以下两则代码均是在向论坛上的高手们学习之后模仿出的结果,而自己之前写的那叫个臭呀!
代码1
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/**//*
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* 用状态机实现对代码中注释的清除.
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*/
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#include <stdio.h>
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#include <string.h>
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#define SCREEN
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void initialize_fsm(char fsm[7][256]);
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int main()
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{
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int ch , temp = 0 ;
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int state = 0;
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char fsm[7][256];
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FILE *pfin ;
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if ((pfin = fopen("sweep-comments.txt","r")) == NULL)
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{
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printf("can not open the file");
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exit(0);
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}
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#ifdef SCREEN
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#define OUT stdout
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#else
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FILE *pfout;
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pfout = fopen("result.txt","w");
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#define OUT pfout
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#endif
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initialize_fsm(fsm);
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#pragma region FSM /**////尝试#pragma region功能. Visual C++ 2005
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while ((ch = fgetc(pfin)) != EOF)
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{
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state = fsm[state][ch];
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if ( state != 2 && ch !='*' && temp == '/')
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fputc(temp,OUT);
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temp = ch;
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switch(state)
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{
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/**//*0,5,6执行同一个动作*/
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case 5:
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case 6:
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case 0:
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fputc(ch,OUT);
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break;
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case 7:
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state = 0;
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break;
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}
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if(state != 1)
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temp=0;
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}
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#pragma endregion
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}
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void initialize_fsm(char fsm[7][256])
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{
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int lenth = sizeof(char)*256;
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memset(fsm[0],0,lenth);
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memset(fsm[1],0,lenth);
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memset(fsm[2],2,lenth);
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memset(fsm[3],3,lenth);
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memset(fsm[4],3,lenth);
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memset(fsm[5],5,lenth);
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memset(fsm[6],5,lenth);
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fsm[0]['"'] = 5;
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fsm[0]['/'] = 1;
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fsm[1]['/'] = 2;
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fsm[1]['*'] = 3;
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fsm[2]['\n'] = 0;
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fsm[3]['*'] = 4;
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fsm[4]['/'] = 7;
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fsm[5]['\\'] = 6;
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fsm[5]['"'] = 0;
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}
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代码2
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%
{
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/**//*
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*用lex实现清除代码注释
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*/
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void comment(int style);
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void string_constant();
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const int singalline =0, multiline =1;
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%}
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%%
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"/*"
{comment(multiline );}
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"//"
{comment(singalline);}
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"\"" {string_constant();}
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.|\n
{fprintf(yyout,"%c",*yytext);}
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%%
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int main(int argc,char *argv[])
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{
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FILE *pfin ,*pfout;
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if ((pfin = fopen (argv[1],"r")) ==NULL)
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{
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printf("can not open the file\n");
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exit (1);
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}
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pfout = fopen("output.txt","w");
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yyin = pfin;
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yyout = pfout;
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yylex();
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return 0;
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}
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void string_constant()
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{
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int ch ;
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fprintf(yyout,"%c",*yytext);
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while ( (ch = input()) != EOF)
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{
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if (ch == '\\')
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{
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fprintf(yyout,"%c",ch);
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ch = input();
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fprintf(yyout,"%c",ch);
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continue;
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}
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if (ch == '\"')
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{
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fprintf(yyout,"%c",ch);
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break;
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}
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fprintf(yyout,"%c",ch);
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}
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}
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void comment(int style)
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{
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int ch , prev=0;
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if (style == multiline)
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{
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while ( (ch = input()) != EOF )
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{
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if (prev == '*' && ch == '/')
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return ;
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prev = ch;
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}
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return ;
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}
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else
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{
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while ( (ch = input()) != EOF )
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{
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if (ch == '\n')
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{
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fprintf(yyout,"%c",'\n');
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return ;
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}
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}
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}
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}
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int yywrap()
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{
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return 1;
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}
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posted on 2009-05-07 14:21
zhaoyg 阅读(643)
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