checked dependencies, made some optional, document optional dependencies

profile.d/filefct.sh

@@ -471,6 +471,12 @@ file_stats()
     fi
 
     # Minimum/maximum size filters (evaluated in bytes)
+    if [[ -n "$min_size" || -n "$max_size" ]]; then
+        if ! command -v numfmt >/dev/null 2>&1; then
+            disp E "file_stats: --min/--max require 'numfmt' (GNU coreutils). Please install it."
+            return 1
+        fi
+    fi
     if [[ -n "$min_size" ]]; then
         find_cmd+=(-size +"$(numfmt --from=iec "$min_size")"c)
     fi

profile.d/fun.sh

@@ -94,6 +94,11 @@ busy()
     delay_s=$(awk "BEGIN{
         printf \"%.3f\", $delay_ms / 1000 }")
 
+    command -v hexdump >/dev/null 2>&1 || {
+        disp E "busy: 'hexdump' is required but not installed (util-linux or bsdmainutils)."
+        return 1
+    }
+
     # Monitor /dev/urandom
     (
         hexdump -C < /dev/urandom | grep -iF --line-buffered "$pattern" | \

profile.d/processes.sh

@@ -199,7 +199,7 @@ export -f ppn
 
 # ------------------------------------------------------------------------------
 # Get PID list of the given process name
-# Usage: ppid <process_name [process_name2 ...]>
+# Usage: gpid <process_name [process_name2 ...]>
 gpid()
 {
     local PARSED
@@ -361,16 +361,33 @@ ku()
             disp E "User '$u' does not exist."
             return 1
         else
-            local cmd=(killall)
+            local cmd
 
-            if [[ ${#signal_opt[@]} -gt 0 ]]; then
-                cmd+=("${signal_opt[@]}")
-            elif [[ -n "${KU_DEFAULT_SIGNAL:-}" ]]; then
-                cmd+=("-${KU_DEFAULT_SIGNAL}")
+            # killall (psmisc) preferred; fall back to pkill (procps-ng).
+            if command -v killall >/dev/null 2>&1; then
+                cmd=(killall)
+                if [[ ${#signal_opt[@]} -gt 0 ]]; then
+                    cmd+=("${signal_opt[@]}")
+                elif [[ -n "${KU_DEFAULT_SIGNAL:-}" ]]; then
+                    cmd+=("-${KU_DEFAULT_SIGNAL}")
+                fi
+                cmd+=(-u "$u")
+            elif command -v pkill >/dev/null 2>&1; then
+                cmd=(pkill)
+                # Translate killall's -s SIGNAME form to pkill's -SIGNAME form.
+                if [[ ${#signal_opt[@]} -eq 2 && "${signal_opt[0]}" == "-s" ]]; then
+                    cmd+=("-${signal_opt[1]}")
+                elif [[ ${#signal_opt[@]} -gt 0 ]]; then
+                    cmd+=("${signal_opt[@]}")
+                elif [[ -n "${KU_DEFAULT_SIGNAL:-}" ]]; then
+                    cmd+=("-${KU_DEFAULT_SIGNAL}")
+                fi
+                cmd+=(-u "$u")
+            else
+                disp E "ku: neither 'killall' (psmisc) nor 'pkill' (procps) is available."
+                return 1
             fi
 
-            cmd+=(-u "$u")
-
             if (( dry_run )); then
                 printf "DRY-RUN: "
                 printf "%q " "${cmd[@]}"