c_eread - Random reads from an image file

SYNTAX

#include "las.h"

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

     int                *fdesc;
     long               *eband;
     long               *eline;
     unsigned char      *euserbuf;
     long               *nl_blk;

PARAMETERS

fdesc (input, integer)

File descriptor to be used internally by the image I/O subroutines. The calling routine should pass by reference the integer 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