Example: Working with stream files
This ILE C program writes data from an existing stream file to a new database file.
The program uses the following hierarchical file system (HFS) APIs:
- Create Directory (QHFCRTDR)
- Open Stream File (QHFOPNSF)
- Read from Stream File (QHFRDSF)
- Close Stream File (QHFCLOSF)
Note: By using the code examples, you agree to the terms of the Code license and disclaimer information.
/********************************************************************/
/* Program Name: HFSCOPY */
/* Language : ILE C */
/* Description : This program will do the following: */
/* -- Create or replace a stream file */
/* -- Create or replace a database file */
/* -- Read from the stream file and write to the */
/* database file until EOF */
/* -- Close both files when done */
/* APIs Used : QHFCRTDR, QHFOPNSF, QHFRDSF, QHFCLOSF */
/********************************************************************/
/********************************************************************/
/* Include files */
/********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <qhfopnsf.h>
#include <qhfrdsf.h>
#include <qhfclosf.h>
#include <qhfcrtdr.h>
#include <qusec.h>
/********************************************************************/
/* Structure and variable definitions */
/********************************************************************/
#define ON 1
#define OFF 0
typedef struct error_code_struct {
Qus_EC_t EC;
char exception_data[256];
}error_code_struct;
error_code_struct error_code;
char file_handle[16];
char path_name[30];
char open_info[10];
char attrib_info;
char action;
char read_buffer[80];
int path_length;
int attrib_length = 0;
int bytes_to_read;
int bytes_read = 0;
int end_file;
int cmpgood;
FILE *FP;
/*********************************************************************/
/*printErrCode: Routine to print the error code structure */
/*********************************************************************/
void printErrCode(error_code_struct *theErrCode)
{
int i;
char *tempptr = theErrCode->EC.Exception_Id;
printf("Bytes Provided -> %d\n",theErrCode->EC.Bytes_Provided);
printf("Bytes Available -> %d\n",theErrCode->EC.Bytes_Available);
printf("Exception ID -> ");
for (i=0;i<7 ;i++,tempptr++ )
{
putchar(*tempptr);
}
putchar('\n');
}
/********************************************************************/
/* Start of code */
/********************************************************************/
main()
{
error_code.EC.Bytes_Provided = 116;
/********************************************************************/
/* Create the directory */
/********************************************************************/
strcpy(path_name,"/QDLS/HFSFLR");
path_length = strlen(path_name);
QHFCRTDR(path_name,path_length,&attrib_info,attrib_length,&error_code);
if ( error_code.EC.Bytes_Available != 0 )
{
if (!memcmp(error_code.EC.Exception_Id,"CPF1F04",7))
printf("Directory HFSFLR already created.\n");
else
{
printErrCode(&error_code);
exit(1);
}
}
/********************************************************************/
/* Open the stream file */
/********************************************************************/
strcpy(open_info,"210 120 "); /* Create or replace the file */
strcpy(path_name,"/QDLS/HFSFLR/SAMPLE.HFS");
path_length = strlen(path_name);
printf("OPEN STREAM FILE:\n ");
QHFOPNSF(&file_handle,
path_name,
path_length,
open_info,
&attrib_info,
attrib_length,
&action,
&error_code);
if (error_code.EC.Bytes_Available != 0)
{
printErrCode(&error_code);
exit(1);
}
/********************************************************************/
/* Open a database file */
/********************************************************************/
system("CRTLIB LIB(HFSLIB)");
if (( FP = fopen("HFSLIB/HFSFILE(SAMPLE)","wb")) == NULL)
{
printf("Cannot open HFSLIB/HFSFILE(SAMPLE)\n");
exit(1);
}
/********************************************************************/
/* Loop through reading from the stream file and writing to the */
/* database file. */
/********************************************************************/
end_file = OFF;
while (end_file == OFF)
{
/*************************************************************/
/* Read 80 bytes from the stream file */
/*************************************************************/
bytes_to_read = 80;
printf("READ STREAM FILE:\n ");
QHFRDSF(&file_handle,
read_buffer,
bytes_to_read,
&bytes_read,
&error_code);
if (error_code.EC.Bytes_Available != 0)
{
cmpgood = strncmp("CPF1F33",error_code.EC.Exception_Id,7);
if (cmpgood != 0)
printErrCode(&error_code);
end_file = ON;
}
else
{
printf("BYTES READ: %d\n ",bytes_read);
printf("READ BUFFER: %s\n",read_buffer);
if (bytes_read < bytes_to_read)
{
end_file = ON;
/*******************************************************/
/* Write remaining bytes to the database file */
/*******************************************************/
if (bytes_read > 0)
fwrite(read_buffer,1,bytes_read,FP);
}
}
}
/********************************************************************/
/* Close the stream file */
/********************************************************************/
printf("CLOSE STREAM FILE:\n ");
QHFCLOSF(&file_handle,
&error_code);
if (error_code.EC.Bytes_Available != 0)
printErrCode(&error_code);
/********************************************************************/
/* Close the database file */
/********************************************************************/
fclose(FP);
}
To create the program using ILE C, specify the following:
CRTBNDC PGM(QGPL/HFSCOPY) SRCFILE(QGPL/QCSRC)