strdup字符复制，strtok_r分割字符串，strchr查找字符等的用法

strdup字符复制，strtok_r分割字符串，strchr查找字符等的用法

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>char *input = "My test string";int main(int argc, char *argv[]){    char *token=NULL, *arg=NULL, *saveptr=NULL;    printf("Input stirng: %s, length is %d\n", input, (unsigned int)strlen(input));    arg = strdup(input);    if (strchr(arg, ' ') != NULL)    {        token = strtok_r(arg, " ", &saveptr);        if (token == NULL)            return 0;        printf("token is %s\n", token);        while ((token = strtok_r(NULL, " ", &saveptr)) != NULL)        {             printf("token is %s\n", token);        }    }    return 0;}