iOS上识别excel表格内容的Demo，可以识别xlsx格式文件的内容

/* zip.c -- IO on .zip files using zlib Version 1.1, February 14h, 2010 part of the MiniZip project Copyright (C) 1998-2010 Gilles Vollant http://www.winimage.com/zLibDll/minizip.html Modifications for Zip64 support Copyright (C) 2009-2010 Mathias Svensson http://result42.com Modifications for AES, PKWARE disk spanning Copyright (C) 2010-2014 Nathan Moinvaziri This program is distributed under the terms of the same license as zlib. See the accompanying LICENSE file for the full text of the license. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> #include "zlib.h" #include "zip.h" #ifdef STDC # include <stddef.h> # include <string.h> # include <stdlib.h> #endif #ifdef NO_ERRNO_H extern int errno; #else # include <errno.h> #endif #ifdef HAVE_AES # define AES_METHOD (99) # define AES_PWVERIFYSIZE (2) # define AES_AUTHCODESIZE (10) # define AES_MAXSALTLENGTH (16) # define AES_VERSION (0x0001) # define AES_ENCRYPTIONMODE (0x03) # include "aes.h" # include "fileenc.h" # include "prng.h" # include "entropy.h" #endif #ifndef NOCRYPT # define INCLUDECRYPTINGCODE_IFCRYPTALLOWED # include "crypt.h" #endif #ifndef local # define local static #endif /* compile with -Dlocal if your debugger can't find static symbols */ #define SIZEDATA_INDATABLOCK (4096 - (4 * 4)) #define DISKHEADERMAGIC (0x08074b50) #define LOCALHEADERMAGIC (0x04034b50) #define CENTRALHEADERMAGIC (0x02014b50) #define ENDHEADERMAGIC (0x06054b50) #define ZIP64ENDHEADERMAGIC (0x06064b50) #define ZIP64ENDLOCHEADERMAGIC (0x07064b50) #define FLAG_LOCALHEADER_OFFSET (0x06) #define CRC_LOCALHEADER_OFFSET (0x0e) #define SIZECENTRALHEADER (0x2e) /* 46 */ #define SIZECENTRALHEADERLOCATOR (0x14) /* 20 */ #define SIZECENTRALDIRITEM (0x2e) #define SIZEZIPLOCALHEADER (0x1e) #ifndef BUFREADCOMMENT # define BUFREADCOMMENT (0x400) #endif #ifndef VERSIONMADEBY # define VERSIONMADEBY (0x0) /* platform dependent */ #endif #ifndef Z_BUFSIZE # define Z_BUFSIZE (64 * 1024) #endif #ifndef Z_MAXFILENAMEINZIP # define Z_MAXFILENAMEINZIP (256) #endif #ifndef ALLOC # define ALLOC(size) (malloc(size)) #endif #ifndef TRYFREE # define TRYFREE(p) {if (p) free(p); } #endif /* NOT sure that this work on ALL platform */ #define MAKEULONG64(a, b) ((ZPOS64_T)(((unsigned long)(a)) | ((ZPOS64_T)((unsigned long)(b))) << 32)) #ifndef DEF_MEM_LEVEL # if MAX_MEM_LEVEL >= 8 # define DEF_MEM_LEVEL 8 # else # define DEF_MEM_LEVEL MAX_MEM_LEVEL # endif #endif const char zip_copyright[] = " zip 1.01 Copyright 1998-2004 Gilles Vollant - http://www.winimage.com/zLibDll"; typedef struct linkedlist_datablock_internal_s { struct linkedlist_datablock_internal_s *next_datablock; uLong avail_in_this_block; uLong filled_in_this_block; uLong unused; /* for future use and alignment */ unsigned char data[SIZEDATA_INDATABLOCK]; } linkedlist_datablock_internal; typedef struct linkedlist_data_s { linkedlist_datablock_internal *first_block; linkedlist_datablock_internal *last_block; } linkedlist_data; typedef struct { z_stream stream; /* zLib stream structure for inflate */ #ifdef HAVE_BZIP2 bz_stream bstream; /* bzLib stream structure for bziped */ #endif #ifdef HAVE_AES fcrypt_ctx aes_ctx; prng_ctx aes_rng[1]; #endif int stream_initialised; /* 1 is stream is initialized */ uInt pos_in_buffered_data; /* last written byte in buffered_data */ ZPOS64_T pos_local_header; /* offset of the local header of the file currently writing */ char *central_header; /* central header data for the current file */ uLong size_centralextra; uLong size_centralheader; /* size of the central header for cur file */ uLong size_centralextrafree; /* Extra bytes allocated to the central header but that are not used */ uLong size_comment; uLong flag; /* flag of the file currently writing */ int method; /* compression method written to file.*/ int compression_method; /* compression method to use */ int raw; /* 1 for directly writing raw data */ Byte buffered_data[Z_BUFSIZE]; /* buffer contain compressed data to be writ*/ uLong dosDate; uLong crc32; int zip64; /* Add ZIP64 extended information in the extra field */ uLong number_disk; /* number of current disk used for spanning ZIP */ ZPOS64_T pos_zip64extrainfo; ZPOS64_T total_compressed; ZPOS64_T total_uncompressed; #ifndef NOCRYPT unsigned long keys[3]; /* keys defining the pseudo-random sequence */ const unsigned long *pcrc_32_tab; int crypt_header_size; #endif } curfile64_info; typedef struct { zlib_filefunc64_32_def z_filefunc; voidpf filestream; /* io structure of the zipfile */ voidpf filestream_with_CD; /* io structure of the zipfile with the central dir */ linkedlist_data central_dir; /* datablock with central dir in construction*/ int in_opened_file_inzip; /* 1 if a file in the zip is currently writ.*/ int append; /* append mode */ curfile64_info ci; /* info on the file currently writing */ ZPOS64_T begin_pos; /* position of the beginning of the zipfile */ ZPOS64_T add_position_when_writting_offset; ZPOS64_T number_entry; ZPOS64_T disk_size; /* size of each disk */ uLong number_disk; /* number of the current disk, used for spanning ZIP */ uLong number_disk_with_CD; /* number the the disk with central dir, used for spanning ZIP */ #ifndef NO_ADDFILEINEXISTINGZIP char *globalcomment; #endif } zip64_internal; /* Allocate a new data block */ local linkedlist_datablock_internal *allocate_new_datablock OF(()); local linkedlist_datablock_internal *allocate_new_datablock() { linkedlist_datablock_internal *ldi; ldi = (linkedlist_datablock_internal *)ALLOC(sizeof(linkedlist_datablock_internal)); if (ldi != NULL) { ldi->next_datablock = NULL; ldi->filled_in_this_block = 0; ldi->avail_in_this_block = SIZEDATA_INDATABLOCK; } return ldi; } /* Free data block in linked list */ local void free_datablock OF((linkedlist_datablock_internal * ldi)); local void free_datablock(linkedlist_datablock_internal *ldi) { while (ldi != NULL) { linkedlist_datablock_internal *ldinext = ldi->next_datablock; TRYFREE(ldi); ldi = ldinext; } } /* Initialize linked list */ local void init_linkedlist OF((linkedlist_data * ll)); local void init_linkedlist(linkedlist_data *ll) { ll->first_block = ll->last_block = NULL; } /* Free entire linked list and all data blocks */ local void free_linkedlist OF((linkedlist_data * ll)); local void free_linkedlist(linkedlist_data *ll) { free_datablock(ll->first_block); ll->first_block = ll->last_block = NULL; } /* Add data to linked list data block */ local int add_data_in_datablock OF((linkedlist_data * ll, const void *buf, uLong len)); local int add_data_in_datablock(linkedlist_data *ll, const void *buf, uLong len) { linkedlist_datablock_internal *ldi; const unsigned char *from_copy; if (ll == NULL) return ZIP_INTERNALERROR; if (ll->last_block == NULL) { ll->first_block = ll->last_block = allocate_new_datablock(); if (ll->first_block == NULL) return ZIP_INTERNALERROR; } ldi = ll->last_block; from_copy = (unsigned char *)buf; while (len > 0) { uInt copy_this; uInt i; unsigned char *to_copy; if (ldi->avail_in_this_block == 0) { ldi->next_datablock = allocate_new_datablock();