Revamp reading mechanism; use strategy

Now by default iniread will stop at first file; old behavior can be
restored by -j|--join switch.

include/ini.sh

@@ -70,30 +70,58 @@ __iniread__fltsct() {
 
 
 __iniread__merge() {
+    local path
+    debug -v strategy
+    while read path;
+    do
+        debug -v path
+        case $strategy in
+            first)
+                local winner
+                if test -f "$path";
+                then
+                    debug "winner: $path"
+                    cat "$path"
+                    cat >/dev/null  # throw away rest of paths
+                fi
+                ;;
+            join)
+                debug -v path
+                echo "# file: ${path/$HOME/~}"
+                cat "$path" 2>/dev/null
+                ;;
+        esac
+    done
+}
+
+
+__iniread__load() {
     if test -z "$1";
     then                # guess filename from section head
         local guess="$(cut -d. -f1 <<<"$wntsct")$FFOO_INI_SUFFIX"
         debug -v guess
-        __iniread__merge "$guess"
+        __iniread__load "$guess"
     fi
     local arg trydir trypath
     for arg in "$@";
     do
         case $arg in
             -|*/*)      # stdin, or path (with slash)
-                cat $arg
+                debug -v arg
+                cat "$arg"
             ;;
         *)              # name given, find all its incarnations
             debug -v FFOO_INI_PATH
-            echo "$FFOO_INI_PATH" \
+            echos "$FFOO_INI_PATH" \
               | tr ':' '\n' \
               | while read trydir;
                 do
-                    test -z "$trydir" && continue
+                    test -n "$trydir" || continue
                     trypath="$trydir/$arg"
                     debug -v trypath
-                    cat $trypath 2>/dev/null
-                done
+                    echos "$trypath"
+                done \
+              |  __iniread__merge
             ;;
         esac
     done
@@ -106,8 +134,8 @@ iniread() {
     # A flexible (not just) .ini file reader
     #
     # Usage:
-    #   iniread [-S] [-1] [-s section] [-k key] [file...]
-    #   iniread [-S] [-1] [-p path] [file...]
+    #   iniread [-S] [-1] [-j] [-s section] [-k key] [file...]
+    #   iniread [-S] [-1] [-j] [-p path] [file...]
     #
     #
     # Selection
@@ -155,9 +183,19 @@ iniread() {
     #     yield more than one path, which is equivalent as if
     #     all paths were provided.)
     #
-    # Any files are simply concatenated. (This means that if a
-    # section is queried that is present in both files, it is
-    # effectively concatenated as well.
+    #     Not all files expanded based on `$FFOO_INI_PATH`
+    #     are read by default; reading is governed by "read
+    #     strategy": the default strategy "first" reads only
+    #     the first existing file.  "join" strategy means
+    #     that any files are simply concatenated and prefixed
+    #     with comment containing path to the file, which can
+    #     be observed in strict mode.  (This means that if a
+    #     section is queried that is present in both files,
+    #     it is effectively concatenated as well.
+    #
+    #     The read strategy can be specified using parameter
+    #     `--read-strategy`, while `-j` or `--join` is a
+    #     shorthand for `--read-strategy join`
     #
     # Without *file* given at all, same procedure is used as in
     # case of filename without slash, except that *file* argument
@@ -173,16 +211,23 @@ iniread() {
     local sct_ok=true
     local one_line=false
     local grepex="."  # i.e. throw away empty lines
+    local strategy="first"
     while true; do case $1 in
         --)                                                       break   ;;
         -1|--one-line) one_line=true;                             shift 1 ;;
+        -j|--join)     strategy="join";                           shift 1 ;;
         -k|--key)      wntkey="$2";                               shift 2 ;;
         -p|--path)     wntkey="${2##*.}"; wntsct="${2%.$wntkey}"; shift 2 ;;
         -s|--section)  wntsct="$2"; sct_ok=false;                 shift 2 ;;
         -S|--strict)   strict=true;                               shift 1 ;;
         -l|-L)         warn "--list-* not implemented yet";       shift 1 ;;
+        --read-strategy) strategy="$2";                           shift 2 ;;
         *)                                                        break   ;;
     esac done
+    case "$strategy" in
+        first|join)                                   : ;;
+        *) warn "invalid read strategy: $strategy"; return 2 ;;
+    esac
     fltsct=__iniread__cat
     fltkey=__iniread__cat
     fltcmt=__initead_fltcmt
@@ -194,7 +239,7 @@ iniread() {
     $strict && fltcmt=__iniread__cat
     debug -v wntkey wntsct
     debug "\$@='$@'"
-    __iniread__merge "$@" \
+    __iniread__load "$@" \
         | $fltcmt \
         | $fltsct \
         | $fltkey \