只是使用
ctype.h提供的函数的算法草图：
#include
void remove_punct_and_make_lower_case(char *p)
{
char *src = p, *dst = p;
while (*src)
{
if (ispunct((unsigned char)*src))
{
/* Skip this character */
src++;
}
else if (isupper((unsigned char)*src))
{
/* Make it lowercase */
*dst++ = tolower((unsigned char)*src);
src++;
}
else if (src == dst)
{
/* Increment both pointers without copying */
src++;
dst++;
}
else
{
/* Copy character */
*dst++ = *src++;
}
}
*dst = 0;
}
标准警告适用：完全未经测试;改进和优化留给读者作为练习.