std::rewind(3)

πŸ“¦ version 2024.07.05, in nixpkgs unstable, opensuse-leap 16.0

✨ std::rewind(3) β€” std::rewind ✨

okay so this is the std::rewind(3) manual page, bestie, and it's literally all about sending a file stream back to the start πŸ’…


🌸 NAME 🌸

std::rewind β€” std::rewind

fr fr, that's the name and that's the vibe.


πŸŽ€ Synopsis πŸŽ€

Defined in header <cstdio>:

void rewind( std::FILE* stream );

Moves the file position indicator to the beginning of the given file stream.

The function is equivalent to std::fseek(stream, 0, SEEK_SET);, except that end-of-file and error indicators are cleared.

The function drops any effects from previous calls to ungetc.


πŸ¦‹ Parameters πŸ¦‹

  • stream β€” file stream to modify

⭐ Return value ⭐

(none)

no return value, no drama, periodt πŸ’–


πŸ’œ Example πŸ’œ

// Run this code

#include <array>
#include <cstdio>

int main()
{
    std::FILE* f = std::fopen("file.txt", "w");
    for (char ch = '0'; ch <= '9'; ch++)
        std::fputc(ch, f);
    std::fclose(f);

    std::array<char, 20> str;
    std::FILE* f2 = std::fopen("file.txt", "r");

    const unsigned size1 = std::fread(str.data(), 1, str.size(), f2);
    std::puts(str.data());
    std::printf("size1 = %u\n", size1);

    std::rewind(f2);

    const unsigned size2 = std::fread(str.data(), 1, str.size(), f2);
    std::puts(str.data());
    std::printf("size2 = %u", size2);

    std::fclose(f2);
}

Output:

0123456789
size1 = 10
0123456789
size2 = 10

🌈 See also 🌈

  • fseek β€” moves the file position indicator to a specific location in a file (function)
  • C documentation for rewind

source: http://cppreference.com β€” version/date: 2024.06.10 β€” okay bye bestie, go rewind something iconic πŸ«ΆπŸ’–

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