iPhone解压码

Question

确实坚持尝试编写代码来解压缩iPhone上的文件或目录。以下是一些用于尝试解压缩简单文本文件的示例代码。它将文件解压缩，但已损坏。(void)loadView {    NSString *DOCUMENTS_FOLDER = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];    NSString *path = [DOCUMENTS_FOLDER stringByAppendingPathComponent:@"sample.zip"];    NSString *unzipeddest = [DOCUMENTS_FOLDER stringByAppendingPathComponent:@"test.txt"];      gzFile file = gzopen([path UTF8String], "rb");    FILE *dest = fopen([unzipeddest UTF8String], "w");    unsigned char buffer[CHUNK];    int uncompressedLength = gzread(file, buffer, CHUNK);    if(fwrite(buffer, 1, uncompressedLength, dest) != uncompressedLength ||     ferror(dest)) {        NSLog(@"error writing data");    }    else{    }    fclose(dest);    gzclose(file);  }

Answer 1

我想要一个简单的解决方案，但在这里找不到我喜欢的解决方案，因此我修改了一个库以实现自己想要的功能。您可能会发现SSZipArchive有用。（它也可以顺便创建zip文件。）

用法：

NSString *path = @"path_to_your_zip_file";

NSString *destination = @"path_to_the_folder_where_you_want_it_unzipped";

[SSZipArchive unzipFileAtPath:path toDestination:destination];

Answer 2

对于gzip，这段代码对我来说效果很好：

数据库是这样准备的：gzip foo.db

关键是遍历gzread（）。上面的示例仅读取前CHUNK字节。

#import <zlib.h>

#define CHUNK 16384

  NSLog(@"testing unzip of database");

  start = [NSDate date];

  NSString *zippedDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"foo.db.gz"];

  NSString *unzippedDBPath = [documentsDirectory stringByAppendingPathComponent:@"foo2.db"];

  gzFile file = gzopen([zippedDBPath UTF8String], "rb");

  FILE *dest = fopen([unzippedDBPath UTF8String], "w");

  unsigned char buffer[CHUNK];

  int uncompressedLength;

  while (uncompressedLength = gzread(file, buffer, CHUNK) ) {

    // got data out of our file

    if(fwrite(buffer, 1, uncompressedLength, dest) != uncompressedLength || ferror(dest)) {

      NSLog(@"error writing data");

    }

  }

  fclose(dest);

  gzclose(file);

  NSLog(@"Finished unzipping database");

顺便说一句，我可以在77秒内将33MB解压缩到130MB，或者每秒压缩约1.7MB。