用来压缩和解压的，以下是部分函数： int compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen); int compress2 (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level); int uncompress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen); typedef voidp gzFile; gzFile gzopen (const char *path, const char *mode); gzFile gzdopen (int fd, const char *mode); int gzsetparams (gzFile file, int level, int strategy); int gzread (gzFile file, voidp buf, unsigned len); int gzwrite (gzFile file, const voidp buf, unsigned len); int VA gzprintf (gzFile file, const char *format, ...); int gzputs (gzFile file, const char *s); char * gzgets (gzFile file, char *buf, int len); int gzputc (gzFile file, int c); int gzgetc (gzFile file); int gzflush (gzFile file, int flush); z_off_t gzseek (gzFile file, z_off_t offset, int whence); z_off_t gztell (gzFile file); int gzrewind (gzFile file); int gzeof (gzFile file); int gzclose (gzFile file); const char * gzerror (gzFile file, int *errnum);