c语言txt文件压缩的方法是什么

在C语言中，可以使用一些开源的库来实现txt文件的压缩，比如zlib库。以下是一个简单的示例代码，用来实现txt文件的压缩：

#include <
    stdio.h>
    
#include <
    stdlib.h>
    
#include <
    string.h>
    
#include <
    zlib.h>


#define CHUNK_SIZE 16384

int compress_file(const char *source_file, const char *dest_file) {
    
    FILE *source = fopen(source_file, "rb");

    if (!source) {
    
        fprintf(stderr, "Error opening source file\n");
    
        return -1;

    }
    

    FILE *dest = fopen(dest_file, "wb");

    if (!dest) {
    
        fprintf(stderr, "Error opening destination file\n");
    
        fclose(source);
    
        return -1;

    }
    

    z_stream stream;
    
    stream.zalloc = Z_NULL;
    
    stream.zfree = Z_NULL;
    
    stream.opaque = Z_NULL;
    
    stream.avail_in = 0;
    
    stream.next_in = Z_NULL;
    

    if (deflateInit(&
stream, Z_DEFAULT_COMPRESSION) != Z_OK) {
    
        fprintf(stderr, "Error initializing zlib\n");
    
        fclose(source);
    
        fclose(dest);
    
        return -1;

    }
    

    unsigned char in[CHUNK_SIZE];
    
    unsigned char out[CHUNK_SIZE];
    

    int ret;

    do {
    
        stream.avail_in = fread(in, 1, CHUNK_SIZE, source);

        if (ferror(source)) {
    
            fprintf(stderr, "Error reading from source file\n");
    
            deflateEnd(&
    stream);
    
            fclose(source);
    
            fclose(dest);
    
            return -1;

        }
    
        stream.next_in = in;


        do {
    
            stream.avail_out = CHUNK_SIZE;
    
            stream.next_out = out;
    
            ret = deflate(&
    stream, stream.avail_in ? Z_NO_FLUSH : Z_FINISH);

            if (ret == Z_STREAM_ERROR) {
    
                fprintf(stderr, "Error compressing data\n");
    
                deflateEnd(&
    stream);
    
                fclose(source);
    
                fclose(dest);
    
                return -1;

            }
    

            fwrite(out, 1, CHUNK_SIZE - stream.avail_out, dest);

            if (ferror(dest)) {
    
                fprintf(stderr, "Error writing to destination file\n");
    
                deflateEnd(&
    stream);
    
                fclose(source);
    
                fclose(dest);
    
                return -1;

            }

        }
     while (stream.avail_out == 0);

    }
     while (ret != Z_STREAM_END);
    

    deflateEnd(&
    stream);
    
    fclose(source);
    
    fclose(dest);
    

    return 0;

}


int main() {
    
    const char *source_file = "source.txt";
    
    const char *dest_file = "compressed.txt";


    if (compress_file(source_file, dest_file) != 0) {
    
        fprintf(stderr, "Error compressing file\n");
    
        return -1;

    }
    

    printf("File compressed successfully\n");
    

    return 0;

}
    

在上面的代码中，我们使用了zlib库中的deflate函数来实现文件的压缩。首先打开源文件和目标文件，然后使用deflateInit函数初始化压缩流。接下来，我们使用一个循环来读取源文件的数据并进行压缩，最后写入目标文件。最后调用deflateEnd函数释放资源并关闭文件。

请注意，以上代码仅供参考，实际使用时需要根据实际情况进行适当的修改和调整。

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