dstat lost color support in ubuntu 10.10

[Maxime Ritter]

Binary package hint: dstat

Usually when I start dstat, there are nice colors displayed.... But on a fresh xubuntu 10.10 installation, instead of colors, I get this error message : Color support is disabled, python-curses is not installed.

root@rakia:~# dstat -al
Color support is disabled, python-curses is not installed.
----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system-- ---load-avg---
usr sys idl wai hiq siq| read writ| recv send| in out | int csw | 1m 5m 15m
  7 2 90 1 0 0| 221k 614k| 0 0 | 0 0 | 992 1560 |0.99 0.66 0.50

And I didn't find any package providing python-curses... Python install bug ? Dstat package ?

[Maxime Ritter (airmax)]

Ok, in fact it is working ; the TERM environment variable was wrongly set up.

So the real bug are :
- why does dstat complain about missing python-curses instead of a wrong TERM environnement ? (not an ubuntu bug)
- why is the default xubuntu terminal application reporting a wrong TERM ? (Bug #659023)

So we can close this bug.

[dag (dag-wieers)]

On Wed, 13 Oct 2010, Maxime Ritter wrote:

> Ok, in fact it is working ; the TERM environment variable was wrongly
> set up.
>
> So the real bug are :
> - why does dstat complain about missing python-curses instead of a wrong TERM environnement ? (not an ubuntu bug)
> - why is the default xubuntu terminal application reporting a wrong TERM ? (Bug #659023)
>
> So we can close this bug.
>
> ** Changed in: dstat (Ubuntu)
> Status: New => Invalid

Quite easy, the block that tests for a functional curses apparently fails
on Ubuntu 10.10. What TERM was set in this case so I can reproduce the
problem and see if another error message makes any sense in this case ?

----
def gettermcolor(color=True):
     "Return whether the system can use colors or not"
     if color and sys.stdout.isatty():
         try:
             import curses
             curses.setupterm()
             if curses.tigetnum('colors') < 0:
                 return False
         except:
             print >>sys.stderr, 'Color support is disabled, python-curses is not installed.'
             return False
     return color
----

If you have a better implementation or any suggestion, feel free to
provide that information rather than pointing in a general direction...

Thanks in advance,
--
-- dag wieers, <email address hidden>, http://dag.wieers.com/ --
[Any errors in spelling, tact or fact are transmission errors]

[Maxime Ritter (airmax)]

dag wrote:
> Quite easy, the block that tests for a functional curses apparently fails
> on Ubuntu 10.10. What TERM was set in this case so I can reproduce the
> problem and see if another error message makes any sense in this case ?

TERM=dumb

It's very easy to reproduce : take a Xubuntu i386 10.10 CD, and install it with an unplugged internet connection (or without the package updates, as the fix for Bug #621927 has been released, but didn't catch my mirror). Reboot, run the xfce terminal (default terminal in xubuntu), apt-get install dstat, then run dstat....

>
> ----
> def gettermcolor(color=True):
> "Return whether the system can use colors or not"
> if color and sys.stdout.isatty():
> try:
> import curses
> curses.setupterm()
> if curses.tigetnum('colors') < 0:
> return False
> except:
> print >>sys.stderr, 'Color support is disabled, python-curses is not installed.'
> return False
> return color
> ----
>
> If you have a better implementation or any suggestion, feel free to
> provide that information rather than pointing in a general direction...

I don't know Python, but I can some suggest 2 fixes :

1. you can change the message to "Color support is disabled, python-curses is not installed, not working, or TERM $env{'TERM'} not recognized".

2. Something like that (like that, as I said, I don't the Python langage) :

def gettermcolor(color=True):
     "Return whether the system can use colors or not"
     if color and sys.stdout.isatty():
         try:
             import curses
         except:
             print >>sys.stderr, 'Color support is disabled, python-curses is not installed.'
             return False
 try:
             curses.setupterm()
             if curses.tigetnum('colors') < 0:
                 return False
         except:
             print >>sys.stderr, 'Color support is disabled; TERM=$ENV{'TERM'} not recognized, or python-curses is not working.'
             return False
     return color

[dag (dag-wieers)]

On Thu, 14 Oct 2010, Maxime Ritter wrote:

> dag wrote:
>> Quite easy, the block that tests for a functional curses apparently fails
>> on Ubuntu 10.10. What TERM was set in this case so I can reproduce the
>> problem and see if another error message makes any sense in this case ?
>
> TERM=dumb
>
> It's very easy to reproduce : take a Xubuntu i386 10.10 CD, and install
> it with an unplugged internet connection (or without the package
> updates, as the fix for Bug #621927 has been released, but didn't catch
> my mirror). Reboot, run the xfce terminal (default terminal in xubuntu),
> apt-get install dstat, then run dstat....

Apparently the wrong TERM is not the cause for this. Trying to reproduce
this on my CentOS system I get:

[dag@moria dstat]$ TERM=dumb ./dstat -ta
----system---- ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
      time |usr sys idl wai hiq siq| read writ| recv send| in out | int csw
14-10 09:57:45| 6 1 92 1 0 0| 29k 50k| 0 0 |4924B 5696B|2408 7228
14-10 09:57:46| 2 0 98 0 0 0| 0 0 | 262B 112B| 0 0 | 324 685

So the wrong TERM is not the cause here. Could you remove the try/except
statement around that block and send me the exception you get ?

Also, what version of Dstat is this ?

>> ----
>> def gettermcolor(color=True):
>> "Return whether the system can use colors or not"
>> if color and sys.stdout.isatty():
>> try:
>> import curses
>> curses.setupterm()
>> if curses.tigetnum('colors') < 0:
>> return False
>> except:
>> print >>sys.stderr, 'Color support is disabled, python-curses is not installed.'
>> return False
>> return color
>> ----
>>
>> If you have a better implementation or any suggestion, feel free to
>> provide that information rather than pointing in a general direction...
>
> I don't know Python, but I can some suggest 2 fixes :
>
> 1. you can change the message to "Color support is disabled, python-
> curses is not installed, not working, or TERM $env{'TERM'} not
> recognized".
>
> 2. Something like that (like that, as I said, I don't the Python
> langage) :
>
> def gettermcolor(color=True):
> "Return whether the system can use colors or not"
> if color and sys.stdout.isatty():
> try:
> import curses
> except:
> print >>sys.stderr, 'Color support is disabled, python-curses is not installed.'
> return False
> try:
> curses.setupterm()
> if curses.tigetnum('colors') < 0:
> return False
> except:
> print >>sys.stderr, 'Color support is disabled; TERM=$ENV{'TERM'} not recognized, or python-curses is not working.'
> return False
> return color

Yes, that's what I would expect, although without a proven root-cause or
reproducing the problem I prefer not to change it yet.

--
-- dag wieers, <email address hidden>, http://dag.wieers.com/ --
[Any errors in spelling, tact or fact are transmission errors]

[dag (dag-wieers)]

On Thu, 14 Oct 2010, dag wrote:

> On Thu, 14 Oct 2010, Maxime Ritter wrote:
>
>> dag wrote:
>>> Quite easy, the block that tests for a functional curses apparently fails
>>> on Ubuntu 10.10. What TERM was set in this case so I can reproduce the
>>> problem and see if another error message makes any sense in this case ?
>>
>> TERM=dumb
>>
>> It's very easy to reproduce : take a Xubuntu i386 10.10 CD, and install
>> it with an unplugged internet connection (or without the package
>> updates, as the fix for Bug #621927 has been released, but didn't catch
>> my mirror). Reboot, run the xfce terminal (default terminal in xubuntu),
>> apt-get install dstat, then run dstat....
>
> Apparently the wrong TERM is not the cause for this. Trying to reproduce
> this on my CentOS system I get:
>
> [dag@moria dstat]$ TERM=dumb ./dstat -ta
> ----system---- ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
> time |usr sys idl wai hiq siq| read writ| recv send| in out | int csw
> 14-10 09:57:45| 6 1 92 1 0 0| 29k 50k| 0 0 |4924B 5696B|2408 7228
> 14-10 09:57:46| 2 0 98 0 0 0| 0 0 | 262B 112B| 0 0 | 324 685
>
> So the wrong TERM is not the cause here. Could you remove the try/except
> statement around that block and send me the exception you get ?

Ok, I had some time to look at this and on CentOS 'dumb' is in fact a real
termcap entry that does not support colors. But if I instead use something
fake, I get this:

[dag@moria dstat]$ TERM=dag dstat -ta
Color support is disabled, python-curses is not installed.
----system---- ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
      time |usr sys idl wai hiq siq| read writ| recv send| in out | int csw
14-10 19:39:25| 2 0 98 0 0 0| 77k 70k| 0 0 | 0 0 | 318 637
14-10 19:39:26| 1 1 99 0 0 0| 0 0 | 0 0 | 0 0 | 547 1389

So I have now fixed this to display:

[dag@moria dstat]$ TERM=dag ./dstat -ta
Color support is disabled as terminal (TERM=dag) does not support colors.
----system---- ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
      time |usr sys idl wai hiq siq| read writ| recv send| in out | int csw
14-10 19:40:06| 2 0 98 0 0 0| 77k 70k| 0 0 | 0 0 | 318 638
14-10 19:40:07| 1 1 99 0 0 0| 0 16k| 0 0 | 0 0 | 515 1210

The fix was quite simple:

----
def gettermcolor(color=True):
     "Return whether the system can use colors or not"
     if color and sys.stdout.isatty():
         try:
             import curses
             curses.setupterm()
             if curses.tigetnum('colors') < 0:
                 return False
         except ImportError:
             print >>sys.stderr, 'Color support is disabled as python-curses is not installed.'
             return False
         except:
             print >>sys.stderr, 'Color support is disabled as terminal (TERM=%s) does not support colors.' % os.getenv('TERM')
             return False
     return color
----

Thanks for reporting !
--
-- dag wieers, <email address hidden>, http://dag.wieers.com/ --
[Any errors...