DBReadHistory()

Description

DBReadHistory() is used to read a history record.

Call Signature

string DBReadHistory ( int/string filespec, string layer_type, int layer_index [, int history_rev] )

Return Value

string

The history record string or an empty string if there there is no history record matching the request.

Arguments

int/string filespec:

This can either be the handle returned by DBOpen(), or the name of an open file.

string layer_type:

The name of the type of layer. This is either "FIL" for the overall file, "IMG" for an image channel or one of the segment types listed in DBNextSeg().

int layer_index:

The channel, or segment number. Ignored if layer_type is "FIL".

[ int history_rev ]:

If this argument is present, this is used to specify which history number to fetch. This should be 1 to fetch the most recent history record, or a higher number for an older history record. If missing, the most recent history record is returned.

Remarks

Most formats, including PCIDSK, have at most eight history records per layer.

See also

GDB file functions

DBWriteHistory()