Adding Important sentence to FileCreateDir documentation Topic is solved

[Avtem]

Hello. So today i spent about 3 hours trying to understand why AHK doesn't create directories with FileCreateDir command. Only by accident i found out why AHK FileCreateDir command didn't work. Turns out it only partially supports forward slashes (by accident you can assume that they work). But the problem - AHK doesn't support them.
i think there are a lot of people that prefer forward slashes over back slashes (especially when you have to type them 2 times in regEx, source code, etc.) and my note could really help them out.

So, i really would like to add this sentence to the FileCreateDir command in description of the 1st parameter:

Name of the directory to create, which is assumed to be in %A_WorkingDir% if an absolute path isn't specified.
Note: path must contain only backslashes (\)

[gregster]

Note: path must contain only forward slashes (/)

Isn't that suggested sentence the opposite of what you have discovered?!

So, the lesson is: when working with paths, use backslashes only

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FileCreateDir c:/111/222/333     ; FAILS - won't create anything
FileCreateDir c:\111\222\333     ; SUCCEEDS - works as expected. All folders are created

[Ragnar]

Wow, I didn't realize until today that FileCreateDir only supports backslash.

@lexikos this might be worth considering to support forward slash for FileCreateDir (and DirCreate). All other path-related commands, functions etc. seem to support both slash types.

[iseahound]

I feel like I ran into this bug in the past... But generally with very few exceptions, such as the Open File dialog, a forward slash is a backslash.

UNC paths are another exception: Run in cmd with and without \\?\

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start "" "//?/C:/Windows/notepad.exe"

[Avtem]

@gregster
Oh, jeez! You are right, how did i mess that up?) Fixing it now!

[Ragnar]

Thanks for reporting. Changes added in PR #570.

[Avtem]

@Ragnar
Thank you as well)

[teadrinker]

Actually forward slashes work in this command if all parent directories already exist:

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FileCreateDir %A_Desktop%/NewDir
FileCreateDir %A_Desktop%/NewDir/NewDir

[lexikos]

All other path-related commands, functions etc. seem to support both slash types.

As far as I can tell, this is all of the code in AutoHotkey which explicitly supports '/' as a path separator:

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if (*cp == '\\' || *cp == '/')

That's in the file loop code, and was probably added when I added long path support.

None of the other functions explicitly support forward-slash. If it works, it is only because the system handles it. Some functions use GetFullPathName to normalize the path, and that takes care of slashes. Most functions just pass the path to whatever system function.

SplitPath explicitly supports URLs like file://whatever, so supports '/' for those; but still doesn't support it for other file paths.

I don't currently care about this enough to do a code review and fix these issues myself. Not even the shell (in Windows 11) supports forward slash.

[Ragnar]

I have created PR #300 which supports the use of forward slashes in FileCreateDir. Strictly speaking, it is a breaking change for coders who rely on the current behavior, however, their number should be very small. Moreover, I strongly doubt that this command is used very often.

[Avtem]

@Ragnar Since the topic is about slashes, i could also add that some WinAPI functions support only backslashes as well. For example
keyExists := !DllCall("RegOpenKeyExW", "PTR", 0x80000001, "wstr", keyPathWithoutRoot, "UINT", 0, "UINT", 131097, "PTR*", hKey)

[Ragnar]

I have added some notes in SplitPath and DllCall regarding slash usage via PR #570.

[lexikos]

Strictly speaking, it is a breaking change for coders who rely on the current behavior,

I'm not sure that fixing broken, undocumented behaviour - that couldn't be construed as useful - would be counted as a breaking change. To rely on it, one would have to:

• have some requirement that if the parent directory does not exist, the command must abort;
• observe that using '/' prevents the preceding directory from being created; and
• decide to use '/' for that purpose, relying on the command to avoid creating parent directories despite that behaviour directly contradicting the documentation:

This command will also create all parent directories given in DirName if they do not already exist.

[joedf]

Forward slashes work for me in Windows 10 / shell, both in cmd and file explorer.

[lexikos]

Forward vs. back slash is generally only an issue when the program or API interprets the path for some purpose, and isn't merely passing it (directly or indirectly) to a Win32 function.

I had the impression forward slashes didn't work with shell-related UI, because I tested it, and it didn't work. It doesn't work consistently, even on Windows 11. For instance, if I type or copy C:/ into the file name field of a standard open/save file dialog and press Enter, it tells me the filename is invalid, whereas C:\ navigates there. This is true for Notepad (the new Windows 11 version), Wordpad, Visual Studio 2022, Firefox, SciTE, and probably most others. Oddly, it works with Notepad++.

By "shell" I mostly meant File Explorer and "shell32", which always seemed to have more stringent (unnecessary) restrictions on filenames than the underlying Win32 functions; but there are a couple of easy examples where forward slashes don't work with cmd.exe:

• Tab completion. For example, type C:\ and press Tab, then compare to C:/ while in some other directory.
• dir C:/Windows -> Parameter format not correct - "windows".

[safetycar]

dir C:/Windows -> Parameter format not correct - "windows".

If it's worth the mention, I tried with quotes arround the path and it worked (W10).

[TAC109]

in Windows and DOS, \ is the directory separator, and / introduces a switch or parameter to a command. In my opinion, the fact that Windows makes allowances for Unix and html users and sometimes accepts / as a directory separator does not need to be documented in AutoHotkey. Users should be encouraged to use the standard \ directory separator, and the AutoHotkey documentation should reflect this.

Cheers

[joedf]

@lexikos I see, understood. I haven't tried windows 11 yet.

[lmstearn]

It was once possible back in the day to change backslash to forward slash and forward slash to dash in config.sys, and forward slash can still be used today with cmd. Type C:/Program Files/AutoHotkey in explorer (W10) and it bounces the slashes around to back!
Another issue is when \ and / are mixed in pathnames- which no doubt would bring in quite a bit of overhead and bugs to AHK and existing scripts. Edit: well possibly in existing scripts, like in odd situations where #EscapeChar.htm has been used to redefine the forward slash as an escape char.