C Question reading from and to files

[albs]

Hello,

I am studying surveying and writing a program to help my needs. So far this program reads my input file and performs what i want by outputting it to another file. I then after displaying that information want to Re-read the same file into my while loop and perform some adjustment computations to it through Least Sqaures. The problem is when i try to reopen that file it will not work.

I have tryed fclose(in);
then reopening. didnt work.
and also i tryed rewind(in);
and it compiles but doesnt work.

How do i reopen this file and get data from it again without shooting this information to a whole new file?

thank you in advance.

[sicarie]

How big is the file? Can you hold it all in memory and manipulate it as you need to?

[albs]

the file contains about 500 traverse points. each including and elevation northing easting backsight and forsight. so the file isnt way to big.

[JosAH]

Can you show a bit of relevant code? Closing the file and reopening it again
should work.

kind regards,

Jos