ConvertReadLong

Syntax

int ConvertReadLong(int fp,int64 *val);

Header

base/rconvert.h

Library

Description

The ConvertReadLong function reads a variable of type int64 (64-bit integer) from an open file. The bytes are assumed to be in little-endian ordered.

The bytes are read from the file with the filed descriptor given by the argument fd and the 64-bit integer number is stored at the location pointed to by the argument val.

Returns

Returns zero on success. On error, a (-1) is returned.

Errors

On error, a (-1) is returned.

Example

Source Code: ConvertReadLong.c

/* ConvertReadLong.c
   =================
   Author: R.J.Barnes
 Copyright (c) 2012 The Johns Hopkins University/Applied Physics Laboratory

This file is part of the Radar Software Toolkit (RST).

RST is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.

Modifications:



#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include "rtypes.h"
#include "rconvert.h"

#define FNAME "test.dat"

int main(int argc,char *argv[]) {
  int64 val;
  int fd;  

  fd=open(FNAME,O_RDONLY);
   
  if (fd==-1) {
    fprintf(stderr,"File not found.'n");
    exit(-1);
  }
  
  while (ConvertReadLong(fd,&val)==0) {
    fprintf(stdout,"%lld'n",val);
  }   
  close(fd);
  
  return 0;
}