create-env: Allow passing PREFIX via --prefix=...

Signed-off-by: Marcel Bargull <[email protected]>

images/create-env/create-env

@@ -4,7 +4,7 @@ for arg do
   case "${arg}" in
     --help )
       cat <<'end-of-help'
-Usage: create-env [OPTIONS]... [--] PREFIX [CONDA_CREATE_ARGS]...
+Usage: create-env [OPTIONS]... [--] [PREFIX] [CONDA_CREATE_ARGS]...
 Use conda (or mamba via --conda=mamba) to create a Conda environment at PREFIX
 according to specifications given by CONDA_CREATE_ARGS.
 
@@ -19,6 +19,8 @@ according to specifications given by CONDA_CREATE_ARGS.
                               script. (default: PREFIX/env-activate.sh)
   --env-execute-script=FILE   Destination path of environment execution script.
                               (default: PREFIX/env-execute)
+  --prefix=PREFIX             Destination path of environment.
+                              If omitted, first positional argument is PREFIX.
   --remove-paths=GLOB         Glob of paths to remove from PREFIX after its
                               creation. Can be passed on multiple times. Will
                               be passed on to `find -path PREFIX/GLOB`.
@@ -57,6 +59,9 @@ end-of-help
           "${arg#--remove-paths=}"
       )"
       shift ;;
+    --prefix=* )
+      prefix="${arg#--prefix=}"
+      shift ;;
     --strip-files=* )
       strip_files_globs="$(
         printf '%s\n' \
@@ -78,13 +83,15 @@ end-of-help
   esac
 done
 
-if [ $# -eq 0 ] ; then
-  printf 'missing argument: environment path\n'
-  exit 1
+if [ -z "${prefix+x}" ] ; then
+  if [ $# -eq 0 ] ; then
+    printf 'missing argument: environment path\n' 1>&2
+    exit 1
+  fi
+  prefix="${1}"
+  shift
 fi
-
-prefix="${1%%/}"
-shift
+prefix="${prefix%%/}"
 
 conda_impl="${conda_impl:-conda}"
 create_command="${create_command-create}"