This is a fish function:

function cargo-registry --argument-names query
  set -l r \
    ~/.cargo/registry/src/index.crates.io-*/
  set -l c (
    ls -d $r*/ 2>/dev/null \
    | xargs -n 1 basename
  )

  if test -z "$query"
    printf '%s\n' $c \
    | sort
  else
    printf '%s\n' $c \
    | grep -i "$query" \
    | sort
  end
end

And what it does is:

❯ cargo-registry|head
ab_glyph_rasterizer-0.1.9
ab_glyph-0.2.31
accesskit_consumer-0.28.0
accesskit_macos-0.20.0
accesskit_winit-0.27.0
accesskit-0.19.0
adler2-2.0.1
adler2-2.0.1
ahash-0.8.12
ahash-0.8.12
aho-corasick-1.1.3
allocator-api2-0.2.21
allocator-api2-0.2.21
anstream-0.6.19
anstream-0.6.19
anstyle-1.0.11
anstyle-1.0.11
anstyle-parse-0.2.7
anstyle-parse-0.2.7
anstyle-query-1.1.3
# ...

And also:

❯ cargo-registry egui
egui_glow-0.32.0
egui-0.32.0
egui-wgpu-0.32.0
egui-winit-0.32.0

#fish #shell

Without “| xargs -n 1 basename” would change the output stream to absolute path. With that in mind:

function cargo-registry
  argparse 'a/all' 'q/query=' -- $argv
  or return
  set -l q ""
  if set -q _flag_query
    set q "$_flag_query"
  else
    set q "$argv[1]"
  end
  set -l r \
    ~/.cargo/registry/src/index.crates.io-*/
  set -l dirs
  if set -q _flag_all
    set dirs (ls -d $r*/ 2>/dev/null)
  else
    set dirs (
      ls -d $r*/ 2>/dev/null \
      | xargs -n 1 basename
    )
  end
  if test -z "$q"
    printf '%s\n' $dirs \
    | sort
  else
    printf '%s\n' $dirs \
    | grep -i "$q" \
    | sort
  end
end

Results:

~ main
❯ cargo-registry | head -5
ab_glyph_rasterizer-0.1.9
ab_glyph-0.2.31
accesskit_consumer-0.28.0
accesskit_macos-0.20.0
accesskit_winit-0.27.0

~ main
❯ cargo-registry -a | head -5
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ab_glyph_rasterizer-0.1.9/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ab_glyph-0.2.31/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/accesskit_consumer-0.28.0/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/accesskit_macos-0.20.0/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/accesskit_winit-0.27.0/

~ main
❯ cargo-registry egui
egui_glow-0.32.0
egui-0.32.0
egui-wgpu-0.32.0
egui-winit-0.32.0

~ main
❯ cargo-registry egui -a
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/egui_glow-0.32.0/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/egui-0.32.0/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/egui-wgpu-0.32.0/
/Users/jarkko/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/egui-winit-0.32.0/