C语言 strtok 字符串分割

C语言 strtok 字符串分割

参考：

C++ 字符串分割方法 实现split：http://blog.csdn.net/u012005313/article/details/46483057

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使用函数 strtok 可实现 C 语言环境下的字符串分割

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百度百科：strtok

cstring：strtok

函数：

char * strtok ( char * str, const char * delimiters );

参数：

• str：待分割的字符串
• delimiters：分隔符（字符串中每个字符均为分隔符）

功能：分割字符串

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例程：

#include 
#include 
#include 

int main(int argc, char* argv[]) {
    char str[] = "- This, a sample string.";
    char * pch;
    printf("Splitting string \"%s\" into tokens:\n", str);
    pch = strtok(str, " ,.-");
    while (pch != NULL)
    {
        printf("%s\n", pch);
        pch = strtok(NULL, " ,.-");
    }

    printf("str: %s\n", str);

    system("pause");
    return 0;
}

结果：

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问题1：经过分割后，字符串 str 不再和原先一致

封装了一个函数：

#include 
#include 
#include 

#define IN
#define OUT

typedef struct split {
    char info[1024];
    int num;
    struct split *next;
}SplitInfo;

void GetSplitString(IN char* str, IN char* delim, OUT SplitInfo* splitInfo)
{
    int n = 0;
    char* next = NULL;
    SplitInfo* top = splitInfo;

    char arr[1024];
    strcpy(arr, str);

    next = strtok(arr, delim);
    if (next == NULL) {
        splitInfo->num = 0;
        splitInfo->next = NULL;

        return;
    }

    SplitInfo* in = (SplitInfo*)malloc(sizeof(SplitInfo));
    strcpy(in->info, next);
    in->next = NULL;
    top->next = in;
    top = in;
    n++;

    while (next = strtok(NULL, delim))
    {
        SplitInfo* te = (SplitInfo*)malloc(sizeof(SplitInfo));
        strcpy(te->info, next);
        te->next = NULL;
        top->next = te;
        top = te;
        n++;
    }

    splitInfo->num = n;
}

void SplitFree(SplitInfo* splitInfo) {
    SplitInfo* top = splitInfo->next;
    while (top) {
        SplitInfo* next = top->next;
        free(top);
        top = next;
    }

    splitInfo->next = NULL;
    splitInfo->num = 0;
}

int main(int argc, char* argv[]) {
    char str[] = "- This, a sample string.";
    //char * pch;
    printf("Splitting string \"%s\" into tokens:\n", str);
    //pch = strtok(str, " ,.-");
    //while (pch != NULL)
    //{
    //  printf("%s\n", pch);
    //  pch = strtok(NULL, " ,.-");
    //}

    SplitInfo splitInfo;
    splitInfo.next = NULL;
    GetSplitString(str, " ,.-", &splitInfo);

    SplitInfo* top = &splitInfo;
    for (int i = 0; i < splitInfo.num; i++) {
        top = top->next;
        printf("%s\n", top->info);
    }

    SplitFree(&splitInfo);

    printf("str: %s\n", str);

    // ----

    char str2[] = "Hello World";
    GetSplitString(str2, "Hello World", &splitInfo);

    top = &splitInfo;
    for (int i = 0; i < splitInfo.num; i++) {
        top = top->next;
        printf("%s\n", top->info);
    }

    SplitFree(&splitInfo);

    printf("str2: %s\n", str2);

    system("pause");
    return 0;
}

结果：

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问题2：输入参数 str 应该为数组而非字符串?

参考：C语言中strtok函数进行分割字符串！

但是在封装后的函数中输入字符串同样可以运行，这里还没太搞懂字符串和数组的区别，以及实参和形参的转换，等待以后搞懂

问题3：函数 strtok 是非线程安全的函数？

在 Linux 环境下，可以使用函数 strtok_r 来代替

百度百科：strtok_r