FREWIND

FREWIND

Positions the file pointer at the beginning of the file

Category: External File

Syntax
Details
Example
See Also

Syntax

sysrc=FREWIND(file-id);

sysrc

contains the return code for the operation:

0	successful
0	not successful

Type: Numeric

file-id

contains the identifier that was assigned when the file was opened. If file-id is invalid, the program halts.

Type: Numeric

Details

FREWIND has no effect on a file that was opened with sequential access.

Example

Assign the fileref THEFILE to an external file. Then open the file and read the records until the end of the file is reached. The FREWIND function then repositions the pointer to the beginning of the file. The first record is read again and is stored in the File Data Buffer (FDB). The first token is retrieved and is stored in the variable VAL.

   /* Assign the fileref THEFILE to the physical */
   /* filename stored in the variable FNAME      */
   /* and open it.                               */
rc=filename('thefile',fname);
fileid=fopen('thefile');
do while (rc ne -1);
      /* Read a record. */
   rc=fread(fileid);
end;

   /* Reposition the pointer at the beginning of */
   /* the file.                                  */
if rc= -1  then rc=frewind(fileid);
   /* Read the first record. */
rc=fread(fileid);
   /* Read the first token into VAL. */
rc=fget(fileid,val);
put val= ;
rc=fclose(fileid);
rc=filename('thefile','');

See Also

FGET

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