Resource Types
xdiff Functions
xdiff
PHP Manual

# Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

`XDIFF_PATCH_NORMAL` (integer)
  This flag indicates that xdiff_[string|file]_patch functions should create result by applying patch to original content thus creating newer version of file. This is the default mode of operation.
`XDIFF_PATCH_REVERSE` (integer)
  This flag indicated that xdiff_[string|file]_patch functions should create result by reversing patch changed from newer content thus creating original version.

Resource Types
xdiff Functions
xdiff
PHP Manual