使用golang读取StarDict 词典idx文件并按行输出

StarDict 词典idx文件格式：

每一个条目在单词列表中包含陆续三个域：

word_str;                 // a utf-8 string terminated by '\0'.

                                  // 一个 utf-8 编码字符串，以 '\0' 终止符结束。word_str 的长度将是小于 256 的

word_data_offset; // word data's offset in .dict file

                                  // 单词数据在 .dict 文件中的偏移，

                                  //If the version is "3.0.0" and "idxoffsetbits=64", 

                                  //word_data_offset will be 64-bits unsigned number in network byte order. 

word_data_size;   // word data's total size in .dict file

                                  // 单词数据在 .dict 文件中的总大小，word_data_size should be 32-bits unsigned number

                                  // in network byte order.

package main


import (
//    "bufio"
    "io"
    "os"
    "fmt"
     "strconv"
)
func main() {
    fi, err := os.Open("gaojihanyudacidian_fix.idx")/*现代汉语词典\\*/
    if err != nil { panic(err) }
    defer fi.Close()

    fo, err := os.Create("output.txt")
    if err != nil { panic(err) }
    defer fo.Close()
	/*每次只读4个字节*/
    read_buf := make([]byte,4)
    jiange := make([]byte,1)
    huanghuang := make([]byte,1)
    jiange[0]=9
     huanghuang[0]=10   
    var pos,nextPos uint64 = 0,0

    /*标记当下需要读取的是哪个域的数据
    为1是word_str  
    为2是word_data_offset  
    为3是word_data_size*/ 
    var setp int = 1  
    /*记录已经存储在word_str中的字符个数（不包括字符串最后的\0），也就是说下次从word_str[lenth_of_word_str]处开始存*/
    var lenth_of_word_str,charNum int = 0,0
    word_str := make([]byte,257)
    var tmpChar byte =0
    var word_data_offset uint64 = 0  
    var word_data_size uint64 = 0    
    count :=1
    for{
    	pos=nextPos
	count++
        n,err := fi.ReadAt(read_buf,(int64)(pos))
        if err != nil && err != io.EOF{
            panic(err)
        }
        /*文件格式要求：读取数据小于4个字节时说明文件结束*/
        if   n < 4{
            fmt.Printf("\nfinish read\n")
            break
        }
	switch setp {
	case 1:
//		fmt.Println("1:")
		tmpChar=read_buf[0]
		/*如果第一个字符是‘\0’说明该步骤已经结束*/
		if  tmpChar !=  0{
		
			/*因为可能有逗号，所以可能只有1个或者俩个字节组成一个字符*/
			if tmpChar < 128{
				charNum=1/*charNum记录utf8编码的字符数*/
			}else if tmpChar < 194{
				panic(err)
			}else if tmpChar < 224{
				charNum=2
			}else if tmpChar < 240{
				charNum=3
			}else{
				panic(err)
			}
			
			
			read_buf[charNum]=0
			str1 := (string)(read_buf[0:charNum+1])
			copy(word_str[lenth_of_word_str:lenth_of_word_str+charNum], read_buf[:charNum])
			lenth_of_word_str=lenth_of_word_str+charNum
			nextPos=nextPos+(uint64)(charNum)
			continue
		}else{
			word_str[lenth_of_word_str]=9
			nextPos=nextPos+1
			
		}		
		
        	
	case 2:

		word_data_offset  =0
		word_data_offset  = word_data_offset+((uint64)(read_buf[0]))*16*16*16*16*16*16
		word_data_offset  = word_data_offset+((uint64)(read_buf[1]))*16*16*16*16
		word_data_offset  = word_data_offset+((uint64)(read_buf[2]))*16*16
		word_data_offset  = word_data_offset+(uint64)(read_buf[3])
		nextPos=nextPos+4
		
//        	fmt.Printf("word_data_offset  =%d   \n",word_data_offset/*(uint64)(read_buf[3])*/)
	case 3:

		word_data_size  =0
		word_data_size  = word_data_size+(uint64)(read_buf[0])*16*16*16*16*16*16
		word_data_size  = word_data_size+(uint64)(read_buf[1])*16*16*16*16
		word_data_size  = word_data_size+(uint64)(read_buf[2])*16*16
		word_data_size  = word_data_size+(uint64)(read_buf[3])
		nextPos=nextPos+4

	default:

        }
        /*现在可以写入了*/

	if setp == 3{
	
		if _,err := fo.Write( word_str[:lenth_of_word_str+1]); err != nil{
		    panic(err)
		}
		
	        word_data_offset_str := strconv.FormatUint(word_data_offset,10)  
	        word_data_size_str := strconv.FormatUint(word_data_size,10)   		
		if _,err := fo.WriteString(  word_data_offset_str); err != nil{
		    panic(err)
		}
 		
		if _,err := fo.Write( jiange[0:1]); err != nil{
		    panic(err)
		}		
		if _,err := fo.WriteString( word_data_size_str); err != nil{
		    panic(err)
		}		
		if _,err := fo.Write( huanghuang[0:1]); err != nil{
		    panic(err)
		}
		lenth_of_word_str=0
	}
        setp=setp+1
        if setp > 4{
		setp = 1   
	}
    }
}