topic Re: Read a binary file in Operating System - HP-UX

Read a binary file

Mokkarala Prakash — Tue, 02 May 2000 09:07:09 GMT

Hi folks,

I need some help! I am trying to read a binary file in my HP-C program. Fopen
command does not distinguish between the binary and text files. So i have
decided to use a system command to tell HP that I am bringing in a binary file.
Is this the right way? If it is how do I convey my message using file command ?
Thanks.

Re: Read a binary file

Paul Hite_2 — Tue, 02 May 2000 09:44:37 GMT

Just use fopen. There is no way to inform the kernel that the file is an
"ascii file" or "binary file". The kernel doesn't care. It just opens the
file and delivers the bytes.

Re: Read a binary file

Mokkarala Prakash — Tue, 02 May 2000 11:55:55 GMT

I still can't get the value I am supposed to; This is what I am doing:

fp=fopen("bxr27700.12r","r");
fscanf(fp,"hu\n",&s);/* reading a unsigned short integer*/
printf("%hu\n",s);

I get a value 0;

Once this works, I will be swapping bytes to convert to big-endian ( from
little endian).
Thanks for the help so far!

Re: Read a binary file

Paul Hite_2 — Tue, 02 May 2000 13:04:12 GMT

fscanf is a function, which, as you have used it, is going to try to convert
ascii to binary. This would appropriate if you were reading a tty to load a
value in a binary number.

In your case, no conversion is needed. You just want 2 bytes to be read.
Change your second line to:

fread(&s, sizeof s, 1, fp);

This will read the first two bytes of your file and store them in s. Use "od
-d" on your input file to verify the result.

Re: Read a binary file

Mokkarala Prakash — Tue, 02 May 2000 14:22:58 GMT

Thanks Paul, it worked, at last. Your help is very much appreciated. Now, I can
have a good night's sleep.