC_EBROUT | WTOPC_PRC, WTOPC_NO_CHAIN, &header_buffer);
  }
  else
  {
    wtopc_insert_header(&header_buffer, "ABCD", 3, WTOPC_INFO, WTOPC_SYS_TIME);
    wtopc("Successfully added an LREC.",
          WTOPC_EBROUT | WTOPC_PRC, WTOPC_NO_CHAIN, &header_buffer);
  }

  dfcls(sw00sr, 0);

  return 0;
}