libqcow(3)

💖 libqcow — bestie's guide to the QEMU Copy-On-Write image format 💖

okay so you found libqcow(3) and you're like "what is this" — bestie, this is the library that lets you access the QEMU Copy-On-Write (QCOW) image file format. yes. the whole thing. it's a C library, it lives in libqcow.h, and it's genuinely iconic. let's get into it 🫶

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✨ SYNOPSIS ✨

first things first, the include. literally one line, you got this:

#include <libqcow.h>

🌸 Support functions

const char *
libqcow_get_version(void);

int
libqcow_get_access_flags_read(void);

int
libqcow_get_access_flags_read_write(void);

int
libqcow_get_access_flags_write(void);

int
libqcow_get_codepage(int *codepage, libqcow_error_t **error);

int
libqcow_set_codepage(int codepage, libqcow_error_t **error);

int
libqcow_check_file_signature(const char *filename,
    libqcow_error_t **error);

available when compiled with wide character string support:

int
libqcow_check_file_signature_wide(const wchar_t *filename,
    libqcow_error_t **error);

available when compiled with libbfio support:

int
libqcow_check_file_signature_file_io_handle(libbfio_handle_t *bfio_handle,
    libqcow_error_t **error);

🎀 Notify functions

void
libqcow_notify_set_verbose(int verbose);

int
libqcow_notify_set_stream(FILE *stream, libqcow_error_t **error);

int
libqcow_notify_stream_open(const char *filename,
    libqcow_error_t **error);

int
libqcow_notify_stream_close(libqcow_error_t **error);

🦋 Error functions

void
libqcow_error_free(libqcow_error_t **error);

int
libqcow_error_fprint(libqcow_error_t *error, FILE *stream);

int
libqcow_error_sprint(libqcow_error_t *error, char *string, size_t size);

int
libqcow_error_backtrace_fprint(libqcow_error_t *error, FILE *stream);

int
libqcow_error_backtrace_sprint(libqcow_error_t *error, char *string,
    size_t size);

👑 File functions

int
libqcow_file_initialize(libqcow_file_t **file, libqcow_error_t **error);

int
libqcow_file_free(libqcow_file_t **file, libqcow_error_t **error);

int
libqcow_file_signal_abort(libqcow_file_t *file,
    libqcow_error_t **error);

int
libqcow_file_open(libqcow_file_t *file, const char *filename,
    int access_flags, libqcow_error_t **error);

int
libqcow_file_close(libqcow_file_t *file, libqcow_error_t **error);

int
libqcow_file_is_locked(libqcow_file_t *file, libqcow_error_t **error);

ssize_t
libqcow_file_read_buffer(libqcow_file_t *file, void *buffer,
    size_t buffer_size, libqcow_error_t **error);

ssize_t
libqcow_file_read_buffer_at_offset(libqcow_file_t *file, void *buffer,
    size_t buffer_size, off64_t offset, libqcow_error_t **error);

off64_t
libqcow_file_seek_offset(libqcow_file_t *file, off64_t offset,
    int whence, libqcow_error_t **error);

int
libqcow_file_get_offset(libqcow_file_t *file, off64_t *offset,
    libqcow_error_t **error);

int
libqcow_file_set_parent_file(libqcow_file_t *file,
    libqcow_file_t *parent_file, libqcow_error_t **error);

int
libqcow_file_get_format_version(libqcow_file_t *file,
    uint32_t *format_version, libqcow_error_t **error);

int
libqcow_file_get_encryption_method(libqcow_file_t *file,
    uint32_t *encryption_method, libqcow_error_t **error);

int
libqcow_file_set_keys(libqcow_file_t *file, const uint8_t *key,
    size_t key_size, libqcow_error_t **error);

int
libqcow_file_set_utf8_password(libqcow_file_t *file,
    const uint8_t *utf8_string, size_t utf8_string_length,
    libqcow_error_t **error);

int
libqcow_file_set_utf16_password(libqcow_file_t *file,
    const uint16_t *utf16_string, size_t utf16_string_length,
    libqcow_error_t **error);

int
libqcow_file_get_media_size(libqcow_file_t *file, size64_t *media_size,
    libqcow_error_t **error);

int
libqcow_file_get_utf8_backing_filename_size(libqcow_file_t *file,
    size_t *utf8_string_size, libqcow_error_t **error);

int
libqcow_file_get_utf8_backing_filename(libqcow_file_t *file,
    uint8_t *utf8_string, size_t utf8_string_size,
    libqcow_error_t **error);

int
libqcow_file_get_utf16_backing_filename_size(libqcow_file_t *file,
    size_t *utf16_string_size, libqcow_error_t **error);

int
libqcow_file_get_utf16_backing_filename(libqcow_file_t *file,
    uint16_t *utf16_string, size_t utf16_string_size,
    libqcow_error_t **error);

int
libqcow_file_get_number_of_snapshots(libqcow_file_t *file,
    int *number_of_snapshots, libqcow_error_t **error);

available when compiled with wide character string support:

int
libqcow_file_open_wide(libqcow_file_t *file, const wchar_t *filename,
    int access_flags, libqcow_error_t **error);

available when compiled with libbfio support:

int
libqcow_file_open_file_io_handle(libqcow_file_t *file,
    libbfio_handle_t *file_io_handle, int access_flags,
    libqcow_error_t **error);

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💅 DESCRIPTION 💅

so basically: the libqcow_get_version() function is used to retrieve the library version. that's the vibe. that's what it does. no cap.

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🌈 RETURN VALUES 🌈

most of these functions return NULL or -1 on error — depends on the return type, so like, check what you're calling bestie. for the actual return values, go look at libqcow.h (iykyk).

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🍓 ENVIRONMENT 🍓

None

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🧚 FILES 🧚

None

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💜 NOTES 💜

libqcow can be compiled with wide character support (wchar_t). slay.

to compile libqcow with wide character support, use:

./configure --enable-wide-character-type=yes

or define:

_UNICODE

or:

UNICODE

during compilation. pick your fighter ✨

LIBQCOW_WIDE_CHARACTER_TYPE in libqcow/features.h can be used to figure out whether libqcow was compiled with wide character support. so like, vibe check the build flags before you assume anything 💅

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😭 BUGS 😭

please report bugs of any kind on the project issue tracker:

https://github.com/libyal/libqcow/issues

they want to hear from you fr fr.

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🎀 AUTHOR 🎀

these man pages are generated from libqcow.h. iconic behavior honestly.

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⭐ COPYRIGHT ⭐

Copyright (C) 2010-2024, Joachim Metz <joachim.metz@gmail.com>.

this is free software; see the source for copying conditions. there is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. so like, no promises bestie, it's giving "as-is" energy 💀

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🌸 SEE ALSO 🌸

• the libqcow.h include file

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okay that's the whole page 🫶 go forth and read your QCOW images, main character energy only

this has been libqcow, from the Library Functions Manual, and it's dated December 12, 2020 — version libqcow(3), periodt 💅✨