Merge pull request #1 from pfheatwole/work

Eliminate dependency on `column` and add raw output

README.rst

@@ -14,27 +14,17 @@ virtual environments, regardless of how they were created (``python -m venv
 Prerequisites
 -------------
 
-Requires ``find`` from GNU ``findutils`` to collect a list of candidates.
+* GNU coreutils (for ``readlink`` and ``realpath``)
 
-Uses ``column`` from the ``util-linux`` package (if available) for
-pretty-printing the output. If ``column`` is not available, the output is the
-simple form ``<version>:<venv path>``.
+* GNU findutils (for ``find``)
 
 
 Installation
 ------------
 
-Verify that ``$PYENV_ROOT`` has been configured:
-
-.. code-block:: bash
-
-   $ echo $PYENV_ROOT
-
-Install the plugin:
-
 .. code-block:: bash
 
-   $ git clone https://github.com/pyenv/pyenv-users.git "$PYENV_ROOT"/plugins/pyenv-users
+   $ git clone https://github.com/pyenv/pyenv-users.git "$(pyenv root)/plugins/pyenv-users"
 
 
 Usage
@@ -52,20 +42,34 @@ search your home directory:
    3.8.6          /home/peter/.cache/pypoetry/virtualenvs/my_project-KM_3YcvM-py3.8
    pypy3.6-7.3.1  /home/peter/work/venvs/example1
 
+For scripting, use the ``--raw`` option to output a list of ``:`` separated
+items:
 
-Disclaimer
-----------
+.. code-block:: bash
 
-I'm not a script writer so it's probably a bit crude. It's not blazingly fast,
-since it uses a brute force scan, but on my system it only takes 3 seconds,
-and I like the simplicity.
+   $ pyenv users --raw ~
+   3.7.9:/home/peter/.cache/pypoetry/virtualenvs/my_project-KM_3YcvM-py3.7
+   3.7.9:/home/peter/work/venvs/long name with spaces
+   3.8.6:/home/peter/.cache/pypoetry/virtualenvs/my_project-KM_3YcvM-py3.8
+   pypy3.6-7.3.1:/home/peter/work/venvs/example1
 
-I've been using it on Fedora 33 with no issues, but it could use more testing.
-In particular, users on MacOS and Windows will probably prefer the addition of
-a pretty-printing solution that doesn't rely on ``column``.
+For example, to get a list of all versions linked to a virtual environment:
+
+.. code-block:: bash
+
+   $ pyenv users --raw ~ | cut -d: -f1 | uniq
+   3.7.9
+   3.8.6
+   pypy3.6-7.3.1
+
+
+Disclaimer
+----------
 
-Also, I seem to recall that not all versions of ``column`` support the ``-s``
-parameter for setting the separator. I haven't had time to research that.
+The plugin doesn't maintain a list of environments; it generates the list each
+run by performing a brute force scan of the directory for symlinks named
+`python`. This does mean it's not blazingly fast, but its simplicity provides
+state-free reliability, and in practice ``find`` only takes a few seconds.
 
-Tested with ``bash v5.0.17(1)``, ``find v4.7.0``, and ``column v2.36.1`` on
-Fedora 33.
+Also, it could really use more testing; so far I've been using it on Fedora 33
+with no issues. Tested with ``bash v5.0.17(1)`` and ``find v4.7.0``.

bin/pyenv-users

@@ -2,41 +2,86 @@
 #
 # Summary: Find virtual environments that use pyenv-managed versions.
 #
-# Usage: pyenv users [directory]
+# Usage: pyenv users [-r|--raw] [directory]
+#
+#   -r/--raw   Raw output strings as "<version>:<venv-path>"
 #
 # Scans [directory] for virtual environments whose `python` commands
 # are symlinks back into a pyenv version. Default: current directory.
 
-if [ -n "$1" ]; then
-  DIR="$1"
-else
+set -e
+
+parse_options() {
+  # Parse the command line options. Taken from `pyenv-virtualenv`
+  OPTIONS=()
+  ARGUMENTS=()
+  local arg option index
+
+  for arg in "$@"; do
+    if [ "${arg:0:1}" = "-" ]; then
+      if [ "${arg:1:1}" = "-" ]; then
+        OPTIONS[${#OPTIONS[*]}]="${arg:2}"
+      else
+        index=1
+        while option="${arg:$index:1}"; do
+          [ -n "$option" ] || break
+          OPTIONS[${#OPTIONS[*]}]="$option"
+          index=$((index+1))
+        done
+      fi
+    else
+      ARGUMENTS[${#ARGUMENTS[*]}]="$arg"
+    fi
+  done
+}
+
+unset RAW
+parse_options "$@"
+for option in "${OPTIONS[@]}"; do
+  case "$option" in
+  "r" | "raw" )
+    RAW=true
+    ;;
+  "h" | "help" )
+    pyenv help users
+    exit 0
+    ;;
+  esac
+done
+
+if [[ "${#ARGUMENTS[@]}" == 0 ]]; then
   DIR="$PYENV_DIR"
+elif [[ "${#ARGUMENTS[@]}" == 1 ]]; then
+  DIR="${ARGUMENTS[0]}"
+else
+  echo -e "\nToo many directory arguments.\n"
+  pyenv help users
+  exit 1
 fi
 
+# ----------------------------------------------------------------------------
+# Finished parsing the arguments. Begin the actual functionality.
+
+# The `links` are the symlink pathnames, `versions` are pyenv version strings,
+# and `venvs` are venv pathnames. Using parallel arrays since arrays-of-arrays
+# are a pain in bash. Keeping versions and venvs separate avoids needing awk.
+declare -a links versions venvs
+
+if [ -z "$PYENV_ROOT" ]; then
+  PYENV_ROOT=$(pyenv root)
+fi
+
+# Collect all symlinks named `python` that point into $PYENV_ROOT
 cmd="readlink -f '{}' | grep -q ${PYENV_ROOT}"
-unset links i
+unset i
 while IFS= read -r -d $'\0' file; do
   links[i++]="$file"
 done < <(find -H "$DIR" -name "python" -type l -exec sh -c "$cmd" \; -print0)
 
-# Exit if no relevant venvs were found
-if [[ $i -eq 0 ]]; then
-  exit 0
-fi
-
-# Use columnar output if convenient.
-if [ -n "$(command -v column)" ]; then
-  output="column -t -s ':'"
-else
-  output="cat"
-fi
-
-# Regex to extract the pyenv version from the target string. The
-# second group consumes the actual binary (`python`, `pypy3`, etc)
+# Turn each link into a (version, venv) string pair
 regex="${PYENV_ROOT}/versions/(.+)/bin/(.+)"
-
+unset i
 for link in "${links[@]}"; do
-  # `$link` is the `python` symlink, and `$target` is its target.
   linkpath=$(realpath -s "$link")
   target=$(readlink -f "$link")
   [[ "$target" =~ $regex ]]
@@ -45,6 +90,21 @@ for link in "${links[@]}"; do
   if grep -v -q "$PYENV_ROOT" <<< "$linkpath" || \
      grep -q "$PYENV_ROOT/versions/$version/envs" <<< "$linkpath"
   then
-    echo "$version":"${link%/bin/python}"
+    versions[i]="$version"
+    venvs[i++]="${link%/bin/python}"
+  fi
+done
+
+# Print each (version, venv) pair
+declare -i K=${#versions[@]} width=0 maxwidth=0
+for (( k=0; k < K; k++ )); do
+  width=${#versions[k]}
+  if (( width > maxwidth )); then maxwidth=$width; fi
+done
+for (( k=0; k < K; k++ )); do
+  if [ -z "$RAW" ]; then
+    printf "%-*s  %s\n" "$maxwidth" "${versions[$k]}" "${venvs[k]}"
+  else
+    echo "${versions[$k]}":"${venvs[$k]}"
   fi
-done | sort | $output
+done | sort