Added way of returning a non-zero exit code to the shell

1 files changed, 45 insertions, 0 deletions

diff --git a/examples/exit_code.py b/examples/exit_code.py
new file mode 100755
index 00000000..e5a896da
--- /dev/null
+++ b/examples/exit_code.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+# coding=utf-8
+"""A simple example demonstrating the following how to emit a non-zero exit code in your cmd2 application.
+"""
+import cmd2
+import sys
+from typing import List
+
+
+class ReplWithExitCode(cmd2.Cmd):
+    """ Example cmd2 application where we can specify an exit code when existing."""
+
+    def __init__(self):
+        super().__init__()
+
+    @cmd2.with_argument_list
+    def do_exit(self, arg_list: List[str]) -> bool:
+        """Exit the application with an optional exit code.
+
+Usage:  exit [exit_code]
+    Where:
+        * exit_code - integer exit code to return to the shell
+"""
+        # If an argument was provided
+        if arg_list:
+            try:
+                self.exit_code = int(arg_list[0])
+            except ValueError:
+                self.perror("{} isn't a valid integer exit code".format(arg_list[0]))
+                self.exit_code = -1
+
+        self._should_quit = True
+        return self._STOP_AND_EXIT
+
+    def postloop(self) -> None:
+        """Hook method executed once when the cmdloop() method is about to return.
+
+        """
+        code = self.exit_code if self.exit_code is not None else 0
+        print('{!r} exiting with code: {}'.format(sys.argv[0], code))
+
+
+if __name__ == '__main__':
+    app = ReplWithExitCode()
+    app.cmdloop()