c - fread 返回值 1 字节，即使文件被完全读取

Question

我正在阅读这样的 tarfile：

fh = fopen(filename, "r");

if (fh == NULL) {
    printf("Unable to open %s.\n", filename);
    printf("Exiting.\n");
    return 1;
}

fseek(fh, 0L, SEEK_END);
filesize = ftell(fh);
fseek(fh, 0L, SEEK_SET);

filecontents = (char*)malloc(filesize + 1);     // +1 for null terminator

byteCount = fread(filecontents, filesize, 1, fh);
filecontents[filesize] = 0; 

fclose(fh);

if (byteCount != filesize) {
    printf("Error reading %s.\n", filename);
    printf("Expected filesize: %ld bytes.\n", filesize);
    printf("Bytes read: %d bytes.\n", byteCount);
}

然后我继续解码 tarfile 的内容并提取其中存储的文件。一切正常，文件被提取得很好，但fread()返回1而不是filesize. 我得到的输出是：

Error reading readme.tar.
Expected filesize: 10240 bytes.
Bytes read: 1 bytes.

根据CPP Reference onfread，返回值应该是读取的字节数。

Answer 1

试试这个：

//byteCount = fread(filecontents, filesize, 1, fh);
byteCount = fread(filecontents, 1, filesize, fh);