commands: `spack load --list` alias for `spack find --loaded` (#27184)

See #25249 and https://github.com/spack/spack/pull/27159#issuecomment-958163679.
This adds `spack load --list` as an alias for `spack find --loaded`.  The new command is
not as powerful as `spack find --loaded`, as you can't combine it with all the queries or
formats that `spack find` provides.  However, it is more intuitively located in the command
structure in that it appears in the output of `spack load --help`.

The idea here is that people can use `spack load --list`  for simple stuff but fall back to
`spack find --loaded` if they need more.

- add help to `spack load --list` that references `spack find`
- factor some parts of `spack find` out to be called from `spack load`
- add shell tests
- update docs

Co-authored-by: Peter Josef Scheibel <scheibel1@llnl.gov>
Co-authored-by: Richarda Butler <39577672+RikkiButler20@users.noreply.github.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/share/spack/setup-env.fish b/share/spack/setup-env.fish
index 85a453d1c4..d16ee617df 100755
--- a/share/spack/setup-env.fish
+++ b/share/spack/setup-env.fish
@@ -320,6 +320,11 @@ function check_env_activate_flags -d "check spack env subcommand flags for -h, -
             return 0
         end
 
+        # looks for a single `--list`
+        if match_flag $_a "--list"
+            return 0
+        end
+
     end
 
     return 1