Metrologic Optimus R, Руководство по программированию

Страница: 196 / 241

190 "C" Programming Guide For Optimus S/R
int fd; /* file handle of the target DAT file */
long size; /* new size of file in bytes */
Example if (chsize (fd, 0L)) puts ("file is truncated!\n");
Description This routine extends or truncates a DAT file ( fd ) to match the new file length in
bytes given in the argument
size
.
If the file is truncated, all data beyond the new file size will be lost.
If the file is extended, no initial value is filled to the newly extended area.
Return If successful, it returns 1.
On error, it returns 0.
An error code is set to the global variable fErrorCode to indicate the error
condition encountered. Below are possible error codes and their interpretation.
Error Code Interpretation
2 File specified by fd does not exist.
4 File specified by
fd
is not a DAT file.
7 Invalid file handle.
8 File not opened.
10 No free file space for file extension.
close
Purpose To close a DAT file.
Syntax int close (int fd);
int fd; /* file handle of the target DAT file */
Example if (close (fd)) puts ("file is closed!\n");
Description This routine closes a previously opened or created DAT file ( fd ).
Return If successful, it returns 1.
On error, it returns 0.
An error code is set to the global variable fErrorCode to indicate the error
condition encountered. Below are possible error codes and their interpretation.
Error Code Interpretation
2 File specified by fd does not exist.
4 File specified by
fd
is not a DAT file.
7 Invalid file handle.
8 File not opened.
See Also
open