support options --json and --quiet

README.md

@@ -36,6 +36,9 @@ environment variable `XDG_DATA_DIRS`.
 
 - `-v`, `--verbose`: Print directives in found .desktop files.
 
+- `-j`, `--json`: Print .desktop files found and directives to display
+  as JSON data structure (see also EXAMPLES below).
+
 - `-d STRING`, `--show-directive STRING`: Instead of printing all directives
   when searching in verbose mode, print only the directive given by `STRING`
   (e.g. "Name").  Option can be repeated to print multiple directives.
@@ -47,17 +50,37 @@ environment variable `XDG_DATA_DIRS`.
 ## RETURN VALUES
 
 The command returns 0 if .desktop files were found that match the specified
-criteria, 1 on usage error and 2 if no matching .desktop files were found.
+criteria, 1 if no matching .desktop files were found and 127 on usage error.
 
-## EXAMPLE
+## EXAMPLES
 
 Search for the string "firefox" in all .desktop files found in the path
 specified by `XDG_DATA_DIRS`. To match, the string "firefox" must be contained
 in either the "Exec" or the "Comment" directive. List the matching files, also
 show the "Exec" and "TryExec" directives in each found file.
 
+`xdg-desktop-search -s Exec -s Comment -v -d Exec -d TryExec firefox`
+
+Search for .desktop files containing GVim in their "Name" directive and
+determine the value of the "Exec" directive in the files found.  Display
+results as JSON data structure:
+
+`xdg-desktop-search -j -d Exec -s Name GVim`
+
+Result:
+
 ```
-xdg-desktop-search -s Exec -s Comment -v -d Exec -d TryExec firefox
+[
+  {
+    "desktop": "/usr/share/applications/gvim.desktop",
+    "results": [
+      {
+        "directive": "Exec",
+        "value": "gvim -f %F"
+      }
+    ]
+  }
+]
 ```
 
 ## AUTHOR AND COPYRIGHT
@@ -70,7 +93,7 @@ xdg-desktop-search is distributed under the terms and conditions of the MIT
 license <https://opensource.org/license/mit>.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the “Software”), to deal in
+this software and associated documentation files (the "Software"), to deal in
 the Software without restriction, including without limitation the rights to
 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 of the Software, and to permit persons to whom the Software is furnished to do
@@ -79,7 +102,7 @@ so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 
-THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER