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+:orphan:
+
+==========================================================
+ ceph-diff-sorted -- compare two sorted files line by line
+==========================================================
+
+.. program:: ceph-diff-sorted
+
+Synopsis
+========
+
+| **ceph-diff-sorted** *file1* *file2*
+
+Description
+===========
+
+:program:`ceph-diff-sorted` is a simplifed *diff* utility optimized
+for comparing two files with lines that are lexically sorted.
+
+The output is simplified in comparison to that of the standard `diff`
+tool available in POSIX systems. Angle brackets ('<' and '>') are used
+to show lines that appear in one file but not the other. The output is
+not compatible with the `patch` tool.
+
+This tool was created in order to perform diffs of large files (e.g.,
+containing billions of lines) that the standard `diff` tool cannot
+handle efficiently. Knowing that the lines are sorted allows this to
+be done efficiently with minimal memory overhead.
+
+The sorting of each file needs to be done lexcially. Most POSIX
+systems use the *LANG* environment variable to determine the `sort`
+tool's sorting order. To sort lexically we would need something such
+as:
+
+        $ LANG=C sort some-file.txt >some-file-sorted.txt
+
+Examples
+========
+
+Compare two files::
+
+        $ ceph-diff-sorted fileA.txt fileB.txt
+
+Exit Status
+===========
+
+When complete, the exit status will be set to one of the following:
+
+0
+  files same
+1
+  files different
+2
+  usage problem (e.g., wrong number of command-line arguments)
+3
+  problem opening input file
+4
+  bad file content (e.g., unsorted order or empty lines)
+
+
+Availability
+============
+
+:program:`ceph-diff-sorted` is part of Ceph, a massively scalable,
+open-source, distributed storage system.  Please refer to the Ceph
+documentation at http://ceph.com/docs for more information.
+
+See also
+========
+
+:doc:`rgw-orphan-list <rgw-orphan-list>`\(8)