* confusion about expansion
@ 2014-03-12 14:00 Lars Huttar
2014-03-12 14:05 ` Wolfgang Schuster
0 siblings, 1 reply; 7+ messages in thread
From: Lars Huttar @ 2014-03-12 14:00 UTC (permalink / raw)
To: mailing list for ConTeXt users
Hello,
I've got a running page head like this in my document:
\def\CurrentUser{\cldcontext{os.resultof"whoami"}}
\def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
\contextversion }
and later:
\setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
But when I run this, I get a UCS error that seems to indicate that the
*result* of \CurrentUser ("waxhaw\huttar") is getting parsed as a
command sequence.
Here's the error:
! Undefined control sequence.
1 >> % see ConTeXt wiki http://wiki.contextgarden.net/Imposition#Cut_marks
2
3 %% TODO: make sure this doesn't reevaluate every time
4 %% the command sequence is used!
5 \define\CurrentUser{\cldcontext{os.resultof"whoami"}}
6
7 \def\Markname { Compiled \date by \CurrentUser \LUATEX
+\ConTeXt\ \conte
xtversion. SVN }
...
l.1 waxhaw\huttar
\cldcontext #1x-\directlua {context(#1)}
\Markname #- Compiled \date by \CurrentUser
\LUATEX +\ConTeXt \
\contextvers...
l.24 ...t=lefttop,x=3cm,y=-1.5\lineheight]{\Markname
}
How can I change the definition of \CurrentUser, or \Markname, to output
the result of \CurrentUser as-is, instead of parsing the result?
I tried (somewhat blindly) changing \def to \define, but it didn't make
any difference.
At the same time, I want to make sure that the processor won't be making
an OS system call to "whoami" every time \CurrentUser is evaluated: I
want it to happen only once, when \CurrentUser is defined.
Here is my complete working example:
\def\CurrentUser{\cldcontext{os.resultof"whoami"}}
\def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
\contextversion. }
\setuplayout[location=middle,marking=on]
\definelayer[cropmark][state=repeat,width=\paperwidth,height=\paperheight]
\setupbackgrounds[page][background=cropmark]
\setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
\starttext
Foo
\stoptext
Thanks for any help.
Lars
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: confusion about expansion
2014-03-12 14:00 confusion about expansion Lars Huttar
@ 2014-03-12 14:05 ` Wolfgang Schuster
2014-03-12 14:12 ` Lars Huttar
0 siblings, 1 reply; 7+ messages in thread
From: Wolfgang Schuster @ 2014-03-12 14:05 UTC (permalink / raw)
To: mailing list for ConTeXt users
Am 12.03.2014 um 15:00 schrieb Lars Huttar <lars_huttar@sil.org>:
> Hello,
> I've got a running page head like this in my document:
>
> \def\CurrentUser{\cldcontext{os.resultof"whoami"}}
>
> \def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
> \contextversion }
>
> and later:
>
> \setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
>
> But when I run this, I get a UCS error that seems to indicate that the
> *result* of \CurrentUser ("waxhaw\huttar") is getting parsed as a
> command sequence.
When you want to pass a backslash to Lua you have to use \letterbackslash.
Wolfgang
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: confusion about expansion
2014-03-12 14:05 ` Wolfgang Schuster
@ 2014-03-12 14:12 ` Lars Huttar
2014-03-12 14:21 ` Wolfgang Schuster
0 siblings, 1 reply; 7+ messages in thread
From: Lars Huttar @ 2014-03-12 14:12 UTC (permalink / raw)
To: mailing list for ConTeXt users
On 3/12/2014 10:05 AM, Wolfgang Schuster wrote:
> Am 12.03.2014 um 15:00 schrieb Lars Huttar <lars_huttar@sil.org>:
>
>> Hello,
>> I've got a running page head like this in my document:
>>
>> \def\CurrentUser{\cldcontext{os.resultof"whoami"}}
>>
>> \def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
>> \contextversion }
>>
>> and later:
>>
>> \setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
>>
>> But when I run this, I get a UCS error that seems to indicate that the
>> *result* of \CurrentUser ("waxhaw\huttar") is getting parsed as a
>> command sequence.
> When you want to pass a backslash to Lua you have to use \letterbackslash.
>
Thanks... can you give me an example of what that would look like?
I don't think I want to pass a backslash to Lua, so I'm not sure how to
apply what you're saying. Or are you using "Lua" here in the sense of
LuaTeX?
A backslash appears in the output of os.resultof"whoami"; do I need to
perform some processing on that output in order to escape backslashes?
Lars
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: confusion about expansion
2014-03-12 14:12 ` Lars Huttar
@ 2014-03-12 14:21 ` Wolfgang Schuster
2014-03-12 14:51 ` Lars Huttar
0 siblings, 1 reply; 7+ messages in thread
From: Wolfgang Schuster @ 2014-03-12 14:21 UTC (permalink / raw)
To: mailing list for ConTeXt users
[-- Attachment #1.1: Type: text/plain, Size: 1647 bytes --]
Am 12.03.2014 um 15:12 schrieb Lars Huttar <lars_huttar@sil.org>:
> On 3/12/2014 10:05 AM, Wolfgang Schuster wrote:
>> Am 12.03.2014 um 15:00 schrieb Lars Huttar <lars_huttar@sil.org>:
>>
>>> Hello,
>>> I've got a running page head like this in my document:
>>>
>>> \def\CurrentUser{\cldcontext{os.resultof"whoami"}}
>>>
>>> \def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
>>> \contextversion }
>>>
>>> and later:
>>>
>>> \setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
>>>
>>> But when I run this, I get a UCS error that seems to indicate that the
>>> *result* of \CurrentUser ("waxhaw\huttar") is getting parsed as a
>>> command sequence.
>> When you want to pass a backslash to Lua you have to use \letterbackslash.
>>
>
> Thanks... can you give me an example of what that would look like?
> I don't think I want to pass a backslash to Lua, so I'm not sure how to
> apply what you're saying. Or are you using "Lua" here in the sense of
> LuaTeX?
>
> A backslash appears in the output of os.resultof"whoami"; do I need to
> perform some processing on that output in order to escape backslashes?
Try this:
\def\CurrentUser{\cldcontext{os.resultof"whoami"}}
\def\Markname{Compiled \date by \detokenize\expandafter{\CurrentUser} \LUATEX +\ConTeXt\ \contextversion.}
\setuplayout[location=middle,marking=on]
\definelayer[cropmark][state=repeat,width=\paperwidth,height=\paperheight]
\setupbackgrounds[page][background=cropmark]
\setlayer[cropmark][preset=lefttop,x=3cm,y=1.5\lineheight]{\Markname}
\starttext
Foo
\stoptext
Wolfgang
[-- Attachment #1.2: Type: text/html, Size: 2631 bytes --]
[-- Attachment #2: Type: text/plain, Size: 485 bytes --]
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: confusion about expansion
2014-03-12 14:21 ` Wolfgang Schuster
@ 2014-03-12 14:51 ` Lars Huttar
2014-03-12 15:06 ` Wolfgang Schuster
0 siblings, 1 reply; 7+ messages in thread
From: Lars Huttar @ 2014-03-12 14:51 UTC (permalink / raw)
To: mailing list for ConTeXt users
On 3/12/2014 10:21 AM, Wolfgang Schuster wrote:
>
> Am 12.03.2014 um 15:12 schrieb Lars Huttar <lars_huttar@sil.org
> <mailto:lars_huttar@sil.org>>:
>
>> On 3/12/2014 10:05 AM, Wolfgang Schuster wrote:
>>> Am 12.03.2014 um 15:00 schrieb Lars Huttar <lars_huttar@sil.org
>>> <mailto:lars_huttar@sil.org>>:
>>>
>>>> Hello,
>>>> I've got a running page head like this in my document:
>>>>
>>>> \def\CurrentUser{\cldcontext{os.resultof"whoami"}}
>>>>
>>>> \def\Markname { Compiled \date by \CurrentUser \LUATEX +\ConTeXt\
>>>> \contextversion }
>>>>
>>>> and later:
>>>>
>>>> \setlayer[cropmark][preset=lefttop,x=3cm,y=-1.5\lineheight]{\Markname}
>>>>
>>>> But when I run this, I get a UCS error that seems to indicate that the
>>>> *result* of \CurrentUser ("waxhaw\huttar") is getting parsed as a
>>>> command sequence.
>>> When you want to pass a backslash to Lua you have to use
>>> \letterbackslash.
>>>
>>
>> Thanks... can you give me an example of what that would look like?
>> I don't think I want to pass a backslash to Lua, so I'm not sure how to
>> apply what you're saying. Or are you using "Lua" here in the sense of
>> LuaTeX?
>>
>> A backslash appears in the output of os.resultof"whoami"; do I need to
>> perform some processing on that output in order to escape backslashes?
>
> Try this:
>
> \def\CurrentUser{\cldcontext{os.resultof"whoami"}}
>
> \def\Markname{Compiled \date by \detokenize\expandafter{\CurrentUser}
> \LUATEX +\ConTeXt\ \contextversion.}
>
> \setuplayout[location=middle,marking=on]
>
> \definelayer[cropmark][state=repeat,width=\paperwidth,height=\paperheight]
>
> \setupbackgrounds[page][background=cropmark]
>
> \setlayer[cropmark][preset=lefttop,x=3cm,y=1.5\lineheight]{\Markname}
>
> \starttext
>
> Foo
>
> \stoptext
>
>
Thanks again...
This gets rid of the error, but it seems to prevent any expansion of the
content of \CurrentUser, because the page head now literally looks like
this:
Compiled March 12, 2014 by \cldcontext {os.resultof"whoami"}.
LuaTEX+ConTEXt...
Lars
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2014-03-12 15:45 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-03-12 14:00 confusion about expansion Lars Huttar
2014-03-12 14:05 ` Wolfgang Schuster
2014-03-12 14:12 ` Lars Huttar
2014-03-12 14:21 ` Wolfgang Schuster
2014-03-12 14:51 ` Lars Huttar
2014-03-12 15:06 ` Wolfgang Schuster
2014-03-12 15:45 ` Lars Huttar
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).