Add --output-to-tab flag for :spawn.

This puts the exit status, stdout, and stderr in a new tab.

doc/help/commands.asciidoc

@@ -1148,7 +1148,7 @@ Set a mark at the current scroll position in the current tab.
 
 [[spawn]]
 === spawn
-Syntax: +:spawn [*--userscript*] [*--verbose*] [*--detach*] 'cmdline'+
+Syntax: +:spawn [*--userscript*] [*--verbose*] [*--output-to-tab*] [*--detach*] 'cmdline'+
 
 Spawn a command in a shell.
 
@@ -1163,6 +1163,7 @@ Spawn a command in a shell.
  - `/usr/share/qutebrowser/userscripts`
 
 * +*-v*+, +*--verbose*+: Show notifications when the command started/exited.
+* +*-v*+, +*--output-to-tab*+: Show stderr, stdout, and exit status in a new tab.
 * +*-d*+, +*--detach*+: Whether the command should be detached from qutebrowser.
 
 ==== note

qutebrowser/browser/commands.py

@@ -1177,7 +1177,8 @@ class CommandDispatcher:
 
     @cmdutils.register(instance='command-dispatcher', scope='window',
                        maxsplit=0, no_replace_variables=True)
-    def spawn(self, cmdline, userscript=False, verbose=False, detach=False):
+    def spawn(self, cmdline, userscript=False, verbose=False,
+            output_to_tab=False, detach=False):
         """Spawn a command in a shell.
 
         Args:
@@ -1208,7 +1209,8 @@ class CommandDispatcher:
         else:
             cmd = os.path.expanduser(cmd)
             proc = guiprocess.GUIProcess(what='command', verbose=verbose,
-                                         parent=self._tabbed_browser)
+                                         parent=self._tabbed_browser,
+                                         output_to_tab=output_to_tab)
             if detach:
                 proc.start_detached(cmd, args)
             else:

qutebrowser/browser/qutescheme.py

@@ -42,6 +42,7 @@ from qutebrowser.misc import objects
 
 
 pyeval_output = ":pyeval was never called"
+spawn_output = ":spawn was never called"
 
 
 _HANDLERS = {}
@@ -268,6 +269,13 @@ def qute_pyeval(_url):
     return 'text/html', html
 
 
+@add_handler('spawn_output')
+def qute_spawn_output(_url):
+    """Handler for qute://spawn_output."""
+    html = jinja.render('pre.html', title='spawn output', content=spawn_output)
+    return 'text/html', html
+
+
 @add_handler('version')
 @add_handler('verizon')
 def qute_version(_url):

qutebrowser/misc/guiprocess.py

@@ -22,9 +22,11 @@
 import shlex
 
 from PyQt5.QtCore import (pyqtSlot, pyqtSignal, QObject, QProcess,
-                          QProcessEnvironment)
+                          QProcessEnvironment, QUrl)
 
-from qutebrowser.utils import message, log
+from qutebrowser.utils import message, log, objreg
+
+from qutebrowser.browser import qutescheme
 
 # A mapping of QProcess::ErrorCode's to human-readable strings.
 
@@ -62,10 +64,11 @@ class GUIProcess(QObject):
     started = pyqtSignal()
 
     def __init__(self, what, *, verbose=False, additional_env=None,
-                 parent=None):
+                 parent=None, output_to_tab=False):
         super().__init__(parent)
         self._what = what
         self.verbose = verbose
+        self.output_to_tab = output_to_tab
         self._started = False
         self.cmd = None
         self.args = None
@@ -96,6 +99,30 @@ class GUIProcess(QObject):
         self._started = False
         log.procs.debug("Process finished with code {}, status {}.".format(
             code, status))
+
+        stdout = None
+        stderr = None
+
+        if self.output_to_tab:
+            stderr = bytes(self._proc.readAllStandardError()).decode('utf-8')
+            stdout = bytes(self._proc.readAllStandardOutput()).decode('utf-8')
+
+            spawn_log = ""
+
+            spawn_log += "Process finished with code {},status {}.".format(
+                code, status)
+
+            if stdout:
+                spawn_log += "\nProcess stdout:\n" + stdout.strip()
+            if stderr:
+                spawn_log += "\nProcess stderr:\n" + stderr.strip()
+
+            qutescheme.spawn_output = spawn_log
+
+            tabbed_browser = objreg.get('tabbed-browser', scope='window',
+                                    window='last-focused')
+            tabbed_browser.openurl(QUrl('qute://spawn_output'), newtab=True)
+
         if status == QProcess.CrashExit:
             message.error("{} crashed!".format(self._what.capitalize()))
         elif status == QProcess.NormalExit and code == 0: