Differentiating between binary and ASCII input streams

[peleus]

I am currently working on a project where I will be having both binary and text information streams. If the stream is binary then I do nothing and send it on. If the stream is text then I need to do some parsing. Does anyone have a great suggestion for quickly and reliably determing whether a buffer contains binary information or not?
I'm looking at the source for the UNIX "strings" command and may steal code out of that but I thought I would check to see if there are other methods. Ideally I would want to check the first few bytes of the buffer so I don't get bugs if the first byte of the binary coincidentally maps to an ASCII character.

thanks,
-Peleus

[Unregistered]

The sender of the stream must know what type of data is being sent...maybe the stream sender can put a header record on the stream which will indicate the stream type?

[pinko_liberal]

If you mean distinguishing a file pointer obtained by opening a file in binary mode with that in text mode , I dont think this is possible using just ansi C , for in many systems there is no difference between the two modes .

[Salem]

> If the stream is text then I need to do some parsing
You can't really know the answer to this until you've read the whole file (there could be a single binary value at the last byte in the file).

You need to know something about the files you're getting in order to make this determination.

> I'm looking at the source for the UNIX "strings" command
The 'file' command is the one which determines file types.

Typically, a text file is all printable characters in the first 256 bytes of the file.

[Unregistered]

> Typically, a text file is all printable characters in the first 256
> bytes of the file.

In which case, just include ctype.h and use 'isprint()' on each byte.

Quzah.