Created
June 6, 2013 15:13
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一个简单的正则表达式匹配器,摘自《代码之美》第一章
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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 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' && (regexp[0]=='.' || regexp[0]==*text)) | |
return matchhere(regexp+1, text+1); | |
return 0; | |
} | |
int matchstar(char c, char *regexp, char *text) | |
{ | |
do { | |
if (matchhere(regexp, text)) | |
return 1; | |
} while (*text != '\0' && (*text++ == c || c == '.')); | |
return 0; | |
} |
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