警告：格式'％d'期望類型'int'，但參數4的類型爲'size_t'

Question

我跟着一些類似的帖子來修改代碼，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’ 

在周圍線363和364塊：

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); 
    } 

我應該擺脫警告。它對結果有害嗎？

感謝，

邁克爾

Answer 1

嘗試使用z修飾符。基本上％zu爲size_t值。

這將是結果：

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

看看這個問題：

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