c - 提取注释和字符串 - 已编辑

Question

这是我之前的一个问题的编辑、更正、更具体的版本。所以我正在做一个家庭作业，我们必须使用一个滑动窗口来打印来自标准输入的输入文件的注释和字符串。我非常接近，但缺少一些东西。以下是我的代码、一个输入、我的当前输出和正确的输出。 // 注释和忽略字符有效。我不确定字符串的问题，在/**/注释中我无法摆脱初始 /* 中的星号，除非搞砸它找到 */。感谢任何可以提供帮助的人。

代码:

#include <stdio.h>
typedef enum  
{  
    Initial,
    Comment,  
    String,  
    Char,
    CPPComment  
} extrema; 
int main()
{
    int c, c1 = 0, c2 = 0;
    extrema state = Initial;
    extrema next = Initial;
    while(1)
    {
        switch(state)
        {
           case Initial: next = ((c2 == '*' && c1 == '/') ? Comment : (c2 == '\"') ? String : (c2 == '/' && c1 == '/') ? Char : (c2 == '\'') ? CPPComment : Initial); break; 
           case Comment: next = ((c2 == '/' && c1 == '*') ? Initial : Comment); break; 
           case String: next = ((c2 == '\"' && c1 != '\\') ? Initial : String); break;
           case Char: next = ((c2 == '\n') ? Initial : Char); break;
           case CPPComment: next = ((c2 == '\'' && c1 != '\\') ? Initial : CPPComment); break;
           default: next = state; 
        }
        if(state == Comment)
        {
            if(c1 == '*')
            {
                if(c2 != '/')
                    putchar(c1);
                else
                    putchar('\n');  
            }
            else
                putchar(c1);
        }
        else if(state == String)
        {
            if(c2 != '\"' || (c2 == '\"' && c1 != '\\'))
                putchar(c2);
        }
        else if(state == CPPComment)
        {
                putchar(c2);
        }

        c = getchar(); if( c < 0) break;
        c1 = c2; c2 = c; // slide window
//printf("%i",state);
        state = next;
        // c2 is the current input byte and c1 is the previous input byte
    }
    return 0;
}

输入:

 /* recognize '...' otherwise see " as start of string: */

     int c='\"', d='\'', e = '\012'; // comment line 3

 /* recognize "..." otherwise see comments here: */

     char s[] = "abc/*not a comment*/efg\"ZZ\'";

     char t[] = "ABC//not a comment//EFG\x012\/\/";

char *p = ""; //

int d = '/*'; // comment line 13

/*/*/
/**/
/*Z*/
/***/
/****/
/**A**/

我的输出:

* recognize '...' otherwise see " as start of string: 
 comment line 3
* recognize "..." otherwise see comments here: 
abc/*not a comment*/efg\ZZ\'"ABC//not a comment//EFG\x012\/\/""
 comment line 13


*
*Z
**
***
**A*

正确的输出:

 recognize '...' otherwise see " as start of string: 
 comment line 3
 recognize "..." otherwise see comments here: 
abc/*not a comment*/efg\"ZZ\'
ABC//not a comment//EFG\x012\/\/


 comment line 13
/

Z
*
**
*A*

Answer 1

这里是你如何做到的:

 /* recognize '...' otherwise see " as start of string: */

     int c='\"', d='\'', e = '\012'; // comment line 3

 /* recognize "..." otherwise see comments here: */

     char s[] = "abc/*not a comment*/efg\"ZZ\'";

     char t[] = "ABC//not a comment//EFG\x012\/\/";

char *p = ""; //

int dd = '/*'; // comment line 13

/*/*/
/**/
/*Z*/
/***/
/****/
/**A**/

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char** argv)
{
  FILE* f;

  if (argc == 2 && (f = fopen(argv[1], "rt")) != NULL)
  {
    int c[2];

    enum {
      INITIAL,
      CCOMMENT1,
      CCOMMENT2,
      CCOMMENT3,
      CPPCOMMENT1,
      CPPCOMMENT2,
      STRING1,
      STRING2,
      CHAR1,
      CHAR2,
    } state = INITIAL;

    if ((c[0] = fgetc(f)) == EOF)
      return 0;

    while ((c[1] = fgetc(f)) != EOF)
    {
      switch (state)
      {
      case INITIAL:
        if (c[0] == '/' && c[1] == '*')
          state = CCOMMENT1, printf("<C comment>\n");
        else if (c[0] == '/' && c[1] == '/')
          state = CPPCOMMENT1, printf("<C++ comment>\n");
        else if (c[0] == '"')
          state = STRING1, printf("<String literal>\n");
        else if (c[0] == '\'')
          state = CHAR1, printf("<Char literal>\n");
        break;

      case CCOMMENT1:
      case CPPCOMMENT1:
        /* skip * in /* and 2nd / in // */
        state++;
        break;

      case CCOMMENT2:
        if (c[0] == '*' && c[1] == '/')
          state++, printf("\n</C comment>\n");
        else
          printf("%c", c[0]);
        break;

      case CCOMMENT3:
        // skip / in */
        state = INITIAL;
        break;

      case CPPCOMMENT2:
        if (c[0] == '\n')
          state = INITIAL, printf("\n</C++ comment>\n");
        else
          printf("%c", c[0]);
        break;

      case STRING1:
        if (c[0] == '"')
          state = INITIAL, printf("\n</String literal>\n");
        else if (c[0] == '\\')
          state = STRING2, printf("%c", c[0]);
        else
          printf("%c", c[0]);
        break;

      case STRING2:
        // skip escaped character
        state = STRING1, printf("%c", c[0]);
        break;

      case CHAR1:
        if (c[0] == '\'')
          state = INITIAL, printf("\n</Char literal>\n");
        else if (c[0] == '\\')
          state = CHAR2, printf("%c", c[0]);
        else
          printf("%c", c[0]);
        break;

      case CHAR2:
        // skip escaped character
        state = CHAR1, printf("%c", c[0]);
        break;
      }

      c[0] = c[1];
    }

    fclose(f);
  }

  return 0;
}

此程序的源代码输出:

<C comment>
 recognize '...' otherwise see " as start of string: 
</C comment>
<Char literal>
\"
</Char literal>
<Char literal>
\'
</Char literal>
<Char literal>
\012
</Char literal>
<C++ comment>
 comment line 3
</C++ comment>
<C comment>
 recognize "..." otherwise see comments here: 
</C comment>
<String literal>
abc/*not a comment*/efg\"ZZ\'
</String literal>
<String literal>
ABC//not a comment//EFG\x012\/\/
</String literal>
<String literal>

</String literal>
<C++ comment>

</C++ comment>
<Char literal>
/*
</Char literal>
<C++ comment>
 comment line 13
</C++ comment>
<C comment>
/
</C comment>
<C comment>

</C comment>
<C comment>
Z
</C comment>
<C comment>
*
</C comment>
<C comment>
**
</C comment>
<C comment>
*A*
</C comment>
<String literal>
rt
</String literal>
<Char literal>
/
</Char literal>
<Char literal>
*
</Char literal>
<String literal>
<C comment>\n
</String literal>
<Char literal>
/
</Char literal>
<Char literal>
/
</Char literal>
<String literal>
<C++ comment>\n
</String literal>
<Char literal>
"
</Char literal>
<String literal>
<String literal>\n
</String literal>
<Char literal>
\'
</Char literal>
<String literal>
<Char literal>\n
</String literal>
<C comment>
 skip * in /* and 2nd / in // 
</C comment>
<Char literal>
*
</Char literal>
<Char literal>
/
</Char literal>
<String literal>
\n</C comment>\n
</String literal>
<String literal>
%c
</String literal>
<C++ comment>
 skip / in */
</C++ comment>
<Char literal>
\n
</Char literal>
<String literal>
\n</C++ comment>\n
</String literal>
<String literal>
%c
</String literal>
<Char literal>
"
</Char literal>
<String literal>
\n</String literal>\n
</String literal>
<Char literal>
\\
</Char literal>
<String literal>
%c
</String literal>
<String literal>
%c
</String literal>
<C++ comment>
 skip escaped character
</C++ comment>
<String literal>
%c
</String literal>
<Char literal>
\'
</Char literal>
<String literal>
\n</Char literal>\n
</String literal>
<Char literal>
\\
</Char literal>
<String literal>
%c
</String literal>
<String literal>
%c
</String literal>
<C++ comment>
 skip escaped character
</C++ comment>
<String literal>
%c
</String literal>