Help for GT2TCL

PURPOSE:
gt2tcl gets a value (int, double, or string) and puts it into
a TAE TCL variable.  The value is a GeoTIFF parameter in the
VICAR label.  These are always found in the VICAR state label
under the property "GEOTIFF".

If the selection is not found, or wrong type, etc., a special value
of -999 (int) -999.0 (real) or "-999" (character string) is output
to the TAE TCL variable.

Multiple occurrences of the GeoTIFF keyword are selected by the
parameter element (since VICAR calls these elements) and which 
item in a vector is handled by the parameter sequence.
EXECUTION:

Examples

gt2tcl AUSTRALIA val=s1 keyword=GTRASTERTYPEGEOKEY vtype=0

          gets the rastertype from the file AUSTRALIA and puts
          into the TCL variable s1 as a string

gt2tcl AUSTRALIA val=n1 keyword=GTRASTERTYPEGEOKEY vtype=4

          gets the rastertype from the file AUSTRALIA and puts
          into the TCL variable n1 as an integer (converts
          the string to an integer)

OPERATION:
gt2tcl reads the part of the VICAR label that contains the
GeoTIFF information and tries to find the keyword (case 
insensitive).   When found, the value is placed in the output
parameter.  Type conversion is performed according to the user
request in the parameter vtype.

Any errors cause -999 (int), -999.0 (real), or "-999" (string)
to  be placed in the output parameter.
 TIMING: 

Less than one second.  

 ORIGINAL PROGRAMMER:    A. Zobrist          03 June 2000
 COGNIZANT PROGRAMMER:   Barbara McGuffie    03 June 2000
 
 REVISION HISTORY
  2000-06-03 AZ  Initial version
  2007-12-28 WLB Switched to USES_ANSI_C AND LIB_CARTO; misc cleanup
  2015-11-01 WLB Migrated to MIPL