Procedure

   SpiceBoolean exists_c ( ConstSpiceChar  * fname )

Abstract

   Determine whether a file exists.

Required_Reading

   None.

Keywords

    FILES

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   fname      I   Name of the file in question.

   The function returns the value SPICETRUE if the file exists,
   SPICEFALSE otherwise.

Detailed_Input

   fname        is the name of the file in question. This may be
                a system name, e.g.

                      "DISK:[USER.SUB1.SUB2]DATA.DAT"
                      "\usr\dir1\dir2\data.dat"

                or a logical name, e.g.

                      "EPHEMERIS"
                      "DATA$DIR:SAMPLE.DAT"

Detailed_Output

   The function returns the value SPICETRUE if the file exists,
   SPICEFALSE otherwise.

Parameters

   None.

Exceptions

   1) If the input name is blank, the error SPICE(BLANKFILENAME) will
      be signalled. (This test is currently unimplemented.)

   2) If an error occurs during the execution existence test,
      the error SPICE(INQUIREFAILED) is signalled.

Files

   None.

Particulars

   Uses the f2c I/O libraries to implement the existence test.

Examples

   The following code fragment illustrates the use of exists_c.

      if ( exists_c ( file ) )
         {
         update ( file );
         }
      else
         {
         setmsg_c ( "Input file does not exist." );
         sigerr_c ( "FILENOTFOUND"               );
         return;
         }

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   K.R. Gehringer  (JPL)
   H.A. Neilan     (JPL)
   I.M. Underwood  (JPL)

Version

   -CSPICE Version 1.1.0, 08-FEB-1998 (NJB)

       References to C2F_CreateStr_Sig were removed; code was
       cleaned up accordingly.  String checks are now done using
       the macro CHKFSTR_VAL.

   -CSPICE Version 1.0.0, 25-OCT-1997 (NJB)

       Based on SPICELIB Version 2.1.0, 4-MAR-1996 (KRG)

Index_Entries

   does the file exist

Link to routine exists_c source file exists_c.c