[apparmor] [patch] ui.py - when using (N)ew, set selected path as default input

[Christian Boltz]

Hello,

Am Mittwoch, 6. August 2014 schrieb Kshitij Gupta:
> On Wed, Aug 6, 2014 at 4:45 AM, Christian Boltz wrote:
> > this patch sets the currently selected path as (editable) default
> > when using "(N)ew" in aa-logprof or aa-genprof.
> > 
> > Credits go to
> > http://stackoverflow.com/questions/2533120/show-default-value-for-ed
> > iting-on-python-input-possible ;-)
> Wow you found it! I recall struggling with curses (a module) for the
> same. Didn't know the solution was so simple. :-)

Once you know "readline" is the keyword, searching is quite easy ;-)

> > Also, some hate goes to the python devs because they changed the
> > meaning of input() between py2 and py3 in a terrible way. (Yes,
> > what py2 input() did was crazy, but it's even more crazy to change
> > its behaviour.)
> A consistent way for input/output is using sys.stdin/sys.stdout but as
> docs state:
> "Settings made using this module affect the behaviour of both the
> interpreter’s interactive prompt and the prompts offered by the
> built-in raw_input() and input() function."
> 
> I guess we have to live with the "sys.version_info[0] >= 3" part for
> this.

Well, we'll survive it ;-)

> > -        sys.stdout.write('\n' + text)
> > -        string = sys.stdin.readline()
> > +        readline.set_startup_hook(lambda:
> > readline.insert_text(default)) +        try:
> > +            if sys.version_info[0] >= 3:
> > +                string = input(text)
> 
> You gobbled a: '\n' before text
> Does it look better without the newline? ;-)

No, it doesn't. Good catch!

Slightly updated patch ('\n' added):

=== modified file 'utils/apparmor/ui.py'
--- utils/apparmor/ui.py        2014-02-24 19:56:28 +0000
+++ utils/apparmor/ui.py        2014-08-06 10:02:59 +0000
@@ -13,6 +13,7 @@
 # ----------------------------------------------------------------------
 import sys
 import re
+import readline
 from apparmor.yasti import yastLog, SendDataToYast, GetDataFromYast
 
 from apparmor.common import readkey, AppArmorException, DebugLogger
@@ -170,8 +171,16 @@
     debug_logger.debug('UI_GetString: %s: %s %s' % (UI_mode, text, default))
     string = default
     if UI_mode == 'text':
-        sys.stdout.write('\n' + text)
-        string = sys.stdin.readline()
+        readline.set_startup_hook(lambda: readline.insert_text(default))
+        try:
+            if sys.version_info[0] >= 3:
+                string = input('\n' + text)
+            else:
+                string = raw_input('\n' + text)
+        except EOFError:
+            string = ''
+        finally:
+            readline.set_startup_hook()
     else:
         SendDataToYast({'type': 'dialog-getstring',
                         'label': text,


> Tested the readline part in py2 and py3, no reason rest of it
> shouldn't work for py2(unfortunately I dont have the libapparmor for
> py2 to test) if it did for py3.

I'll build a new py2 libapparmor package when 2.9 beta2 is out. It's 
just a build switch, but building for both py2 and py3 would make the 
package more interesting[tm].

> Would it be worth the effort to wrap it in a function and move it to
> common.py? Maybe other tools could use it at some point.

I'm looking forward for a saner_than_python_input() function ;-)

Seriously: If we need it again somewhere, we really should split it 
out (including the try/except stuff), but for now I'd keep it inside 
UI_GetString().


Regards,

Christian Boltz
-- 
Nur so aus Interesse: Bist Du in die Gesellschaft "Rettet das
Semikolon!" eingetreten? ;-)
[Jan Trippler in suse-linux  über ein Script von David Haller]