c_eread - Random reads from an image file

SYNTAX

#include "las.h"

int c_eread (fdesc, eband, eline, euserbuf, nl_blk)

     struct FDESC       **fdesc;
     long               *eband;
     long               *eline;
     unsigned char      *euserbuf;
     long               *nl_blk;

PARAMETERS

fdesc (input, pointer to struct FDESC pointer)

Pointer to the file descriptor pointer obtained from c_eopenr().

eband (input, integer)

Band number of the file to read.

eline (input, integer)

Line number to read relative to the starting line it was opened to. (i.e. 1,2,3...)

euserbuf (input, byte array)

User's buffer where the data read is to be placed.

nl_blk (input, integer)

The number of lines to be read at one time.

DESCRIPTION

The c_eread() call is used to read particular line(s) of a particular band from a file. The amount of data read for a particular line is determined from the ns parameter on the c_eopenr() call and the nl_blk parameter. c_eread() will return the total number of samples actually read.

RETURN VALUE

c_eread() returns

     Total number of samples read for success
     E_FAIL (-1) --> failure