Question

我的代码如下：

#include <curl/curl.h>
struct callback_data {
         FILE *output;
         char *path; //to specify the entire path
         char *fname; //Full file name of current download
         char *msg; //message for display
};              

static long file_is_comming(struct curl_fileinfo *finfo, struct callback_data *data, int remains);

static long file_is_downloaded(struct callback_data *data);

static size_t write_it(char *buff, size_t size, size_t nmemb,
                       struct callback_data *data);

static long file_is_comming(struct curl_fileinfo *finfo, struct callback_data *data, int remains)
{
         printf("%3d %40s %10luB ", remains, finfo->filename, (unsigned long)finfo->size);

         printf("dest path = %s \n", data->path);
         if(finfo->filetype == CURLFILETYPE_FILE) {

                 data->fname = (char *)malloc( (sizeof(char *)) *
                                 (strlen(finfo->filename) + strlen(data->path)+1));

                 sprintf(data->fname, "%s%s", data->path, finfo->filename);
                 data->output = fopen(data->fname, "w");
         printf("dest file name = %s \n", data->fname);

                 if(!data->output) {
                         return CURL_CHUNK_BGN_FUNC_FAIL;
                 }
         }

         return CURL_CHUNK_BGN_FUNC_OK;
}

警告是：

warning: 'struct curl_fileinfo' declared inside parameter list
warning: 'struct curl_fileinfo' declared inside parameter list
utils-curl.h:15: warning: its scope is only this definition or declaration, which is probably not what you want
utils-curl.c:3: warning: 'struct curl_fileinfo' declared inside parameter list
utils-curl.c:4: error: conflicting types for 'file_is_comming'
utils-curl.h:15: error: previous declaration of 'file_is_comming' was here

Answer 1

在函数定义中使用指针之前，您需要包含正确的标头或转发声明struct curl_fileinfo。

Answer 2

我认为您在以下几行中尝试做的可能不是您想要做的！

10                 data->fname = (char *)malloc( (sizeof(char *)) *
11                                 (strlen(finfo->filename) + strlen(data->path)+1));

我想你想做

10                 data->fname = (char *)malloc( (sizeof(char)) *
11                                 (strlen(finfo->filename) + strlen(data->path)+1));

sizeof(char)和不 sizeof(char *)

您必须输入sizeof()的输出到int，因为sizeof()会返回size_t而不是int。

OTOH，在使用malloc'ed内存之前，必须检查malloc()是否成功！

除了警告之外，我认为您还应该调查以下错误：

    utils-curl.c:4: error: conflicting types for 'file_is_comming'
    utils-curl.h:15: error: previous declaration of 'file_is_comming' was here

警告：在参数列表中声明'struct curl_fileinfo'

2 个答案: