The prototype `size_t fread(void* restrict ptr, size_t size, size_t nmemb, FILE* restrict stream);` reads `size * nmemb` bytes from the stream’s current file position into memory. A successful call advances that position; a return value smaller than the requested amount signals an error or incomplete operation. section 14.4
Use fread for binary data when these conditions matter:
- Open the stream in binary mode so bytes are read without external-to-internal representation or end-of-line translation. section 14.4
- Treat the stream as having a current file position; combine fread with fseek and ftell to move through a file. section 14.4
- Check the return value rather than assuming that the complete requested amount was read. section 14.4 section 14.6
1 size_t fread(void* restrict ptr, size_t size, size_t nmemb,
2 FILE* restrict stream);
3 size_t fwrite(void const*restrict ptr, size_t size, size_t nmemb,
4 FILE* restrict stream);
5 int fseek(FILE* stream, long int offset, int whence);
6 long int ftell(FILE* stream);
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Compare fread with fwrite, fseek, and ftell through their declarations and parameter types. section 14.4
