Reading members out of a ZIP archive, to a file. More...

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <zlib.h>
#include "nilorea/n_log.h"
#include "nilorea/n_zip.h"

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Data Structures
struct	ZIP_SINK
	where unpacked bytes go: a file, or a buffer in memory More...

Macros
#define	N_ZIP_CHUNK 262144
	the pieces a member is read and written in
#define	N_ZIP_TAIL (22 + 65535)
	how much of an archive's end is searched for its end record: the record and the longest comment it may carry

Functions
static unsigned	le16 (const unsigned char *p)
	helper: a little endian 16 bit value
static uint32_t	le32 (const unsigned char *p)
	helper: a little endian 32 bit value
int	n_zip_extract (const char path, const char name, const char *out)
	write a member out to a file, checking its CRC-32
int	n_zip_find (const char path, const char name, N_ZIP_MEMBER *member)
	find a member by its full name in an archive's central directory
int	n_zip_find_ending (const char path, const char ending, char *name, size_t name_len)
	find the first member whose name ends with a given text, as a PyTorch checkpoint's "archive/data.pkl" whose folder name varies
int	n_zip_read (const char path, const char name, size_t max_size, unsigned char *data, size_t len)
	read a member into memory, checking its CRC-32
static int	seek_to (FILE *f, uint64_t at)
	helper: seek to a 64 bit offset where the platform's fseek takes a long
static int	sink_put (ZIP_SINK sink, const unsigned char data, size_t len)
	put unpacked bytes where they go
static int	zip_scan (const char path, const char name, int ending, N_ZIP_MEMBER member, char found_name, size_t found_len)
	find a member by its whole name, or by how its name ends
static int	zip_unpack (const char path, const char name, const N_ZIP_MEMBER member, ZIP_SINK sink)
	unpack a member into a sink, checking its size and CRC-32

Detailed Description

Reading members out of a ZIP archive, to a file.

Author: Castagnier Mickael

Version: 1.0

Date: 28/09/2026

Definition in file n_zip.c.

Data Structure Documentation

◆ ZIP_SINK

struct ZIP_SINK

where unpacked bytes go: a file, or a buffer in memory

Definition at line 162 of file n_zip.c.

Collaboration diagram for ZIP_SINK:

Data Fields
unsigned char *	buffer	the buffer, allocated to the member's size
FILE *	file	the file, or NULL
size_t	size	its size
size_t	used	how much of it is written

Macro Definition Documentation

◆ N_ZIP_CHUNK

#define N_ZIP_CHUNK 262144

the pieces a member is read and written in

Definition at line 42 of file n_zip.c.

Referenced by zip_unpack().

◆ N_ZIP_TAIL

#define N_ZIP_TAIL (22 + 65535)

how much of an archive's end is searched for its end record: the record and the longest comment it may carry

Definition at line 40 of file n_zip.c.

Referenced by zip_scan().

Function Documentation

◆ le16()

unsigned le16 ( const unsigned char * p )

static

helper: a little endian 16 bit value

Definition at line 45 of file n_zip.c.

Referenced by zip_scan(), and zip_unpack().

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◆ le32()

uint32_t le32 ( const unsigned char * p )

static

helper: a little endian 32 bit value

Examples: ex_icc.c.

Definition at line 49 of file n_zip.c.

Referenced by make_tiff(), make_webp(), zip_scan(), and zip_unpack().

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◆ seek_to()

int seek_to	(	FILE *	f,
		uint64_t	at )

static

helper: seek to a 64 bit offset where the platform's fseek takes a long

Definition at line 54 of file n_zip.c.

Referenced by zip_scan(), and zip_unpack().

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◆ sink_put()

int sink_put	(	ZIP_SINK *	sink,
		const unsigned char *	data,
		size_t	len )

static

put unpacked bytes where they go

Parameters

sink	the destination
data	the bytes
len	how many

Returns: 0, or -1 when the file refused them or the buffer is full

Definition at line 178 of file n_zip.c.

References ZIP_SINK::buffer, ZIP_SINK::file, ZIP_SINK::size, and ZIP_SINK::used.

Referenced by zip_unpack().

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◆ zip_scan()

int zip_scan	(	const char *	path,
		const char *	name,
		int	ending,
		N_ZIP_MEMBER *	member,
		char *	found_name,
		size_t	found_len )

static

find a member by its whole name, or by how its name ends

Parameters

path	the archive
name	the name, or its ending
ending	non-zero to match the ending only
member	receives what it is, may be NULL
found_name	receives the whole name when matching an ending, may be NULL
found_len	size of found_name