正则表达式c语言经典实现
/*
* test.c
*
* Created on: 2012-12-4
* Author: Administrator
*/
#include <stdio.h>
int matchhere(char *,char *);
int matchstar(int c,char *regexp,char *text){
char *t;
for(t = text; *t != '\0' &&(*t == c || c=='.');t++);
do{
if(matchhere(regexp,t))return 1;
}while(t-->text);
return 0;
}
int matchhere(char *regexp, char *text) {
if (regexp[0] == '\0') {
return 1;
}
if (regexp[1] == '*') {
return matchstar(regexp[0], regexp + 2, text);
}
if (regexp[0] == '$' && regexp[1] == '\0') {
return *text == '\0';
}
if((text[0] != '\0')&&(regexp[0]=='.'|| regexp[0]==text[0])) {
return matchhere(regexp+1,text+1);
}
return 0;
}
int match(char *regexp, char *text) {
if (regexp[0] == '^')
return matchhere(regexp + 1, text);
do {
if (matchhere(regexp, text)) {
return 1;
}
} while (*text++ != '\0');
return 0;
}
int main(){
char *regexp = ".*$";
char *text = "123";
if(match(regexp,text)){
puts("ok");
}
return 0;
}
补充：软件开发 , C语言 ,
