[GRASS-dev] [GRASS GIS] #2156: Parser does not honor the dash (-) means stdout convention

[GRASS GIS]

#2156: Parser does not honor the dash (-) means stdout convention
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 Reporter:  wenzeslaus                    |       Owner:  grass-dev@…              
     Type:  defect                        |      Status:  new                      
 Priority:  trivial                       |   Milestone:  7.0.0                    
Component:  Parser                        |     Version:  svn-trunk                
 Keywords:  stdout, r.colors.out, m.proj  |    Platform:  Unspecified              
      Cpu:  Unspecified                   |  
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 I cannot run `r.colors.out` with `rules=-` when I have file named `-` in
 the current directory:

 {{{
 #!sh
 # create a file named -
 # touch - does not work for me
 $ touch testfile && mv testfile -

 # try to output rules
 $ r.colors.out map=elevation rules=-
 ERROR: option <rules>: <-> exists.

 # now remove the file named - and try again
 $ rm -
 $ r.colors.out map=elevation at PERMANENT rules=-
 55.5788 0:191:191
 75.729 0:255:0
 95.8792 255:255:0
 116.029 255:127:0
 136.18 191:127:63
 156.33 20:20:20
 nv 255:255:255
 default 255:255:255
 }}}

 Well, I'm not sure what should be the right behavior of the parser, this
 current one is bit confusing, so I think that it should be at least
 reported. What puzzles me, is how the `-` file actually appeared in the
 directory. It already happened to me at least two times (in past moths)
 that `r.colors.out` (or something I used together with it), created the
 `-` file. I used some other way and haven't reported the issue at that
 time, now I'm not able to reproduce it (from command line and GUI).
 According to the short note I made at that time it seems that it was
 pretty clear that `r.colors.out` is the cause.

 Nevertheless, the behavior of parser is confusing when the module supports
 "`-` (dash, minus) means standard output" convention and current directory
 contains file named `-`. Affected modules are at least G7:r.colors.out and
 G7:m.proj. Probably the number of modules supporting `-` as a placeholder
 for stdout, the preferred interpretation of `-` and safety are the factors
 influencing how parser behave.

 To be complete, for standard input, no support is needed in parser, test
 for G7:r.color:

 {{{
 #!sh
 $ touch testfile && mv testfile -
 $ r.colors map=elevation rules=-
 Enter rules, "end" when done, "help" if you need it.
 fp: Data range is 55.5787925720215 to 156.329864501953
 > (and prompts for input)

 # for both existing (empty) and not existing files
 $ r.colors map=elevation rules=testfile
 ERROR: Unable to load rules file <testfile>
 }}}

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2156>
GRASS GIS <http://grass.osgeo.org>