[racket] Can't open archived .gz file

How to Gunzip
1) Create dirs: target and subdir: /target/source
2) Place all .gz files in subdir: /target/source
3) From target dir command line, run:
   gunzip -r source  ;note that the generated files at this stage are still not
readable.
4) Then run: zcat -r source > new.txt  ;the file new.txt will be readable.

This two-step process is still not ideal to my way of thinking.  I'd prefer:
- a one-step process.
- for the process to generate a series of text files, each corresponding to a
series of .gz files.
(At least the above process does not require issuing a gunzip command for each
uniquely named .gz source file.)