从字符串标记字符串时出错

发布于 2024-11-19 18:17:19 字数 1333 浏览 4 评论 0原文

我想从 SIC 汇编代码生成符号表。为此，我尝试将每个字符串与汇编代码分开。因此，在尝试第一步时，我尝试了这段代码。

在这里，我尝试过的是逐行读取文件中的汇编代码。然后将行中的字符串分隔为标记。

当我删除标记分隔部分（如代码中所述）时，我将按预期打印所有行。但是，如果我与令牌分离一起运行，则第一行将被读取，并且令牌将按照我的预期进行分离。但对于第二行，我收到了分段错误错误。我无法追踪我哪里出错了。

所以，我需要专家的解释。

提前致谢。

 FILE* sourceCode = fopen("/home/muthu/LangFiles/SIC/PASS1/PROGRAM.txt","r");
  if(checkForFileOpeningErrors() == ERROR) //我使用单独的函数
      返回 EXIT_FAILURE； //终止程序。
  int 最大线长度 = 50;
  同时(1)
  {
           字符* lineReader = NULL; // 因为 getline 将重新分配。
       if( getline(&lineReader,(size_t*)&maxLineLength,sourceCode) == -1 )
           休息;
       printf("%s",lineReader);

// 令牌分离从这里开始....如果我注释掉这一部分，我就会打印所有行 
            字符*字读器；
      wordReader = strtok(lineReader,"\n");
      printf("%s\n",wordReader);
      同时(1)
      {
           wordReader = strtok(NULL,"\n");
           printf("%s\n",wordReader);
      }
// 令牌分离到此结束...
  }

我的文件：

COPY START 1000  
FIRST STL RETADR 
CLOOP JSUB RDREC  
LDA LENGTH
COMP ZERO
JEQ ENDFIL
JSUB WRREC 
J CLOOP
.
.
.
END

我的示例输出：

muthu@muthu-G31M-ES2L:~/LangFiles/PASS1$ ./a.out
All Files successfully opened!! Operation has begun...
COPY START 1000 

COPY
START
1000
segmentation Fault.

原文

I want to generate a symbol table from a SIC Assembly code. For that I have tried to separate every strings form the assembly code.
Hence while attempting first step for that, I tried this code.

Here,
What I have tried is to read the assembly code form a file line by line. And then to separate the strings in the line to tokens.

When I remove the token separation section (as mentioned in the code) I am getting all lines printed as expected.
But If I run along with token separation, the first line is getting read and the tokens are separated as I expected. But for the second line I am getting error as segmentation fault.
I couldn't trace where I went wrong.

So, I need explanations form experts.

Thanks in advance.

 FILE* sourceCode =  fopen("/home/muthu/LangFiles/SIC/PASS1/PROGRAM.txt","r");
  if(checkForFileOpeningErrors() == ERROR)  //Iam using separate function
      return EXIT_FAILURE;  //Terminate the program.
  int maxLineLength = 50;
  while(1)
  {
           char* lineReader = NULL;  // since getline will reallocate.
       if( getline(&lineReader,(size_t*)&maxLineLength,sourceCode) == -1 )
           break;
       printf("%s",lineReader);

// TOKEN SEPARATION STARTS HERE....   If I comment this section out iam getting all lines printed 
            char* wordReader;
      wordReader = strtok(lineReader," \n");
      printf("%s\n",wordReader);
      while(1)
      {
           wordReader = strtok(NULL," \n");
           printf("%s\n",wordReader);
      }
// TOKEN SEPARATION ENDS HERE....
  }

My FILE:

COPY START 1000  
FIRST STL RETADR 
CLOOP JSUB RDREC  
LDA LENGTH
COMP ZERO
JEQ ENDFIL
JSUB WRREC 
J CLOOP
.
.
.
END

My Sample output:

muthu@muthu-G31M-ES2L:~/LangFiles/PASS1$ ./a.out
All Files successfully opened!! Operation has begun...
COPY START 1000 

COPY
START
1000
segmentation Fault.

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悲欢浪云 2024-11-26 18:17:19

您预计该循环何时终止？

  while(1)
  {
       wordReader = strtok(NULL," \n");
       printf("%s\n",wordReader);
  }

When do you expect this loop to terminate?

  while(1)
  {
       wordReader = strtok(NULL," \n");
       printf("%s\n",wordReader);
  }

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终难遇 2024-11-26 18:17:19

呃，你使用了 strtok() 错误。当找不到更多令牌时，它将返回 NULL，并且您不应该尝试打印它。另外，你的循环是永无止境的，这将是一个问题。

循环可能看起来像这样，因为现在，您在每次迭代时将相同的参数传递给 strtok() ，这当然永远不会成功：

for(wordReader = strtok(lineReader, " \n");
    wordReader != NULL;
    wordReader = strtok(NULL, " \n"))
{
   printf("found token: '%s'\n", wordReader);
}

Uh, you're using strtok() wrong. It will return NULL when no more tokens are found, and you shouldn't try to print that. Also, your loop is never-ending, which will be a problem.

The loop should probably look something like this, since as-is now, you pass the same argument to strtok() on every iteration, which will of course never succeed:

for(wordReader = strtok(lineReader, " \n");
    wordReader != NULL;
    wordReader = strtok(NULL, " \n"))
{
   printf("found token: '%s'\n", wordReader);
}

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