清除字符串开头结尾除空白
修改原字符串
不能清除全角字符

/* * 清除字符串开始结尾处的空白 * 修改原字符串 * */static char* trim(char*str){ char* p1 = str,*p2 = NULL,*p3 = NULL; int flag = 0; while(*(p1) != '\0'){ if(isspace(*p1)){ if(p3 == NULL) p3 = p2 == NULL?p1:p2;//标记结尾空白 if(0 == flag) {//标记开头为空白 flag = 1; p2 = p1; }else if(2 == flag){//中间空白 *(p2++) = *p1; } }else { if(1 == flag || flag == 2){//开头空白结束标志 *(p2++) = *p1; flag = 2; }else flag = -1;//开头无空白 p3 = NULL;//清除结尾空白 } p1++; } //标记结尾 if(p3 != NULL) *p3 = '\0'; else if(p2 != NULL) *p2 = '\0'; return str;}