TestFileNbr

Determine the status of a file number.

Short Name

TSTFILNUM()

Type

Low-level function

Declaration

COUNT TestFileNbr(COUNT filno)

Description

TestFileNbr() returns zero if filno is not in use or returns FINT_ERR (47, c-tree Plus not initialized), FNUM_ERR (22, filno is out of range), or FUSE_ERR (46, filno is in use). TestFileNbr() does NOT set or change uerr_cod.

Return

Value	Symbolic Constant	Explanation
0	NO_ERROR	File number not in use.
22	FNUM_ERR	filno is out of range.
46	FUSE_ERR	filno is in use.
47	FINT_ERR	c-tree Plus not initialized.

See c-tree Plus Error Codes for a complete listing of valid c-tree Plus error values.

Example

COUNT    retval;


if (retval = InitISAM(6,7,4))

    printf("\nCould not initialize. Error %d.", retval);

else {

    if ((retval = TestFileNbr(5)) == 0) {

        if (OpenRFile(5, "MyFile.dat"))

            printf("\nCould not open files.");

    else if (retval == 46)

        if (OpenRFile(-1, "MyFile.dat"))

            printf("\nCould not open files.");

    if (CloseISAM())

        printf("\nCould not close ISAM.");