contentlocation, examinekey, lookupkey: Added --batch mode option.

doc/git-annex-contentlocation.mdwn

@@ -16,6 +16,17 @@ Note that in direct mode, the file will typically be in the git work
 tree, and while its content should correspond to the key, the file
 could become modified at any time after git-annex checks it.
 
+# OPTIONS
+
+* `--batch`
+
+  Enable batch mode, in which a line containing the key is read from
+  stdin, the filename to its content is output to stdout (with a trailing
+  newline), and repeat.
+
+  Note that if a key's content is not present, an empty line is output to
+  stdout instead.
+
 # SEE ALSO
 
 [[git-annex]](1)

doc/git-annex-examinekey.mdwn

@@ -33,6 +33,11 @@ that can be determined purely by looking at the key.
   Enable JSON output. This is intended to be parsed by programs that use
   git-annex. Each line of output is a JSON object.
 
+* `--batch`
+
+  Enable batch mode, in which a line containing a key is read from stdin,
+  the information about it is output to stdout, and repeat.
+
 # EXAMPLES
 
 The location a key's value is stored (in indirect mode)

doc/git-annex-lookupkey.mdwn

@@ -13,6 +13,16 @@ index. The key is output to stdout. If there is no key (because
 the file is not present in the index, or is not a git-annex managed file),
 nothing is output, and it exits nonzero.
 
+# OPTIONS
+
+* `--batch`
+
+  Enable batch mode, in which a line containing the filename is read from
+  stdin, the key is output to stdout (with a trailing newline), and repeat.
+
+  Note that is there is no key corresponding to the file, an empty line is
+  output to stdout instead.
+
 # SEE ALSO
 
 [[git-annex]](1)