krx12300.c

来自「answer of the c programming language sec」· C语言 代码 · 共 84 行

/******************************************************
"Write a program to remove all comments from a C program. 
Don't forget to handle quoted strings and character 
constants properly. C comments do not nest."

Author: Rick Dearman ([e-mail]) 
******************************************************/

#include <stdio.h>

#define MAXLINE 1000 /* max input line size */
char line[MAXLINE]; /*current input line*/

int getline(void);  /* taken from the KnR book. */


int
main()
{
  int in_comment,len;
  int in_quote;
  int t;
  
  in_comment = in_quote = t = 0;
  while ((len = getline()) > 0 )
    {
      t=0;
      while(t < len)
        {
	  if( line[t] == '"')
		in_quote = 1;

	  if( ! in_quote )
	  {
          	if( line[t] == '/' && line[t+1] == '*')
            	{
              		t=t+2;
              		in_comment = 1;
            	}
          	if( line[t] == '*' && line[t+1] == '/')
            	{
              		t=t+2;
              		in_comment = 0;
            	}
          	if(in_comment == 1)
           	 {
              		t++;
            	}
          	else
            	{
              		printf ("%c", line[t]);
              		t++;
            	}
	  } 
	  else
	  {
              printf ("%c", line[t]);
              t++;
	  }
        }
    }
  return 0;
}


/* getline: specialized version */
int getline(void)
{
  int c, i;
  extern char line[];
  
  for ( i=0;i<MAXLINE-1 && ( c=getchar()) != EOF && c != '\n'; ++i)
    line[i] = c;
  if(c == '\n') 
    {
      line[i] = c;
      ++i;
    }
  line[i] = '\0';
  return i;

}