Re: how to read one line from a datafile at a time?

["cino hilliard" <hillcino368@hotmail.com>]

> You can use
> a=readvec(file);
> then
> a[1] is the value of the first line, a[2] the value of the second line, 
> etc.
>
> Cheers,
> Bill.
Why can't we get the typical gcc file I/O functions and the Win32 API built 
right in to the interpreter?

If I could get windows to compile the gp source, i would do this myself and 
I don't have the time
nor desire to learn Linux but I can't. For example suppose I want to read a 
300+ gig file of the first
1 trillion primes store 8byte wall to wall in a file on a server
Dell8200\\h8200\\sievedata\\prime2-1trill.bin".

Then say I want to read the 37,000,000,007-th prime.  Here is how I do it 
now.

prime2(n) =   \\ the nth prime using c:\sieve\prime.exe calling
             \\ Dell8200\\h8200\\sievedata\\prime2-1trill.bin"
             {
             local(x,s);
             s=concat("c:/sieve/prime ",Str(n));
             s=concat(s," > temp.txt");   \\Must save to a temp file for 
correct output
             system(s);
             return(read("temp.txt"))
             }

/*****gcc 3.4.4 command line code to read the n-th prime < 1 trillion.*****/

#include <windows.h>    // Win32 Header File
#include <stdio.h>
#define chr64(a) ulltoa(a,str,10)
static char    fil[50],fil2[50];
static HANDLE  H;
static DWORD   Read;
static int     recl;
static long     high;
static char     str[30];

int main(int argc, char *argv[])
{
unsigned long long n;
strcpy((char*)fil,"\\\\Dell8200\\f\\sievedata\\prime2-1trill.bin");
unsigned long long buffer,offset,b;
unsigned long long j;
 n=atoll(argv[1]);
 b=536870913;
 recl=8;
 H=CreateFile(fil,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,0,0);
 high=n/b;
 offset=recl*(n-1);
 SetFilePointer(H,offset,&high,FILE_BEGIN);
 ReadFile(H,&buffer,recl,&Read,NULL);
 printf("%s",chr64(buffer));
 CloseHandle(H);
 return 0;
}

This is awkward but it works pretty well.

Maybe someone out there who can compile gpcan build a set of functions to do 
this and offer the
compiled windows version for download as say, gpE or gp extended.

Maybe this feature along with typical gcc I/O functions could be built into 
the kernel?

Pest from the west,
Cino hilliard