Re: annoying symbols in logfiles

[Joerg Arndt <arndt@jjj.de>]

I suggest to use isatty() in the pari code to detect whether the
output is actually a terminal.  If not a terminal, then the escape
sequences should be dropped.  This is the behavior of many programs
offering colorized output, e.g., non-ancient versions of grep.

Best regards,   Joerg Arndt



* Karim Belabas <Karim.Belabas@math.u-bordeaux.fr> [Jun 11. 2016 08:38]:
> * Vasily Golyshev [2016-06-10 18:50]:
> > here's how Pari logs the session in a log file
> > on my fresh install from .deb:
> > 
> >  GP/PARI CALCULATOR Version 2.5.5 (released)
> >           amd64 running linux (x86-64/GMP-5.1.2 kernel) 64-bit version
> >        compiled: Sep 30 2013, gcc-4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu4)
> >      (readline v6.3 enabled [was v6.2 in Configure], extended help enabled)
> > 
> > 
> > [0;33m ?   [0;34m fi=zetakinit(y^2+3);
> 
> These are ANSI escape sequences used to change font colour in gp's
> terminal (and which some editors or plain 'cat' are able to render when
> viewing the logfile). Color 3, then ?, then color 4 [ by default, this
> should print a yellowish question mark, then the rest of the line in
> blue ].
> 
> >   [0;33m ?   [0;34m ze=zetak(fi,3)/zeta(3)
> > %77 = 0.88402381175007985674305791687101180775
> > 
> > How can one get rid of the extra symbols? Should I recompile using
> > Configure/Make?
> 
> 1) This was fixed in release 2.7.0 (04/2013), any later version should be fine
> (current stable version is 2.7.5).
> 
> 2) Something that will work in all versions is to set the 'colors'
> default so that it leaves "prompt" and "input line" alone, see ??colors
> [ I use black for these two ]
> 
> My advice is to upgrade :-)
> 
> Cheers,
> 
>     K.B.
> --
> Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
> Universite de Bordeaux         Fax: (+33) (0)5 40 00 69 50
> 351, cours de la Liberation    http://www.math.u-bordeaux.fr/~kbelabas/
> F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
> `