File signature
 

Hi
I have a process that requires a user to open one of several different xls
files, each has a specific format and I wish to decide which type of file
the user has opened.
Row one comprises a set of column headings which for each file type should
be the same, I plan to store a signature based on these headings and check
the file just opened against each of these signatures. My question is what
is best way of creating these signatures ?

I had considered using a concatenation of each column heading (trimmed) but
in some cases the signature is over 1000 characters. Is there some form of
encoding I can use to convert these into a shorter string that will detect
the file type and most cases spot if the user opens a un-recognised file
type or the source file headings have changed in some way?

TIA

--
Cheers
Nigel

File signature
 

Why not use a DocumentProperty? It's simple, unambiguous, and easy to work
with...


"Nigel" wrote in message
...
Hi
I have a process that requires a user to open one of several different xls
files, each has a specific format and I wish to decide which type of file
the user has opened.
Row one comprises a set of column headings which for each file type should
be the same, I plan to store a signature based on these headings and check
the file just opened against each of these signatures. My question is
what
is best way of creating these signatures ?

I had considered using a concatenation of each column heading (trimmed)
but
in some cases the signature is over 1000 characters. Is there some form
of
encoding I can use to convert these into a shorter string that will detect
the file type and most cases spot if the user opens a un-recognised file
type or the source file headings have changed in some way?

TIA

--
Cheers
Nigel

File signature
 

Regrettably the files to open are created elsewhere and this property is not
set. I have no control over it.

--
Cheers
Nigel



"Jezebel" wrote in message
...
Why not use a DocumentProperty? It's simple, unambiguous, and easy to work
with...


"Nigel" wrote in message
...
Hi
I have a process that requires a user to open one of several different
xls
files, each has a specific format and I wish to decide which type of
file
the user has opened.
Row one comprises a set of column headings which for each file type
should
be the same, I plan to store a signature based on these headings and
check
the file just opened against each of these signatures. My question is
what
is best way of creating these signatures ?

I had considered using a concatenation of each column heading (trimmed)
but
in some cases the signature is over 1000 characters. Is there some form
of
encoding I can use to convert these into a shorter string that will
detect
the file type and most cases spot if the user opens a un-recognised file
type or the source file headings have changed in some way?

TIA

--
Cheers
Nigel

File signature
 

You could hash them (Google will give you any number of hashing algorithms).
Or run a test and check how many of these headings you need to concatenate
to create a unique identifier.


"Nigel" wrote in message
...
Regrettably the files to open are created elsewhere and this property is
not
set. I have no control over it.

--
Cheers
Nigel



"Jezebel" wrote in message
...
Why not use a DocumentProperty? It's simple, unambiguous, and easy to
work
with...


"Nigel" wrote in message
...
Hi
I have a process that requires a user to open one of several different
xls
files, each has a specific format and I wish to decide which type of
file
the user has opened.
Row one comprises a set of column headings which for each file type
should
be the same, I plan to store a signature based on these headings and
check
the file just opened against each of these signatures. My question is
what
is best way of creating these signatures ?

I had considered using a concatenation of each column heading (trimmed)
but
in some cases the signature is over 1000 characters. Is there some
form
of
encoding I can use to convert these into a shorter string that will
detect
the file type and most cases spot if the user opens a un-recognised
file
type or the source file headings have changed in some way?

TIA

--
Cheers
Nigel