警告：格式'％d'期望类型'int'，但参数4的类型为'size_t'

Question

我跟着一些类似的帖子来修改代码，但是警告仍然生成。

$ g++ ncfile.c -o ncfile -g -lnetcdf 

ncfile.c: In function ‘int main(int, char**)’: 
ncfile.c:363: warning: format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’ 
ncfile.c:363: warning: format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’ 
ncfile.c:364: warning: format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’ 
ncfile.c:364: warning: format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’ 

在周围线363和364块：

for(i = 0; i < ndimsp; i++) { 
    char * temp_name; 
    size_t temp_len; 
    temp_name = (char *)malloc(sizeof(char) * 20); 
    nc_inq_dim(cid, dimids[i], temp_name, &temp_len); 
    dimlens[i] = temp_len; 
    if(dimids[i] == unlimdimidp) printf("\t\t%d %s \tlength: %d (UNLIMITED)\n", i, temp_name, temp_len); 
    else printf("\t\t%d %s \tlength: %d\n", i, temp_name, temp_len); 
    total_records *= temp_len; 
    free(temp_name); 
    } 

我应该摆脱警告。它对结果有害吗？

感谢，

迈克尔

Answer 1

尝试使用z修饰符。基本上％zu为size_t值。

这将是结果：

printf("\t\t%d %s \tlength: %zu\n", i, temp_name, temp_len); 

看看这个问题：

How can one print a size_t variable portably using the printf family?