View source for Talk:File extension is in extensions list

== Dupe? ==

I know it's not exactly the same but is this a close duplicate of [[Search a list]]? This one has an odd requirement that it has to be a file extension, but the other one has the extra requirement of using an indexed list. I think they're close enough and Search a list has the advantage of already being implemented a lot and not restricting the data. --[[User:Mwn3d|Mwn3d]] ([[User talk:Mwn3d|talk]]) 16:56, 11 August 2014 (UTC)

: Well, the file extension has to be parsed, and there is the case of the filename not having an extension (so the requirement of having to have a file extension ... isn't). &nbsp; The handling of insensitive case is a minor requirement. &nbsp; It's a common enough task to warrant it's own task. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 20:28, 11 August 2014 (UTC)

: Also, just to note, some filenames that have no file extenstion:

::::* somefile
::::* holy smoke
::::* afile.
::::* /a/path/to/glory.yup/or_not
::::* funny...
::::* unusual.½xy 
::::* fly_in_the_ointment. imbedded_blank_after_the_period

-- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 20:28, 11 August 2014 (UTC)
<br> -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 19:07, 12 August 2014 (UTC)  {added two more examples above.}

::I didn't read it quite right the first time and didn't see that the entire filename is an input rather than just its extension. I think it would be better to have a task for separating the file extension from the full filename without the list search task that this one is similar to. The task here is just combining two really simple tasks into an uncommon compound task. --[[User:Mwn3d|Mwn3d]] ([[User talk:Mwn3d|talk]]) 20:50, 11 August 2014 (UTC)

::: That's what I thought at first, until I (gasp!) actually read my own post) ... and found that it's not that simple (separating a file extension from a filename that may have no valid extension?) --- but certainly not that complicated, but worthy of some thought. &nbsp; I went for the boilerplate solution route (for REXX). -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 21:08, 11 August 2014 (UTC)
::::Yeah it doesn't sound very different from the search task in my head but now that I've done it I see it has some key variations--most notably (for my Java version anyway) was the case-insensitivity. --[[User:Mwn3d|Mwn3d]] ([[User talk:Mwn3d|talk]]) 17:21, 12 August 2014 (UTC)

::::: I found that the fly-in-the-ointment (above, which deals with imbedded/leading/trailing blanks) to be a bit of a thorn in one's side, but after some thought, it only took one extra REXX program statement to make it compliant, the comment dealing with it however, was a lot larger. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 20:57, 12 August 2014 (UTC)

== Differing definitions of 'extension' ==

By the usual Unix Way of thinking, the OS and shells are largely agnostic to the notion of filename extension, so each individual program will interpret the idea as it sees fit.  I see only two constraints: first, the convention that an extension must start with the final period in a filename, and second, that an extension cannot contain characters that are illegal in a filename, namely / or the null character.  Other than that, it's perfectly legal to have characters like ½ or space in a filename, and the extension is no different from the rest of the filename in that regard.  (Usual caveats, of course, since most filesystems haven't a clue what that you've encoded a Unicode character, and if you use spaces in an extension for your program, we will hunt you down and kill you. <tt>:)</tt>  --[[User:TimToady|TimToady]] ([[User talk:TimToady|talk]]) 00:31, 13 August 2014 (UTC)