gzip, gunzip, zcat
$ gzip [--keep] [--stdout] [--decompress] <FILES...>
$ gunzip [--keep] [--stdout] <FILES...>
$ zcat <FILES...>
-k
, --keep
: Keep (don't delete) input files-c
, --stdout
: Write to stdout, keep original files unchanged-d
, --decompress
: DecompressFILES
: Files