accelerate decently with ls sorting and ignore more stuff

sh/decently

@@ -15,12 +15,31 @@ decently() ( ### @-
     ### has its timestamp updated. symlinks are followed.
     ### `.git` subdirectories are skipped over.
     ### the timestamps of subdirectories are ignored.
-    local arg= dir= latest= prev= ts= fails= succs=0
-    finder() { find "$dir" -type f "$@" '!' -path '*/.git/*' -print -quit; }
     [ -n "$1" ] || { printf '%s: missing directory argument\n' decently >&2; return 1; }
+
+    local arg= dir= latest= prev= ts= fails= succs=0
+
+    finder() {
+        find "$dir" -type f "$@" \
+        '!' \
+        '(' -path '*/.git/*' \
+        -or -path '*/__pycache__/*' \
+        -or -path '*/[Dd]esktop.ini' \
+        -or -path '*/Thumbs.db' \
+        -or -path '*/.DS_Store' \
+        ')' \
+        -exec ls -t1 '{}' + \
+          2>/dev/null \
+          | while read -r f; do
+            printf '%s\n' "$f"
+            break
+        done
+    }
+
     for arg; do
         dir="$(readlink -f -- "$arg")" || continue
         [ -d "$dir" ] || { printf '%s: not a directory: %s\n' decently "$dir" >&2; continue; }
+
         prev=
         latest="$(finder)" || continue
         while [ -n "$latest" ]; do
@@ -28,12 +47,14 @@ decently() ( ### @-
             latest="$(finder -newer "$latest")" || break
         done
         [ -e "$prev" ] || { printf '%s: no valid files found: %s\n' decently "$dir" >&2; continue; }
+
         ts="$(date -u '+%s' -r "$prev")"
         dir="${dir%/}/" # ensure dir has a trailing slash
         printf '%s\t%s\n' "$ts" "${arg%/}/${prev#$dir}"
         touch -c -r "$prev" "$dir" || continue
         : $(( succs+=1 ))
     done
+
     fails=$(( $# - succs ))
     [ $fails -le 255 ] || fails=255
     return $fails