Added exit codes for HTTP 3xx, 4xx, 5xx (3, 4, 5).

Also added `--ignore-http-status` to ensure 0 exit status.

HTTP 3xx result in 0 exit status when `--allow-redirects` is set.

6 files changed, 123 insertions, 13 deletions

diff --git a/README.rst b/README.rst
index 9505e97f..4068ebca 100644
--- a/README.rst
+++ b/README.rst
@@ -170,9 +170,9 @@ See ``http -h`` for more details::
     usage: http [-h] [--version] [--json | --form] [--traceback]
                 [--pretty | --ugly]
                 [--print OUTPUT_OPTIONS | --verbose | --headers | --body]
-                [--style STYLE] [--auth AUTH] [--auth-type {basic,digest}]
-                [--verify VERIFY] [--proxy PROXY] [--allow-redirects]
-                [--timeout TIMEOUT]
+                [--style STYLE] [--ignore-http-status] [--auth AUTH]
+                [--auth-type {basic,digest}] [--verify VERIFY] [--proxy PROXY]
+                [--allow-redirects] [--timeout TIMEOUT]
                 [METHOD] URL [ITEM [ITEM ...]]
 
     HTTPie - cURL for humans. <http://httpie.org>
@@ -235,6 +235,14 @@ See ``http -h`` for more details::
                             make sure that the $TERM environment variable is set
                             to "xterm-256color" or similar (e.g., via `export TERM
                             =xterm-256color' in your ~/.bashrc).
+      --ignore-http-status  This flag tells HTTP to ignore the HTTP status code
+                            and exit with 0. By default, HTTPie exits with 0 only
+                            if no errors occur and the request is successful. When
+                            the server replies with a 4xx (Client Error) or 5xx
+                            (Server Error) status code, HTTPie exits with 4 or 5
+                            respectively. If the response is 3xx (Redirect) and
+                            --allow-redirects isn't set, then the exit status is
+                            3.
       --auth AUTH, -a AUTH  username:password. If only the username is provided
                             (-a username), HTTPie will prompt for the password.
       --auth-type {basic,digest}
@@ -287,6 +295,7 @@ Changelog
 ---------
 
 * `0.2.6dev <https://github.com/jkbr/httpie/compare/0.2.5...master>`_
+    * Added exit status codes for HTTP 3xx, 4xx and 5xx (3, 4, 5).
     * If the output is piped to another program or redirected to a file,
       the new default behaviour is to only print the response body.
       (It can still be overriden via the ``--print`` flag.)
diff --git a/httpie/__main__.py b/httpie/__main__.py
index 83a66d6c..cbda8afd 100644
--- a/httpie/__main__.py
+++ b/httpie/__main__.py
@@ -3,8 +3,9 @@
 The main entry point. Invoke as `http' or `python -m httpie'.
 
 """
+import sys
 from .core import main
 
 
 if __name__ == '__main__':
-    main()
+    sys.exit(main())
diff --git a/httpie/cli.py b/httpie/cli.py
index fa166b63..5c1b9610 100644
--- a/httpie/cli.py
+++ b/httpie/cli.py
@@ -125,6 +125,21 @@ parser.add_argument(
     ''') % ', '.join(sorted(AVAILABLE_STYLES))
 )
 
+parser.add_argument(
+    '--ignore-http-status', default=False, action='store_true',
+    help=_('''
+        This flag tells HTTP to ignore the HTTP status code
+        and exit with 0.
+
+        By default, HTTPie exits with 0 only if no errors occur
+        and the request is successful. When the server
+        replies with a 4xx (Client Error) or 5xx (Server Error)
+        status code, HTTPie exits with 4 or 5 respectively.
+        If the response is 3xx (Redirect) and --allow-redirects
+        isn't set, then the exit status is 3.
+    ''')
+)
+
 # ``requests.request`` keyword arguments.
 parser.add_argument(
     '--auth', '-a', type=cliparse.AuthCredentialsType(cliparse.SEP_COMMON),
diff --git a/httpie/core.py b/httpie/core.py
index f0617e31..52711834 100644
--- a/httpie/core.py
+++ b/httpie/core.py
@@ -114,10 +114,39 @@ def get_output(args, env, response):
     return ''.join(buf)
 
 
+def get_exist_status(code, allow_redirects=False):
+    """
+    Translate HTTP status code to exit status.
+
+    """
+    if 300 <= code <= 399 and not allow_redirects:
+        # Redirect
+        return 3
+    elif 400 <= code <= 499:
+        # Client Error
+        return 4
+    elif 500 <= code <= 599:
+        # Server Error
+        return 5
+    else:
+        return 0
+
+
 def main(args=sys.argv[1:], env=Environment()):
+    """
+    Run the main program and write the output to ``env.stdout``.
+
+    Return exit status.
+
+    """
     args = cli.parser.parse_args(args=args, env=env)
     response = get_response(args)
     output = get_output(args, env, response)
     output_bytes = output.encode('utf8')
     f = getattr(env.stdout, 'buffer', env.stdout)
     f.write(output_bytes)
+    if args.ignore_http_status:
+        return 0
+    else:
+        return get_exist_status(
+            response.status_code, args.allow_redirects)
diff --git a/httpie/output.py b/httpie/output.py
index 1545e0af..226a3b0d 100644
--- a/httpie/output.py
+++ b/httpie/output.py
@@ -2,7 +2,6 @@
 Colorizing of HTTP messages and content processing.
 
 """
-import os
 import re
 import json
 import pygments
diff --git a/tests/tests.py b/tests/tests.py
index 0c89fd6d..4d92b690 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -21,8 +21,7 @@ import json
 import tempfile
 import unittest
 import argparse
-from requests import Response
-from requests.compat import is_py26, is_py3
+from requests.compat import is_py26, is_py3, str
 
 
 #################################################################
@@ -51,28 +50,40 @@ def httpbin(path):
     return HTTPBIN_URL + path
 
 
+class Response(str):
+    """
+    A unicode subclass holding the output of `main()` and the exit status.
+
+    """
+    exit_status = None
+
+
 def http(*args, **kwargs):
     """
-    Invoke `httpie.__main__.main` with `args` and `kwargs`,
+    Invoke `httpie.core.main()` with `args` and `kwargs`,
     and return a unicode response.
 
     """
 
     if 'env' not in kwargs:
-        # Ensure that we have terminal by default
-        # (needed for Travis).
+        # Ensure that we have terminal by default (needed for Travis).
         kwargs['env'] = Environment(
             colors=0,
             stdin_isatty=True,
             stdout_isatty=True,
         )
 
-
     stdout = kwargs['env'].stdout = tempfile.TemporaryFile()
-    main(args=args, **kwargs)
+
+    exit_status = main(args=args, **kwargs)
+
     stdout.seek(0)
-    response = stdout.read().decode('utf8')
+
+    response = Response(stdout.read().decode('utf8'))
+    response.exit_status = exit_status
+
     stdout.close()
+
     return response
 
 
@@ -494,6 +505,52 @@ class AuthTest(BaseTestCase):
         self.assertIn('"user": "user"', r)
 
 
+class ExitStatusTest(BaseTestCase):
+
+    def test_3xx_exits_3(self):
+        r = http(
+            'GET',
+            httpbin('/status/301')
+        )
+        self.assertIn('HTTP/1.1 301', r)
+        self.assertEqual(r.exit_status, 3)
+
+    def test_3xx_redirects_allowed_exits_0(self):
+        r = http(
+            '--allow-redirects',
+            'GET',
+            httpbin('/status/301')
+        )
+        # The redirect will be followed so 200 is expected.
+        self.assertIn('HTTP/1.1 200 OK', r)
+        self.assertEqual(r.exit_status, 0)
+
+    def test_4xx_exits_4(self):
+        r = http(
+            'GET',
+            httpbin('/status/401')
+        )
+        self.assertIn('HTTP/1.1 401', r)
+        self.assertEqual(r.exit_status, 4)
+
+    def test_5xx_exits_5(self):
+        r = http(
+            'GET',
+            httpbin('/status/500')
+        )
+        self.assertIn('HTTP/1.1 500', r)
+        self.assertEqual(r.exit_status, 5)
+
+    def test_ignore_http_status_exits_0(self):
+        r = http(
+            '--ignore-http-status',
+            'GET',
+            httpbin('/status/500')
+        )
+        self.assertIn('HTTP/1.1 500', r)
+        self.assertEqual(r.exit_status, 0)
+
+
 #################################################################
 # CLI argument parsing related tests.
 #################################################################