More details on G`MIC substitution rules? Also, rules for filenames.

Software G'MIC
1

On the substition rules, there is lack of commonly used names for $_os, and $_host.I would like to know all of them though in my case for now, $_os is what matters. What I am going to do is to make a G’MIC script that will output acceptable filenames (More on that below). Maybe that should be part of output command though.

On $_os:

  1. Windows → windows

On $_host:

  1. cli → cli
  2. krita → krita
  3. gimp → gimp
  4. Paint.NET → paintdotnet
  5. 8bf → plugin8bf

~~ @PDN_GMIC: Please confirm on 8bf. ~~

So, on $_os, I do not know what would be the remaining output. Mac → mac? Linux → linux?

As I have mentioned there are rules for file names, I have found these.

On Windows: Naming Files, Paths, and Namespaces - Win32 apps | Microsoft Docs

On Linux: https://www.cyberciti.biz/faq/linuxunix-rules-for-naming-file-and-directory-names/

On Mac: Illegal Filename Characters on Windows vs Mac OS | Black Belt Review

From what I can gather, the universal rules are:

1.There can be no characters on the following list:

  • <
  • >
  • :
  • >
  • "
  • /
  • \
  • |
  • ?
  • *
  • &

2.Filename cannot be ASCII NULL.
3.There cannot be consecutive period. A filename cannot begin with a dot either.
4.None of the reserved names are permitted

  • CON
  • PRN
  • AUX
  • NUL
  • COM1
  • COM2
  • COM3
  • COM4
  • COM5
  • COM6
  • COM7
  • COM8
  • COM9
  • LPT1
  • LPT2
  • LPT3
  • LPT4
  • LPT5
  • LPT6
  • LPT7
  • LPT8
  • LPT9
  1. Maximum number of character is 31. Could be outdated. 255 as maximum.

Note: | can be replaced with l or 1.

Edit: Thanks PDN_GMIC for specifying hostname.

2

Filenames often begin with a dot.

There cannot be consecutive period.

In Windows and bash (Cygwin bash on Windows), double dots are permitted. But I think using this would be unwise.

3

I think I will settle for a command that output fixed filename. Just pushed it to G’MIC. It follows all the universal rule except for string length < 32.

But I think using this would be unwise.

Of course, I think they should be automatically replaced with underscore instead. There’s also the mistakening of double extensions as well.

4

The 8bf host name is plugin8bf. In C and C++ the preprocessor definition names cannot start with a number.

Not a dot by itself, the . and .. file names are reserved as shorthand for the current and parent directories respectively. A file name can start with a dot, e.g. .temp .
From the MSDN page you linked to:

Use a period as a directory component in a path to represent the current directory, for example “.\temp.txt”.
…
Use two consecutive periods (..) as a directory component in a path to represent the parent of the current directory, for example “..\temp.txt”.
…
Do not end a file or directory name with a space or a period. Although the underlying file system may support such names, the Windows shell and user interface does not. However, it is acceptable to specify a period as the first character of a name.

The 1-31 reference is describing that ASCII control characters are illegal in a file name.
In ASCII the 0-31 range is used for control characters, e.g. the \r (Carriage Return) and \n (Line Feed) values used as line terminators in a text file. https://www.ascii-code.com/ has a table listing the ASCII control characters.

On most versions of Windows the total path length cannot exceed 260 characters, see Maximum Path Length Limitation for details.

5

Hi Reptorian,
Are you also talking about:

when using a GMIC plugin I choose New Layer, Apply and it puts a new layer into my image
GMIC names that new layer
Are you talking about this too?

Because if you are, currently GMIC is putting in #1, #2 etc. Then when I export the layers that number sign is in their filenames. And number signs are not supposed to be in a filename. And especially Dropbox doesn’t accept number signs etc in filenames.

At one time GMIC would name the new layer with the name of the plugin that was applied to it. That was really nice!

i have a sneaking thought though that you are only talking programming talk. If so, please don’t be offended by my question.

6

That is also applicable. That does provide incentive to update one of my commands which forces string input to be restricted with only names that is allowed by most OS (Ignoring obscure ones that no one will ever use, and never heard of).

EDIT: I have just pushed a change to a command I use which enforces correct file names.

1 Like