常用的字符串处理模型

#include <stdio.h>
#include <string.h>
#include <ctype.h>

/*strstr_while字串模型*/
int Search_count(char *p, char *str)
{
	int ncount = 0;

	if (NULL == p || NULL == str)
	{
		printf("func Search_count() err: %d (NULL == p || NULL = str)\n", ncount);
		return -1;
	}
	else
	{
		while (p = strstr(p, str))
		{
			ncount++;
			p += sizeof(str);

			if (*p == ‘\0‘)
				break;
		}
		return ncount;
	}
}

/*两头堵字串模型1*/
int NoSpaceLen1(char *str, char *newStr)
{
	int i = 0, j = strlen(str) - 1;
	int ncount = 0;

	if (NULL == str || NULL == newStr)
	{
		printf("func NoSpaceLen1() err:-1 (NULL == str)\n");
		return -1;
	}

	while (isspace(str[i]) && str[i] != ‘\0‘)
		i++;
	while (isspace(str[j]) && str[j] != ‘\0‘)
		j--;

	ncount = j - i + 1;
	strncpy(newStr, str+i, ncount);  //将两头去除空格后的子串保存至newStr中
	newStr[ncount] = ‘\0‘;          //此处需要特别注意，不能忘记加字串结尾标志

	return ncount;
}

/*两头堵字串模型2*/
//此函数需要将去除空格后的子串保存到原str中，所以要求其所指向的内存空间可以被修改才可以
int NoSpaceLen2(char *str)
{
	int i = 0, j = strlen(str)-1;
	int ncount = 0;

	if (NULL == str)
	{
		printf("func NoSpaceLen2() err: -1 (NULL == str)!\n");
		return -1;
	}
	else
	{
		while (isspace(str[i]) && str[i] != ‘\0‘)
			i++;
		while (isspace(str[j]) && str[j] != ‘\0‘)
			j--;

		ncount = j - i + 1;
		strncpy(str, str+i, ncount);  //将两头去除空格后的子串保存至原str中
		str[ncount] = ‘\0‘;           //此处需要特别注意，不能忘记加字串结尾标志

		return ncount;
	}
}

/*字符串反转1*/
//此函数需要将反转的字串保存到原str中，所以要求其所指向的内存空间可以被修改才可以
int Inverse(char *str)
{
	int len = strlen(str);
	char *p1, *p2;
	char temp;

	if (NULL == str)
	{
		printf("func Inverse() err: -1 (NULL == str)!\n");
		return -1;
	}
	else
	{
		p1 = str;
		p2 = str + len -1;

		while (p1 < p2)
		{
			temp = *p1;
			*p1 = *p2;
			*p2 = temp;
			p1++;
			p2--;
		}

		return 1;
	}
}

int main()
{
	char *p = "54abcd12133abcd22abcd333333abcd";
	char *s = "";
	char *str = "    sdfssf   ";
	char newStr[1024] = { 0 };
	char s1[20] = "   99 ds  ";
	char s2[20] = "  I love you !  ";

	if (Search_count(p, s) != -1)
		printf("字符串%s中含有%d个字串%s！\n\n", p, Search_count(p, s), s);

	if (NoSpaceLen1(str, newStr) != -1)
		printf("该字串去除前后空格后的字符数： ncount = %d  子串：%s\n\n", NoSpaceLen1(str, newStr), newStr);

	if (NoSpaceLen2(s1) != -1)
		printf("该字串去除前后空格后的字符数： ncount = %d  字串：%s\n\n", NoSpaceLen2(s1), s1);

	Inverse(s2);
	printf("%s\n%d\n", s2);

	return 0;
}