remove lsb_release from cmake as a required dependency (#14)

* fix #10
remove lsb_release as a required dependency

* fix configure errors

* fix execute_process

* fix grep ID

CMakeLists.txt

@@ -27,14 +27,9 @@ endif()
 set(CATCH_LIBS_ALIASES Catch2::Catch2 Catch2::Catch2WithMain)
 
 function(get_linux_lsb_release_information)
-    find_program(LSB_RELEASE_EXEC lsb_release)
-    if(NOT LSB_RELEASE_EXEC)
-        message(FATAL_ERROR "Could not detect lsb_release executable, can not gather required information")
-    endif()
-
-    execute_process(COMMAND "${LSB_RELEASE_EXEC}" --short --id OUTPUT_VARIABLE LSB_RELEASE_ID_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
-    execute_process(COMMAND "${LSB_RELEASE_EXEC}" --short --release OUTPUT_VARIABLE LSB_RELEASE_VERSION_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
-    execute_process(COMMAND "${LSB_RELEASE_EXEC}" --short --codename OUTPUT_VARIABLE LSB_RELEASE_CODENAME_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process(COMMAND sh -c "cat /etc/*release | grep -w ID | cut -d'=' -f 2" OUTPUT_VARIABLE LSB_RELEASE_ID_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process(COMMAND sh -c "cat /etc/*release | grep ^VERSION_ID | cut -d'=' -f 2" OUTPUT_VARIABLE LSB_RELEASE_VERSION_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process(COMMAND sh -c "cat /etc/*release | grep ^VERSION_CODENAME | cut -d'=' -f 2" OUTPUT_VARIABLE LSB_RELEASE_CODENAME_SHORT OUTPUT_STRIP_TRAILING_WHITESPACE)
 
     set(LSB_RELEASE_ID_SHORT "${LSB_RELEASE_ID_SHORT}" PARENT_SCOPE)
     set(LSB_RELEASE_VERSION_SHORT "${LSB_RELEASE_VERSION_SHORT}" PARENT_SCOPE)