Add --which to help with debugging path problems

src/bin/sfdoc

@@ -12,6 +12,7 @@ usage() {
         "[options] MODULE"                                              \
         "[options] --ls [MODULE]"                                       \
         "[options] --ls{var|fun} MODULE"                                \
+        "[options] --which"                                             \
         "[options] --lsmod"                                             \
         "[options] --export FMT MODULE"                                 \
         -c                                                              \
@@ -20,6 +21,7 @@ usage() {
             "-L, --lsmod        show list of modules"                   \
             " --lsfun MODULE    show list of functions in MODULE"       \
             " --lsvar MODULE    show list of variables in MODULE"       \
+            " --which MODULE    show path to MODULE file"               \
             "-e, --export FMT MODULE   export MODULE documentation in"  \
             "                   format FMT: 'markdown', 'manpage' and"  \
             "                   'pod' are supported"                    \
@@ -75,6 +77,7 @@ main() {
         -I|--include)   SHELLFU_PATH="$2:$SHELLFU_PATH"; shift 2 || usage ;;
         -l|--ls)        action=lsx;                 shift; break ;;
         -L|--lsmod)     action=lsm;                 shift; break ;;
+        --which)        action=wch;                 shift; break ;;
         -o|--only-from) SHELLFU_PATH="$2"; SHELLFU_INCLUDE=""; shift 2 || usage ;;
         --lsvar)        action=lsv;                 shift; break ;;
         --lsfun)        action=lsf;                 shift; break ;;
@@ -88,11 +91,11 @@ main() {
     debug -v SHELLFU_INCLUDE SHELLFU_PATH SFDOC_SHOW_HIDDEN
     debug -v action format module RealModuleName
     case $action:$module in
-        lsx:*|lsm:*)    true ;;
+        lsx:*|lsm:*|wch:*) true ;;
         *:)             usage ;;
     esac
     case $action in
-        lsm)    : ;;
+        lsm|wch) : ;;
         *)      mpath=$(select_mfile "$module") || die ;;
     esac
     case $action in
@@ -128,6 +131,9 @@ main() {
             sfdoc__export manpage "${RealModuleName:-$module}" "$mpath" \
               | man -l -
             ;;
+        wch)
+            select_mfile "$module"
+            ;;
     esac
 }