home-manager: rewrite argument parsing

This rewrite allows "long options" but unfortunately does not allow
merged options such as `-vn`.

Also improve the home-manager manual page, with this it should include
all sub-commands and arguments.

Finally, include the home-manager manual page in the generated HTML
documentation.

2 files changed, 70 insertions, 43 deletions

diff --git a/home-manager/completion.bash b/home-manager/completion.bash
index cb7c0009693..501b87279fa 100644
--- a/home-manager/completion.bash
+++ b/home-manager/completion.bash
@@ -49,9 +49,13 @@
 # -A
 # -I
 # -f
+# --file
 # -h
+# --help
 # -n
+# --dry-run
 # -v
+# --verbose
 # build
 # edit
 # expire-generations
@@ -61,6 +65,7 @@
 # packages
 # remove-generations
 # switch
+# uninstall
 
 # $ home-manager e<TAB>
 #
@@ -88,15 +93,21 @@
 #   expire-generations
 #   packages
 #   news
+#   uninstall
 
 # « home-manager » Options:
 #
+#   -b EXT
 #   -f FILE
+#   --file FILE
 #   -A ATTRIBUTE
 #   -I PATH
 #   -v
+#   --verbose
 #   -n
+#   --dry-run
 #   -h
+#   --help
 
 # $ home-manager
 #
@@ -109,6 +120,7 @@
 #   -A ATTRIBUTE Optional attribute that selects a configuration
 #                expression in the configuration file.
 #   -I PATH      Add a path to the Nix expression search path.
+#   -b EXT       Move existing files to new path rather than fail.
 #   -v           Verbose output
 #   -n           Do a dry run, only prints what actions would be taken
 #   -h           Print this help
@@ -138,7 +150,8 @@
 #
 #   news         Show news entries in a pager
 #
-
+#   uninstall    Remove Home Manager
+#
 ##################################################
 # Dependencies:
 
@@ -265,14 +278,14 @@ _home-manager_completions ()
     #--------------------------#
 
     local Subcommands
-    Subcommands=( "help" "edit" "build" "switch" "generations" "remove-generations" "expire-generations" "packages" "news" )
+    Subcommands=( "help" "edit" "build" "switch" "generations" "remove-generations" "expire-generations" "packages" "news" "uninstall" )
 
     # ^ « home-manager »'s subcommands.
 
     #--------------------------#
 
     local Options
-    Options=( "-f" "-A" "-I" "-h" "-n" "-v" )
+    Options=( "-f" "--file" "-b" "-A" "-I" "-h" "--help" "-n" "--dry-run" "-v" "--verbose" "--show-trace" )
 
     # ^ « home-manager »'s options.
 
@@ -304,7 +317,7 @@ _home-manager_completions ()
 
     case "$PreviousWord" in
 
-        "-f")
+        "-f"|"--file")
 
             COMPREPLY+=( $( compgen -A file -- "$CurrentWord") )
             ;;
diff --git a/home-manager/home-manager b/home-manager/home-manager
index b6ea92edb9e..bd81fc92357 100644
--- a/home-manager/home-manager
+++ b/home-manager/home-manager
@@ -93,12 +93,14 @@ function doBuildAttr() {
         nix build \
             -f "<home-manager/home-manager/home-manager.nix>" \
             $extraArgs \
+            ${PASSTHROUGH_OPTS[*]} \
             --argstr confPath "$HOME_MANAGER_CONFIG" \
             --argstr confAttr "$HOME_MANAGER_CONFIG_ATTRIBUTE"
     else
         nix-build \
             "<home-manager/home-manager/home-manager.nix>" \
             $extraArgs \
+            ${PASSTHROUGH_OPTS[*]} \
             --argstr confPath "$HOME_MANAGER_CONFIG" \
             --argstr confAttr "$HOME_MANAGER_CONFIG_ATTRIBUTE"
     fi
@@ -451,62 +453,69 @@ function doHelp() {
 
 EXTRA_NIX_PATH=()
 HOME_MANAGER_CONFIG_ATTRIBUTE=""
+PASSTHROUGH_OPTS=()
+COMMAND=""
+COMMAND_ARGS=()
 
-# As a special case, if the user has given --help anywhere on the
-# command line then print help and exit.
-for arg in "$@"; do
-    if [[ $arg == "--help" ]]; then
-        doHelp
-        exit 0
-    fi
-done
-
-while getopts 2f:I:A:b:vnh opt; do
+while [[ $# -gt 0 ]]; do
+    opt="$1"
+    shift
     case $opt in
-        2)
+        build|edit|expire-generations|generations|help|news|packages|remove-generations|switch|uninstall)
+            COMMAND="$opt"
+            ;;
+        -2)
             USE_NIX2_COMMAND=1
             ;;
-        f)
-            HOME_MANAGER_CONFIG="$OPTARG"
+        -A)
+            HOME_MANAGER_CONFIG_ATTRIBUTE="$1"
+            shift
             ;;
-        I)
-            EXTRA_NIX_PATH+=("$OPTARG")
+        -I)
+            EXTRA_NIX_PATH+=("$1")
+            shift
             ;;
-        A)
-            HOME_MANAGER_CONFIG_ATTRIBUTE="$OPTARG"
+        -b)
+            export HOME_MANAGER_BACKUP_EXT="$1"
+            shift
             ;;
-        b)
-            export HOME_MANAGER_BACKUP_EXT="$OPTARG"
+        -f|--file)
+            HOME_MANAGER_CONFIG="$1"
+            shift
             ;;
-        v)
-            export VERBOSE=1
+        -h|--help)
+            doHelp
             ;;
-        n)
+        -n|--dry-run)
             export DRY_RUN=1
             ;;
-        h)
-            doHelp
-            exit 0
+        --show-trace)
+            PASSTHROUGH_OPTS+=("$opt")
+            ;;
+        -v|--verbose)
+            export VERBOSE=1
             ;;
         *)
-            doHelp >&2
-            exit 1
+            case $COMMAND in
+                expire-generations|remove-generations)
+                    COMMAND_ARGS+=("$opt")
+                    ;;
+                *)
+                    errorEcho "$0: unknown option '$opt'"
+                    errorEcho "Run '$0 --help' for usage help"
+                    exit 1
+                    ;;
+            esac
             ;;
     esac
 done
 
-# Get rid of the options.
-shift "$((OPTIND-1))"
-
-if [[ $# -eq 0 ]]; then
+if [[ -z $COMMAND ]]; then
     doHelp >&2
     exit 1
 fi
 
-cmd="$1"
-shift 1
-
-case "$cmd" in
+case $COMMAND in
     edit)
         doEdit
         ;;
@@ -520,10 +529,15 @@ case "$cmd" in
         doListGens
         ;;
     remove-generations)
-        doRmGenerations "$@"
+        doRmGenerations "${COMMAND_ARGS[@]}"
         ;;
     expire-generations)
-        doExpireGenerations "$@"
+        if [[ ${#COMMAND_ARGS[@]} != 1 ]]; then
+            errorEcho "expire-generations expects one argument, got ${#COMMAND_ARGS[@]}."
+            exit 1
+        else
+            doExpireGenerations "${COMMAND_ARGS[@]}"
+        fi
         ;;
     packages)
         doListPackages
@@ -534,11 +548,11 @@ case "$cmd" in
     uninstall)
         doUninstall
         ;;
-    help|--help)
+    help)
         doHelp
         ;;
     *)
-        errorEcho "Unknown command: $cmd"
+        errorEcho "Unknown command: $COMMAND"
         doHelp >&2
         exit 1
         ;;