Sun, 17 Aug 2003 12:05:09 GMT

SEEK a text file ?

Quote
> I'm making a program to go with TNM (www.tnm7.com), and I have found that for
> some things I need to seek to a certain position in a file. The problem is, the
> files have to be read as TEXT files, so I can't use the SEEK function. Any
> suggestions ?

   There are a number of ways to do such a thing, but the best solution
can't be chosen until we (you) know some features of the true
requirements.  The first thing I'd want to know is, how _much_ data is in
this file?  It's quite possible that you could read and store the whole
file in memory and access it in a variety of (fast) ways there.  It's the
first thing I'd try...
   Then, if the file is too large, there are ways to build pointers to
each "record" (by reading it once and determining the byte offset of each
record - to be read not as a text file but a byte/character file with
typed or untyped I/o.  You could create the "index/offset" table as a
separate file, once the data file exists, or construct the table "on the
fly" when the program starts.
   Yet another way is to construct a typed file from the Text data file
and process it in an entirely different way.  Such a decision would
depend on how much dynamic access you actually need, versus how much
time/effort creating a different file type would take.
   Of course, you can open/read the file sequentially each time you need
to access a specific record, but that's very slow and clumsy.
   All told, you need to know more about what, why, how much, how fast,
and how often you need to do the thing you ask...