linux开发---28.【C】用libz库压缩与解压缩的测试

1.测试压缩与解压缩的demo

2. 代码如下
test.cpp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <zlib.h>
#define dbmsg(fmt, args ...) printf("%s:%s[%d]: "fmt"\n", __FILE__,__FUNCTION__, __LINE__,##args)

/* Compress gzip data */
int gzcompress(Bytef *data, uLong ndata,
    Bytef *zdata, uLong *nzdata)
{
    z_stream c_stream;
    int err = 0;

    if(data && ndata > 0)
    {
        c_stream.zalloc = (alloc_func)0;
        c_stream.zfree = (free_func)0;
        c_stream.opaque = (voidpf)0;
        if(deflateInit2(&c_stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
                    -MAX_WBITS, 8, Z_DEFAULT_STRATEGY) != Z_OK) return -1;
        c_stream.next_in = data;
        c_stream.avail_in = ndata;
        c_stream.next_out = zdata;
        c_stream.avail_out = *nzdata;
        while (c_stream.avail_in != 0 && c_stream.total_out < *nzdata)
        {
            if(deflate(&c_stream, Z_NO_FLUSH) != Z_OK) return -1;
        }
        if(c_stream.avail_in != 0) return c_stream.avail_in;
        for (;;) {
            if((err = deflate(&c_stream, Z_FINISH)) == Z_STREAM_END) break;
            if(err != Z_OK) return -1;
        }
        if(deflateEnd(&c_stream) != Z_OK) return -1;
        *nzdata = c_stream.total_out;
        return 0;
    }
    return -1;
}

/* Uncompress gzip data */
int gzdecompress(Byte *zdata, uLong nzdata,
        Byte *data, uLong *ndata)
{
    int err = 0;
    z_stream d_stream = {0}; /* decompression stream */
    static char dummy_head[2] =
    {
        0x8 + 0x7 * 0x10,
        (((0x8 + 0x7 * 0x10) * 0x100 + 30) / 31 * 31) & 0xFF,
    };
    d_stream.zalloc = (alloc_func)0;
    d_stream.zfree = (free_func)0;
    d_stream.opaque = (voidpf)0;
    d_stream.next_in = zdata;
    d_stream.avail_in = 0;
    d_stream.next_out = data;
    if(inflateInit2(&d_stream, -MAX_WBITS) != Z_OK) return -1;
    //if(inflateInit2(&d_stream, 47) != Z_OK) return -1;
    while (d_stream.total_out < *ndata && d_stream.total_in < nzdata) {
        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
        if((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_STREAM_END) break;
        if(err != Z_OK )
        {
            if(err == Z_DATA_ERROR)
            {
                d_stream.next_in = (Bytef*) dummy_head;
                d_stream.avail_in = sizeof(dummy_head);
                if((err = inflate(&d_stream, Z_NO_FLUSH)) != Z_OK)
                {
                    return -1;
                }
            }
            else return -1;
        }
    }
    if(inflateEnd(&d_stream) != Z_OK) return -1;
    *ndata = d_stream.total_out;
    return 0;
}

int file_read(char** pData)
{
    char *pchBuf = NULL;
    int nLen = 0;
    FILE *pF = fopen("siminfo_ok.xml", "r"); //打开文件
    if(NULL== pF)
    {
        dbmsg("file open error=%s",strerror(errno));
        return -2;
    }

    fseek(pF, 0, SEEK_END); //文件指针移到文件尾
    nLen = ftell(pF); //得到当前指针位置, 即是文件的长度
    rewind(pF); //文件指针恢复到文件头位置

    //动态申请空间, 为保存字符串结尾标志\0, 多申请一个字符的空间
    pchBuf = (char*) malloc(sizeof(char)*nLen+1);
    if(!pchBuf)
    {
        perror("内存不够!\n");
        exit(0);
    }

    //读取文件内容//读取的长度和源文件长度有可能有出入，这里自动调整 nLen
    nLen = fread(pchBuf, sizeof(char), nLen, pF);

    pchBuf[nLen] = '\0'; //添加字符串结尾标志

    //printf("%s\n", pchBuf); //把读取的内容输出到屏幕看看

    fclose(pF); //关闭文件
    *pData = pchBuf;
// free(pchBuf); //释放空间

    return nLen;
}

#define BUF_SIZE 65535
int main()
{
    //char *data = "kjdalkfjdflkjdlkfjdklfjdlkfjlkdjflkdjflddajfkdjfkdfaskf;ldsfk;ldakf;ldskfl;dskf;ld";
    //uLong ndata = strlen(data);
    char * data;
    uLong ndata = file_read(&data);
    Bytef zdata[BUF_SIZE];
    uLong nzdata = BUF_SIZE;
    Bytef  odata[BUF_SIZE];
    uLong nodata = BUF_SIZE;

    memset(zdata, 0, BUF_SIZE);

    if(gzcompress((Bytef *)data, ndata, zdata, &nzdata) == 0)
    {
        fprintf(stdout, "nzdata:%d %s\n", nzdata, zdata);
#if 1
    printf("orgin_len=%d, compressed_len=%d\n", ndata, nzdata);
    for(int i=0; i<nzdata; i++)
    {
        //printf("%d=0x%x ", i,(unsigned char)base_info[i]);
        printf("0x%x ", zdata[i]);
        if((i+1)%10==0)
            printf("\n");
    }
    printf("\n");
#endif
        memset(odata, 0, BUF_SIZE);
        //if(gzdecompress(zdata, ndata, odata, &nodata) == 0) //ok
        if(gzdecompress(zdata, ndata, odata, &nodata) == 0) //ok
        {
            //fprintf(stdout, "%d %s\n", nodata, odata);
        }
    }
}

Makefile

####################################################
# Generic makefile - 万能Makefile
# for compiling and linking C++ projects on Linux
# Author: George Foot  Modified:Jackie Lee
####################################################
### Customising
#
# Adjust the following if necessary; EXECUTABLE is the target
# executable's filename, and LIBS is a list of libraries to link in
# (e.g. alleg, stdcx, iostr, etc). You can override these on make's
# command line of course, if you prefer to do it that way.
#
#
EXECUTABLE := test
INCLUDES:=../../include ./
SRCDIR:=
#
# # Now alter any implicit rules' variables if you like, e.g.:

CC:=g++
CFLAGS := -g -Wall -O3
CPPFLAGS := $(CFLAGS)
CPPFLAGS += $(addprefix -I,$(INCLUDES))
CPPFLAGS += -MMD
LDFLAGS = -Wl,-Bstatic -L../lib/ -lz -Wl,-Bdynamic -pthread -Wl,-Bdynamic
#
# # The next bit checks to see whether rm is in your djgpp bin
# # directory; if not it uses del instead, but this can cause (harmless)
# # `File not found' error messages. If you are not using DOS at all,
# # set the variable to something which will unquestioningly remove
# # files.
#

RM-F := rm -f


# # You shouldn't need to change anything below this point.
#
SRCS := $(wildcard *.cpp) $(wildcard $(addsuffix /*.cpp, $(SRCDIR)))
OBJS := $(patsubst %.cpp,%.o,$(SRCS))
DEPS := $(patsubst %.o,%.d,$(OBJS))
MISSING_DEPS := $(filter-out $(wildcard $(DEPS)),$(DEPS))
MISSING_DEPS_SOURCES := $(wildcard $(patsubst %.d,%.cpp,$(MISSING_DEPS)))


.PHONY : all deps objs clean veryclean rebuild info

all: $(EXECUTABLE)

deps : $(DEPS)

objs : $(OBJS)

clean :
    @$(RM-F) *.o
    @$(RM-F) *.d
    @$(RM-F) $(EXECUTABLE)

rebuild: veryclean all
ifneq ($(MISSING_DEPS),)
$(MISSING_DEPS) :
    @$(RM-F) $(patsubst %.d,%.o,$@)
endif
-include $(DEPS)
$(EXECUTABLE) : $(OBJS)
    $(CC) -o $(EXECUTABLE) $(OBJS) $(LDFLAGS)

info:
    @echo $(SRCS)
    @echo $(OBJS)
    @echo $(DEPS)
    @echo $(MISSING_DEPS)
    @echo $(MISSING_DEPS_SOURCES)

3. 代码下载
gzip.rar(下载后改名为gzip.tar.gz)