来自fread（）/ calloc的Segfault

Question

我不确定为什么我运行它（使用argv [1]是ppm图像）会导致段错误。有什么想法吗？

unsigned char *image;
char *name;
int sz;

name = argv[1];
FILE *fpt;

fpt = fopen(name,"rb");

fseek(fpt, 0, SEEK_END);
sz = ftell(fpt);
fseek(fpt, 0, SEEK_SET);

image = (unsigned char *) calloc(sz, 1);
fread(image, 1, sz, fpt);