www.pudn.com > 文件恢复及修补 C 语言源程序.zip > READ.C

 
/************************************************************ 
 *         IBM PC "C" Bulletin Board                        * 
 *         Tulsa, OK 918-664-8737                           * 
 *         SYSOP Lynn Long 300/1200 XMODEM                  * 
 ***********************************************************/ 
 
#include "io.h" 
#include "errno.h" 
#include "fcntl.h" 
 
int badfd(), filerd(), conin(); 
 
static int (*readtab[])() = { 
        badfd, filerd, conin, 
}; 
extern int errno; 
 
read(fd, buff, len) 
char *buff; 
{ 
        register struct channel *chp; 
 
        if (fd < 0 || fd > MAXCHAN) { 
                errno = EBADF; 
                return -1; 
        } 
        chp = &chantab[fd]; 
        return (*readtab[chp->c_read])(chp->c_arg, buff, len); 
} 
 
conin(x,buff,len) 
char *buff; 
{ 
        static char buffer[258] = { 0,0,0,0,0 }; 
        static int used = 0; 
        register int l; 
 
        if (buffer[1] == 0) { 
                buffer[0] = 255; 
                buffer[1] = buffer[2] = 0; 
                bdos(10,buffer); 
                bdos(2,'\n'); 
                if (buffer[2] == 0x1a) { 
                        buffer[1] = 0; 
                        return 0; 
                } 
                buffer[++buffer[1] + 1] = '\r'; 
                buffer[++buffer[1] + 1] = '\n'; 
                used = 2; 
        } 
        if ((l = buffer[1]) > len) 
                l = len; 
        blockmv(buff, buffer+used, l); 
        used += l; 
        buffer[1] -= l; 
        return l; 
}