determining a plain text file

[J. Landman Gay]

Scott Morrow wrote:
> 
> Does anyone have a method for determining whether a file is plain text 
> that they would be willing to share?

On most platforms, you can just check whether the last four characters 
of the file name are ".txt". On MacOS and OS X you should probably also 
check the file type, since Mac files don't always have an extension. 
However, note that many OS X apps do not set creator/type codes when 
creating new files, so you may find that some files have creator/type 
codes of "????????". In this case, you've got to rely on the extension 
if there is one.

To check the file type, set the defaultFolder to the folder that 
contains the file. Then get "the detailed files" and parse the resulting 
list to find the file you want to know about. The last item in the line 
will be the file type and creator code, and the first four characters of 
that should be "TEXT" if it is really a text file.

Here is one way to do it:

function getFileType
   answer file "Choose a file:"
   if it = "" then return empty
   set the itemdel to slash
   put last item of it into tFileName
   put item 1 to -2 of it into tFolder
   set the itemDel to comma
   put urlEncode(tFileName) into tFileName
   set the defaultFolder to tFolder
   put the detailed files into tFileList
   put line lineoffset(tFileName,tFileList) of tFileList into tFileInfo
   return (char 1 to 4 of last item of tFileInfo = "TEXT")
end getFileType

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com