torrent2json/orig/torwrite.c

/* $Id: torwrite.c 529 2009-09-11 08:44:53Z michael $ */
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <stdint.h>
#include <stdlib.h>

const uint8_t sp=' ';
const uint8_t ret='\n';
const uint8_t quo='\"';
const uint8_t scr='\\';
const uint8_t hxp='x';
const uint8_t blst='[';
const uint8_t elst=']';
const uint8_t bdct='(';
const uint8_t edct=')';
const uint8_t eqv='=';
const int stdout=1;

enum obj_type {OBJ_NUL, OBJ_INT, OBJ_STR, OBJ_LST, OBJ_DCT};

size_t IntLen(const uint8_t* d, size_t shift, size_t len)
{
 size_t l=1;

 while(d[shift+l]>=48 && d[shift+l]<=57)
 {
  l++;
  if(shift+l==len) exit(2);
 }
 return l;
}

size_t StrLen(const uint8_t* d, size_t shift, size_t len)
{
 size_t l=0;
 size_t sh=shift+1;

 while(1)
 {
  if(d[sh]==quo) break;
  if(d[sh]==scr)
  {
   if(d[sh+1]=='x') sh+=3;
   else sh++;
  }
  sh++;
  l++;
  if(sh>=len) exit(2);
 }
 return l;
}

void PrintDec(size_t n)
{
 size_t num=n,rem;
 size_t len=0;
 uint8_t *out,*pout;

 while(num!=0)
 {
  num/=10;
  len++;
 }

 out=malloc(len);
 pout=out+len-1;
 num=n;

 while(num!=0)
 {
  rem=num%10;
  num/=10;
  *pout--=rem+'0';
 }
 write(stdout,out,len);
 free(out);
}

uint8_t Hex2N(uint8_t h)
{
 if(h>='0' && h<='9') return h-'0';
 if(h>='A' && h<='F') return h-'A'+10;
 if(h>='a' && h<='f') return h-'a'+10;
 exit(2);
}

uint8_t Hex2Sym(const uint8_t *d, size_t sh)
{
 return (Hex2N(d[sh])<<4)|Hex2N(d[sh+1]);
}

int main(int argc, char** argv)
{
 if(argc!=2) return 1;

 int fd;
 struct stat st;
 uint8_t *pdata;
 uint8_t ch,c;
 size_t shift=0,len;

 fd=open(argv[1],O_RDONLY); if(fd==-1) return 1;
 if(fstat(fd,&st)!=0) return 1;
 if(st.st_size==0) return 1;
 pdata=(uint8_t*) mmap(0,st.st_size,PROT_READ,MAP_SHARED,fd,0);

 while(shift<st.st_size)
 {
  c=pdata[shift];
  if(c==bdct) {ch='d'; write(stdout,&ch,1);}
  if(c==blst) {ch='l'; write(stdout,&ch,1);}
  if(c==edct || pdata[shift]==elst) {ch='e'; write(stdout,&ch,1);}
  if((c>=48 && c<=57) || c=='+' || c=='-')
  {
   len=IntLen(pdata,shift,st.st_size);
   ch='i'; write(stdout,&ch,1);
   write(stdout,pdata+shift,len);
   ch='e'; write(stdout,&ch,1);
   shift+=len-1;
  }
  if(c==quo)
  {
   len=StrLen(pdata,shift,st.st_size);
   PrintDec(len); ch=':'; write(stdout,&ch,1);
   shift++;
   while(1)
   {
    c=pdata[shift];
    if(c==quo) break;
    if(c==scr)
    {
     shift++;
     c=pdata[shift];
     if(c=='x')
     {
      shift++;
      ch=Hex2Sym(pdata,shift);
      shift++;
     }
     else
     {
      switch(c)
      {
      case('n'): {ch='\n'; break;}
      case('a'): {ch='\a'; break;}
      case('b'): {ch='\b'; break;}
      case('e'): {ch='\e'; break;}
      case('f'): {ch='\f'; break;}
      case('r'): {ch='\r'; break;}
      case('t'): {ch='\t'; break;}
      case('v'): {ch='\v'; break;}
      default: ch=c;
      }
     }
    }
    else ch=c;
    write(stdout,&ch,1);
    shift++;
   }
  }
  shift++;
 }

 munmap(pdata,st.st_size);
 close(fd);
 return 0;
}