从文件读取分段错误

Question

我一直在尝试文件读写功能，遇到了分段错误。它似乎与从文件中读取有关。下面是我写的代码。

The code I wrote is given below:
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <errno.h>

    int main(int argc, char *argv[]){

    //char name[10];
    //strcpy(name, "George");
    //printf("%s\n", name);

    //if(argc == 2){

    //char *myname = "George";

        FILE *file = fopen("Readmystuff" , "rt");//fopen(argv[1],"rt");

        if(file == NULL)
            printf("Could not open file: %s\n", strerror(errno));

        char *str, *cr;
        int maxsize = 200;

        cr = fgets(str, maxsize, file); 

        int fcl = fclose(file); 
    
        printf("\n");   

        int strl = strlen(str);

        if(fcl == 0)
            printf("File closed succesfully\ncr: %c\nstr: %s\nTotal string size - 1 (for null): %i\n", *cr, str, strl);
        else
            printf("File did not close");
    //}
    //else
        //printf("There must be one argument, argv[1] = the filename, for the code to work\n");
    
    return 0;
}

Answer 1

 char *str, *cr;

 /* ... */

 cr = fgets(str, maxsize, file); 

您的

str

指针未初始化，其值不确定。您正在写入无效对象。要么定义一个足够大小的数组，要么使用

malloc

来分配一个。