Create Findwgrib2.cmake

Modules/Findwgrib2.cmake

@@ -0,0 +1,42 @@
+# This module produces the target wgrib2::wgrib2
+
+find_path(WGRIB2_INCLUDES wgrib2api.mod)
+find_library(WGRIB2_LIB libwgrib2.a)
+find_library(WGRIB2_API_LIB libwgrib2_api.a)
+
+add_library(wgrib2::wgrib2 UNKNOWN IMPORTED)
+
+# Library builds are different between CMake build and the make build.
+# libwgrib2_api.a is only necessary in the CMake build and must come first when linking
+if(WGRIB2_API_LIB)
+  # CMake build. Need both.
+  set(first_lib ${WGRIB2_API_LIB})
+  set(second_lib ${WGRIB2_LIB})
+else()
+  # Makefile build. Only need libwgrib2.a
+  set(FIRST_LIB ${WGRIB2_LIB})
+  set(second_lib "")
+endif()
+
+set_target_properties(wgrib2::wgrib2 PROPERTIES
+  IMPORTED_LOCATION "${first_lib}"
+  INTERFACE_INCLUDE_DIRECTORIES "${WGRIB2_INCLUDES}"
+  INTERFACE_LINK_LIBRARIES "${second_lib}")
+
+set(WGRIB2_LIBRARIES "${first_lib}" "${second_lib}")
+
+find_program(WGRIB2_EXE wgrib2)
+execute_process(COMMAND ${WGRIB2_EXE} --version OUTPUT_VARIABLE version_str)
+
+# Wgrib2 changed how it output --version from "v0.x.y.z" to "vx.y.z" starting in wgrib2 3.0
+if(version_str MATCHES "^v0.*")
+  string(SUBSTRING "${version_str}" 3 5 version)
+else()
+  string(SUBSTRING "${version_str}" 1 5 version)
+endif()
+
+find_package_handle_standard_args(wgrib2
+  REQUIRED_VARS WGRIB2_LIBRARIES WGRIB2_INCLUDES WGRIB2_EXE
+  VERSION_VAR version
+  )
+