file: add SIZE option

This commit adds the SIZE option to file(). It returns the file size of
the given path if it exists and produces an error if not.

2 files changed, 16 insertions, 0 deletions

diff --git a/Help/command/file.rst b/Help/command/file.rst
index f5279c0..26a9ae2 100644
--- a/Help/command/file.rst
+++ b/Help/command/file.rst
@@ -25,6 +25,7 @@ Synopsis
     file({`REMOVE`_ | `REMOVE_RECURSE`_ } [<files>...])
     file(`MAKE_DIRECTORY`_ [<dir>...])
     file({`COPY`_ | `INSTALL`_} <file>... DESTINATION <dir> [...])
+    file(`SIZE`_ <filename> <out-var>)
 
   `Path Conversion`_
     file(`RELATIVE_PATH`_ <out-var> <directory> <file>)
@@ -333,6 +334,16 @@ and ``NO_SOURCE_PERMISSIONS`` is default.
 Installation scripts generated by the :command:`install` command
 use this signature (with some undocumented options for internal use).
 
+.. _SIZE:
+
+.. code-block:: cmake
+
+  file(SIZE <filename> <variable>)
+
+Determine the file size of the ``<filename>`` and put the result in
+``<variable>`` variable. Requires that ``<filename>`` is a valid path
+pointing to a file and is readable.
+
 Path Conversion
 ^^^^^^^^^^^^^^^
 
diff --git a/Help/release/dev/file-size.rst b/Help/release/dev/file-size.rst
new file mode 100644
index 0000000..4f0e196
--- /dev/null
+++ b/Help/release/dev/file-size.rst
@@ -0,0 +1,5 @@
+file-size
+---------
+
+* The :command:`file` command gained a ``SIZE`` mode to get the size
+  of a file on disk.