www.pudn.com > C中MODEM的开发.zip > MINIRB.C

/* 
 * minirb.c By Chuck Forsberg Omen Technology INC 
 *        "The High Reliability Communications Software" 
 * 
 * A bootstrap program for Unix to receive files from computers running 
 *  YMODEM Batch (Professional-YAM, PowerCom, ZCOMM, etc.). 
 * 
 *  Minirb uses system(3) to call stty, avoiding system dependent code. 
 *  Please refer to rz.c for comments, etc. 
 */ 
char * Version = "minirb 1.00 11-15-86"; 
 
#include  
#include  
#include  
#include  
 
#define OK 0 
#define FALSE 0 
#define TRUE 1 
#define ERROR (-1) 
#define CAN ('X'&037) 
#define SOH 1 
#define STX 2 
#define EOT 4 
#define ACK 6 
#define NAK 025 
#define TIMEOUT (-2) 
#define RETRYMAX 9 
#define WCEOT (-10) 
 
FILE *fout; 
long Bytesleft; 
int Blklen; 
char secbuf[1024]; 
char linbuf[1024]; 
int Lleft=0; 
jmp_buf tohere; 
 
alrm() { longjmp(tohere, -1); } 
 
bibi(n) { 
 canit(); mode(0); 
 fprintf(stderr, "minirb: caught signal %d; exiting", n); 
 exit(128+n); 
} 
 
mode(n) { 
 if (n) system("stty raw -echo"); 
 else system("stty echo -raw"); 
} 
 
main() { 
 mode(1); 
 if (signal(SIGINT, bibi) == SIG_IGN) { 
  signal(SIGINT, SIG_IGN); signal(SIGKILL, SIG_IGN); 
 } else { 
  signal(SIGINT, bibi); signal(SIGKILL, bibi); 
 } 
 printf("minirb: Now send file(s) with \042sb file ...\042 command\r\n"); 
 
 if (wcreceive()==ERROR) 
  canit(); 
 mode(0); exit(0); 
} 
 
wcreceive() { 
 for (;;) { 
  if (wcrxpn(secbuf) == ERROR) break; 
  if (secbuf[0]==0) return OK; 
  if (procheader(secbuf)==ERROR || wcrx()==ERROR) break; 
 } 
 canit(); return ERROR; 
} 
 
 
wcrxpn(rpn) char *rpn; { 
 register c; 
 
 purgeline(); 
et_tu: 
 sendline(NAK); Lleft=0; 
 while ((c = wcgetsec(rpn, 100)) != 0) { 
  if (c == WCEOT) { sendline(ACK); Lleft=0; readline(1); goto et_tu; } 
  return ERROR; 
 } 
 sendline(ACK); return OK; 
} 
 
wcrx() { 
 register int sectnum, sectcurr, sendchar, cblklen; 
 
 sectnum=0; sendchar=NAK; 
 for (;;) { 
  sendline(sendchar); Lleft=0; 
  sectcurr=wcgetsec(secbuf, (sectnum&0177)?50:130); 
  if (sectcurr==(sectnum+1)) { 
   sectnum++; cblklen = Bytesleft>Blklen ? Blklen:Bytesleft; 
   if (putsec(secbuf, cblklen)==ERROR) return ERROR; 
   if ((Bytesleft-=cblklen) < 0) Bytesleft = 0; 
   sendchar=ACK; 
  } 
  else if (sectcurr==sectnum) sendchar=ACK; 
  else if (sectcurr==WCEOT) { 
   if (fclose(fout)==ERROR) return ERROR; 
   sendline(ACK); Lleft=0; return OK; 
  } 
  else if (sectcurr==ERROR) return ERROR; 
  else return ERROR; 
 } 
} 
 
wcgetsec(rxbuf, maxtime) char *rxbuf; int maxtime; { 
 register checksum, wcj, firstch; register char *p; int sectcurr, errors; 
 for (errors=0; errors=0; ) { 
     if ((firstch=readline(1)) < 0) goto bilge; 
     checksum += (*p++ = firstch); 
    } 
    if ((firstch=readline(1)) < 0) goto bilge; 
    if (((checksum-firstch)&0377)==0) return sectcurr; 
   } 
  } 
  else if (firstch==EOT) return WCEOT; 
  else if (firstch==CAN) return ERROR; 
bilge: 
  while(readline(1)!=TIMEOUT) 
   ; 
  maxtime=40; sendline(NAK); Lleft=0; 
 } 
 canit(); return ERROR; 
} 
 
readline(timeout) int timeout; { 
 register n; static char *cdq; 
 
 if (--Lleft >= 0) return (*cdq++ & 0377); 
 n = timeout/10; 
 if (n < 2) n = 3; 
 if (setjmp(tohere)) { Lleft = 0; return TIMEOUT; } 
 signal(SIGALRM, alrm); alarm(n); 
 Lleft=read(0, cdq=linbuf, 1024); alarm(0); 
 if (Lleft < 1) return TIMEOUT; 
 --Lleft; return (*cdq++ & 0377); 
} 
 
purgeline() { Lleft = 0; lseek(0, 0L, 2); } 
 
 
procheader(name) char *name; { 
 register char *p; 
 
 Bytesleft = 2000000000L; p = name + 1 + strlen(name); 
 if (*p) sscanf(p, "%ld", &Bytesleft); 
 if ((fout=fopen(name, "w")) == NULL) return ERROR; 
 return OK; 
} 
 
putsec(buf, n) char *buf; register n; 
{ 
 register char *p; 
 for (p=buf; --n>=0; ) putc( *p++, fout); 
 return OK; 
} 
 
sendline(c) { char d; d = c; write(1, &d, 1); } 
 
char canistr[] = { 24,24,24,24,24,24,24,24,0 }; 
 
canit() { printf(canistr); Lleft=0; } 
 
/* END of minirb.c */