C语言经典算法之底层编程：C标志符命名源程序 include, 源程序, C语言, 经典, 命名

苹果也疯狂

/* C标志符命名源程序*/


#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <malloc.h>
char* IsLegal(char* CheckWord);
char* ErrorMessages[]={ /*错误信息列表*/
                            "无错误！",
                            "1  首字符只能是字母或下划线！",
                            "2  常、变量只能由字母、下划线和数字构成！",
                            "3  常、变量标识不能用Ｃ语言关键字！",
                            "4  常、变量标识不能用Ｃ语言函数！",
                            "内存不够！"
};
void main(void)
{
char *Prompt="C语言标志符的命名要遵守以下原则:";
char *TestWord;
int   i;
TestWord = (char *)malloc( sizeof(char)*32 ); /*TestWord存放用户输入*/
  if(!TestWord )
   return;
  /*显示部分提示信息*/
puts(Prompt);
for( i=1 ;i<=4;i++){
   puts( ErrorMessages );
  }
puts("");
while(1){
   printf("\n\n请输入一个标志符(大写的Q退出) :");/*提示*/
   scanf("%s",TestWord);                   /*得到用户输入*/
   if( (toupper)(TestWord[0])=='Q' )
     break;/*循环出口*/
   printf("\n%s  %s",TestWord,IsLegal(TestWord)); /*判定标志符的合法性*/
  }
free( TestWord );
}
/*此函数检验标志符命名的合法性*/
char* IsLegal(char* CheckWord)
{
char*KeyWords[]={"auto","break","case","char","continue","const","default",
                     "do","double","else","enum","extern","float","for","goto",
                      "if","int","long","noalias","register","return","short",
                     "signed","sizeof","static","struct","switch","typedef",
                     "union","unsigned","void","volatile","while","defined",
                     "define","undef","include","ifdef","ifndef","endif","line",
                      "error","elif","pragma"};/*C关键字列表*/
char*Functions[]={"close","creat","eof","fclose","fcloseall","feof","fopen",
                            "ferror","fgetchar","fgets","fprintf","fputc","fputchar",
                            "fseek","get","putch","putc","printf","open","putchar",
                            "puts","read","scanf","abs","acos","asin","math","atan",
                            "atan2","atof","atoi","atol","ceil","dos","cosh","ecvt",
                            "exp","fabs","floor","fmod","frexp","itoa","labs","ldexp",
                            "log","log10","modf","pow","rand","sin","sqrt","srand",
                            "strtod","strlol","tan","tanh","ultoa","memset","strcpy",
                            "struct","strchr","strcmp","calloc","isalnum","isalpha",
                            "toascii","tolower","tollpper","exit"};/*C主要函数列表*/


char* Others="_";/*'_'也可以用于关键字,但我们不推荐您使用!*/
  intWordLength,i;
char* WordTemp;
WordTemp = (char*)malloc( 32 *sizeof(char ) );
  if(!WordTemp ) return ErrorMessages[5];
WordLength=strlen(CheckWord);
  /*检查标志符命名原则1*/
if((isalpha(CheckWord[0])==0)&&(CheckWord[0]!=Others[0]))
         returnErrorMessages[1];
  /*检查标志符命名原则2*/
for(i=0;i<WordLength;i++)
   if((isalnum(CheckWord)==0)&&(CheckWord!=Others[0]))
     return ErrorMessages[2];
  /*检查标志符命名原则3*/
for(i=0;i<44;i++)
  {
   if(!strcmp(CheckWord,KeyWords))
     return ErrorMessages[3];
  }
i=0;
for(i=0;i<69;i++) /*检查标志符命名原则4*/
  {
   if(!strcmp(CheckWord,Functions))
     return ErrorMessages[4];
  }
free(WordTemp);
return ErrorMessages[0];
}