zlib - compress 함수

/*
× zlib compress uncompress     ，
×                  
××××××××××××××××××××××××××××××××××××××××××××××××
×   ：z_compress           ××××××××××
××××××××××××××××××××××××××××××××××××××××××××××××
×     ：     +       +    ××
××××××××××××××××××××××××××××××××××××××××××××××××
*/

#include 
#include 
#include 

int main(int argc,char* argv[]) {
    FILE* file;
    uLong flen;
    unsigned char* fbuf = NULL;
    uLong clen;
    unsigned char* cbuf = NULL;

    //        srcfile           dstfile   
    if(argc<3) {
        printf("Usage: z_compress srcfile dstfile
");
        return -1;
    }

    if ( (file = fopen(argv[1],"rb")) ==NULL) {
        printf("Can\'t open %s!
",argv[1]);
        return -1;
    }

    //            
    fseek(file,0L,SEEK_END); //      
    flen = ftell(file); //       
    fseek(file,0L,SEEK_SET);

    if ( (fbuf=(unsigned char*)malloc(sizeof(unsigned char)* flen))==NULL) {
        printf("No enough memory!
");
        fclose(file);
        return -1;
    }
    fread(fbuf, sizeof(unsigned char),flen,file);

    //     
    clen = compressBound(flen);
    if ( (cbuf=(unsigned char*)malloc(sizeof(unsigned char)* clen))==NULL) {
        printf("No enough memory!
");
        fclose(file);
        return -1;
    }
    if (compress(cbuf,&clen,fbuf,flen)!=Z_OK) {
        printf("Compress %s failed!
",argv[1]);
        return -1;
    }
    fclose(file);

    if ((file = fopen(argv[2],"wb")) ==NULL) {
        printf("Can\'t create %s!
",argv[2]);
        return -1;
    }

    //              
    fwrite(&flen, sizeof(uLong),1,file); //        
    fwrite(&clen,sizeof(uLong),1,file); //        
    fwrite(cbuf,sizeof(unsigned char),clen,file);
    fclose(file);

    free(fbuf);
    free(cbuf);

    return 0;
}