better gzip(1) command line option compatibility: Support -l for gzip files

[dirkmueller]

Is your feature request related to a problem? Please describe. I'm experimenting with the "gzip" symlink on zstd binary and notice that there these compatibility options missing:

-n --no-name When compressing, do not save the original file name and time stamp by default. (The original name is always saved if the name had to be truncated.)

-l --list For each compressed file, list the following fields: compressed size: size of the compressed file uncompressed size: size of the uncompressed file ratio: compression ratio (0.0% if unknown) uncompressed_name: name of the uncompressed file

While listing is available as an option, it just aborts with an error message:

zstd --format=gzip -l *gz
Frames  Skips  Compressed  Uncompressed  Ratio  Check  Filename
File "test-0.1.0.tar.gz" not compressed by zstd

Describe the solution you'd like

provide more drop-in compatibility when used via a symlink to "gzip" with the gzip command line options, as documented here (and elsewhere): https://linux.die.net/man/1/gzip

[terrelln]

The only suggestion left from this pr is support for -l with gzip files. I think that is a reasonable request, but it isn't super high priority.

[dirkmueller]

Might take a look at it over the holidays.