GetFilepart bug

[williamvanhoecke]

Debug Len(GetFilePart("C:\PureBasic\PB.exe"))
Debug Len(GetFilePart("C:\PureBasic\PB.exe",#PB_FileSystem_NoExtension))

Debug Len(GetFilePart("C:\PureBasic\.exe"))
Debug Len(GetFilePart("C:\PureBasic\.exe",#PB_FileSystem_NoExtension))

results in
6
2
4
4

should be
6
2
4
0



// Moved from "Bugs - Windows" to "Coding Questions" (Kiffi)

[jacdelad]

Not a bug, the prefix can't be empty. This file has no extension, the whole name is the prefix.

[BarryG]

But there is no file part? And the manual doesn't say anything about a prefix requirement.

Code: Select all

file$=".exe" ; No file part specified (just an extension).
Debug GetFilePart(file$,#PB_FileSystem_NoExtension) ; ".exe" - why? This is not the file part.

[jacdelad]

Interesting question.

[BarryG]

Workaround:

Code: Select all

Procedure.s GetFilePartEx(file$,flags)
  file$=GetFilePart(file$)
  If Left(file$,1)="." And CountString(file$,".")=1
    file$=""
  EndIf
  ProcedureReturn GetFilePart(file$,flags)
EndProcedure

Debug GetFilePart("C:\PureBasic.exe",#PB_FileSystem_NoExtension) ; "PureBasic" - Right.
Debug GetFilePart("C:\.exe",#PB_FileSystem_NoExtension) ; ".exe" - Wrong.

Debug GetFilePartEx("C:\PureBasic.exe",#PB_FileSystem_NoExtension) ; "PureBasic" - Right.
Debug GetFilePartEx("C:\.exe",#PB_FileSystem_NoExtension) ; "" - Right.

[normeus]

".exe" is a valid filename, just like ".htaccess" they just don't have extensions.

Code: Select all

Debug Len(GetFilePart("C:\PureBasic\.exe"))    ; 4 character filename
Debug CheckFilename("C:\PureBasic\.exe")      ; returns 0 if a valid filename

[EDIT]
another example

Code: Select all

Debug GetFilePart("C:\.ForgotToCheckVarForFilename.lechat.thecat.diekatze.ilgatto",#PB_FileSystem_NoExtension)
Debug GetExtensionPart("C:\.ForgotToCheckVarForFilename.lechat.thecat.diekatze.ilgatto")

Norm.

[williamvanhoecke]

I have this software where customer enter a raw 'name' for there file and the extention is then automatically added.
I then check is a 'name' was entered and if it is valid with CheckFilename(name).
So i get things like "C:\user\benjamin\customerfiles\.lti"

Realy I don't care if ".lti" is a valid filename or not, since ".lti" is the extention the len(getfilepart(".lti",#PB_FileSystem_NoExtension)) should give 0

Since I know there IS an extention my workaround is simple
if Len(StringField(GetFilePart(filename),1,".")) = 0 --> no filename here

[Demivec]

No bug in the original post.

https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file

Relevant quotes from the above link:

Use a period to separate the base file name from the extension in the name of a directory or file.

However, it is acceptable to specify a period as the first character of a name. For example, ".temp".

Since a period is used as a separator between a filename and an extension, a period as the first character is part of the filename since there is no filename yet to mark a separation from for an extension to occur.

[williamvanhoecke]

@normeus

".exe" is a valid filename, just like ".htaccess" they just don't have extensions.

That may correct but then how do you know if you have "an empty filename with an extention" or "A weired legal filename with no extention" ??
Unless your running a server, I think its not a good practice to start filnames with a dot, makes as you see things complicated.

As Einstein said "All solutions must be simple...." wouldend it be great, left from the dot is the filname, right from the dot is the extention

[williamvanhoecke]

So
I read all the replies, they are all correct.
There is no bug, for the system,
since filename ".lti" is a legal filename with no extention.

but from the users or programmers point of view the GetFilePart(filename,#PB_FileSystem_NoExtension) can NEVER work correctly .
since filename ".lti" can be
a legal filename with no extention
an empty (illegal) filename with an extention (as in my case)

Conclusion, nothing needs to be fixed, just work around it.

[BarryG]

how do you know if you have "an empty filename with an extention" or "A weired legal filename with no extention" ??

In such a case, you can't ever know. It's a problem without a solution.

[Little John]

@normeus

".exe" is a valid filename, just like ".htaccess" they just don't have extensions.

That may correct but then how do you know if you have "an empty filename with an extention" or "A weired legal filename with no extention" ??

Since e.g. ".exe" and ".htaccess" are valid file names, an empty filename with an extension simply does not exist. That's by definition, and it doesn't matter whether or not someone likes it.

Unless your running a server, I think its not a good practice to start filnames with a dot, makes as you see things complicated.

What is good practice and what is not is a different question. This is not a bug in PureBasic.

[NicTheQuick]

On Linux files starting with a dot are treated as hidden files. The name `.config` is basically a file named `config`, but hidden.

[jacdelad]

So, after a long discussion we're back to what I said in my first post.
I guess GetFileExtension() just delivers the part after the last ".", regardless of what is in front of it.

[Little John]

So, after a long discussion we're back to what I said in my first post.

Yep.

I guess GetFileExtension() just delivers the part after the last ".", regardless of what is in front of it.

There is no GetFileExtension() function in PureBasic.
You probably mean GetExtensionPart(). As far as I can see, its behaviour is consistent with GetFilePart() (PB 6.03 LTS on Windows).