Format
#include <recio.h>
_RIOFB_T *_Rwrread(_RFILE *fp, void *in_buf, size_t in_buf_size,
void *out_buf, size_t out_buf_size);Language Level: ILE C Extension
Threadsafe: No.
Description
The _Rwrread() function performs a write and then a read operation on the file that is specified by fp. Separate buffers may be specified for the input and output data. The minimum of size and the length of the current record format determines the amount of data to be copied between the system buffer and the buffers for both the write and read parts of the operation. If out_buf_size is greater than the record length of the current format, errno is set to ETRUNC on the write part of the operation. If in_buf_size is less than the length of the current record format, errno is set to ETRUNC on the read part of the operation.
The _Rwrread() function is valid for display and ICF files.
Return Value
The _Rwrread() function returns a pointer to the _RIOFB_T structure that is associated with fp. If the _Rwrread() operation is successful, the num_bytes field is set to the number of bytes transferred from the system buffer to in_buf in the read part of the operation (move mode) or the record length of the file (locate mode).
The value of errno may be set to:
See Table 12 and Table 14 for errno settings.
Example that uses _Rwrread()
#include <stdio.h>
#include <recio.h>
#include <string.h>
#include <stdlib.h>
typedef struct {
char name[20];
char address[25];
} format1 ;
typedef struct {
char name[8];
char password[10];
} format2 ;
typedef union {
format1 fmt1;
format2 fmt2;
} formats ;
int main(void)
{
_RFILE *fp; /* File pointer */
_RIOFB_T *rfb; /*Pointer to the file's feedback structure */
formats buf, in_buf, out_buf; /* Buffers to hold data */
/* Open the device file. */
if (( fp = _Ropen ( "MYLIB/T1677RD2", "ar+" )) == NULL )
{
printf ( "Could not open file\n" );
exit ( 1 );
}
_Rpgmdev ( fp,"DEVICE2" );/* Change the default program device. */
/* Replace with actual device name. */
_Rformat ( fp,"FORMAT2" ); /* Set the record format for the */
/* display file. */
rfb = _Rwrite ( fp, "", 0 ); /* Set up the display. */
rfb = _Rwriterd ( fp, &buf, sizeof(buf) );
rfb = _Rwrread ( fp, &in_buf, sizeof(in_buf), &out_buf,
sizeof(out_buf ));
/* Continue processing. */
_Rclose ( fp );
}Related Information