source: buchla-68k/orig/IOLIB/GETC.C

/*
   ============================================================================
        getc.c -- get a character from a stream file
        Version 3 -- 1987-09-22 -- D.N. Lynx Crowe
   ============================================================================
*/

#include "stdio.h"
#include "stddefs.h"

int
getc(ptr)
register FILE *ptr;
{
        register int len;

        if (ptr->_bp >= ptr->_bend) {           /* see if the buffer is empty */

                if (ptr->_flags & _EOF)         /* check EOF status */
                        return(EOF);

                ptr->_flags &= ~_DIRTY;         /* reset the dirty buffer bit */

                if (ptr->_buff EQ NULL)         /* get a buffer if none exists */
                        getbuff(ptr);

                if ((len = read(ptr->_unit, ptr->_buff, ptr->_buflen)) LE 0) {

                        ptr->_flags |= ((len EQ 0) ? _EOF : _IOERR);
                        return(EOF);
                }

                ptr->_bend = (ptr->_bp = ptr->_buff) + len;
        }

        return(*ptr->_bp++ & 0xFF);
}