added rainbow

README.md

@@ -116,6 +116,7 @@ A bar-style prompt showing current time, execution time of the last command
 | `profile_upgrade` | updates | Upgrade profile to the latest version (git pull or archive) |
 | `pwdscore` | pwd | Calculate the strength score of a given password |
 | `rain` | rain | Console screensaver with falling-rain effect (multiple color themes) |
+| `rainbow` | rain | Full-screen rainbow screensaver using only background colors, with horizontal color shifting |
 | `rmhost` | ssh | Remove host (name and IP) from SSH known_hosts; supports `--all-users` as root |
 | `rmspc` | filefct | Replace spaces in filenames with underscores (or a custom character) |
 | `setc` | lang | Set locale to standard C (POSIX) |
@@ -189,6 +190,7 @@ change the default without having to pass flags every time.
 | `RAIN_DEFAULT_SPEED` | `0.1` | Falling speed for `rain` |
 | `RAIN_DEFAULT_COLOR` | `Green` | Colour for `rain` |
 | `RAIN_DEFAULT_DENSITY` | dynamic | Maximum number of simultaneous falling elements for `rain` |
+| `RAINBOW_DEFAULT_SPEED` | `0.04` | Horizontal color shift speed for `rainbow` |
 | `MATRIX_DEFAULT_SPEED` | `0.05` | Falling speed for `matrix` |
 | `MATRIX_DEFAULT_COLOR` | `Green` | Colour for `matrix` |
 | `MATRIX_DEFAULT_DENSITY` | dynamic | Maximum number of simultaneous falling elements for `matrix` |

doc/profile.conf.example

@@ -233,6 +233,10 @@ TERM=xterm-256color
 # Leave unset to keep the terminal-size-based dynamic default.
 #RAIN_DEFAULT_DENSITY=80
 
+# rainbow: Horizontal color shift speed — integer/100 gives seconds (4 → 0.04 s).
+# Values < 1 are used as raw seconds.
+#RAINBOW_DEFAULT_SPEED=4
+
 # matrix: Falling speed.
 #MATRIX_DEFAULT_SPEED=3.5
 

profile.d/help.sh

@@ -89,6 +89,7 @@ help()
     printf "profile_upgrade\tUpgrade profile to the latest version (git pull or archive)\n"
     printf "pwdscore\tCalculate the strength score of a given password\n"
     printf "rain\t\tConsole screensaver with falling-rain effect (multiple color themes)\n"
+    printf "rainbow\t\tFull-screen rainbow screensaver using background colors only\n"
     printf "rmhost\t\tRemove host (name and IP) from SSH known_hosts; supports --all-users as root\n"
     printf "rmspc\t\tReplace spaces in filenames with underscores (or a custom character)\n"
     printf "setlocale\tSet console locale to any installed locale\n"

profile.d/rain.sh

@@ -121,6 +121,76 @@ _rain_normalize_density()
     printf "%s" "$raw_density"
 }
 
+_rainbow_supports_truecolor()
+{
+    case "${COLORTERM:-}" in
+        *truecolor*|*24bit*)
+            return 0
+            ;;
+    esac
+
+    case "${TERM:-}" in
+        *direct*|*truecolor*)
+            return 0
+            ;;
+    esac
+
+    return 1
+}
+
+_rainbow_build_palette()
+{
+    local palette_width="$1"
+    local use_truecolor="$2"
+    local x=0 wheel_pos=0 band=0 blend=0
+    local red=0 green=0 blue=0
+
+    RAINBOW_BG_PALETTE=()
+
+    if (( palette_width < 1 )); then
+        RAINBOW_BG_PALETTE+=("\e[41m")
+        return 0
+    fi
+
+    if (( use_truecolor )); then
+        for ((x = 0; x < palette_width; x++)); do
+            wheel_pos=$((x * 1536 / palette_width))
+            band=$((wheel_pos / 256))
+            blend=$((wheel_pos % 256))
+
+            case "$band" in
+                0)
+                    red=255; green=$blend; blue=0
+                    ;;
+                1)
+                    red=$((255 - blend)); green=255; blue=0
+                    ;;
+                2)
+                    red=0; green=255; blue=$blend
+                    ;;
+                3)
+                    red=0; green=$((255 - blend)); blue=255
+                    ;;
+                4)
+                    red=$blend; green=0; blue=255
+                    ;;
+                *)
+                    red=255; green=0; blue=$((255 - blend))
+                    ;;
+            esac
+
+            RAINBOW_BG_PALETTE+=("\e[48;2;${red};${green};${blue}m")
+        done
+    else
+        local ansi_palette=(41 101 43 103 42 102 46 106 44 104 45 105)
+        local ansi_count=${#ansi_palette[@]}
+
+        for ((x = 0; x < palette_width; x++)); do
+            RAINBOW_BG_PALETTE+=("\e[${ansi_palette[x * ansi_count / palette_width]}m")
+        done
+    fi
+}
+
 _rain_engine()
 {
     local step_duration="$1"
@@ -152,7 +222,6 @@ _rain_engine()
     local term_area=0
     local frame_sleep="$step_duration"
 
-    local sigwinch
     sigwinch()
     {
         term_width=$(tput cols)
@@ -194,13 +263,11 @@ _rain_engine()
         fi
     }
 
-    local do_exit
     do_exit()
     {
         exit_st=1
     }
 
-    local do_render
     do_render()
     {
         local idx=0 y=0 drop_color="" current_char="" render_color=""
@@ -497,6 +564,131 @@ matrix()
     _rain_engine "$step_duration" "$base_color" "matrix" "$charset" "$density_override"
 }
 export -f matrix
+
+# ------------------------------------------------------------------------------
+# Full-screen rainbow screensaver
+# Usage: rainbow [OPTIONS]
+rainbow()
+{
+    local PARSED
+
+    PARSED=$(getopt -o hs: --long help,speed: -n 'rainbow' -- "$@")
+    # shellcheck disable=SC2181 # getopt return code is checked immediately after
+    if [[ $? -ne 0 ]]; then
+        disp E "Invalid options, use \"rainbow --help\" to display usage."
+        return 1
+    fi
+
+    local _raw_speed="${RAINBOW_DEFAULT_SPEED:-4}"
+    local frame_sleep
+    frame_sleep=$(_rain_normalize_speed "$_raw_speed") || frame_sleep=0.040
+
+    eval set -- "$PARSED"
+    while true; do
+        case "$1" in
+            -h|--help)
+                printf "Usage: rainbow [OPTIONS]\n"
+                printf "Options:\n"
+                printf "\t-s, --speed NUM\tSet horizontal color shift speed (default: 4 => 0.040s).\n"
+                printf "\t\t\t\tValues >=1 use a /100 scale (4 => 0.04s).\n"
+                printf "\t\t\t\tValues <1 are interpreted as raw seconds.\n"
+                printf "\t-h, --help\t\tDisplay this help message and exit.\n\n"
+                printf "The rainbow fills the whole terminal with background colors only.\n"
+                printf "It uses truecolor when supported, otherwise ANSI bright backgrounds.\n"
+                printf "Press q to quit.\n"
+                return 0
+                ;;
+            -s|--speed)
+                frame_sleep=$(_rain_normalize_speed "$2") || {
+                    disp E "--speed requires a numeric value."
+                    return 1
+                }
+                shift 2
+                ;;
+            --)
+                shift
+                break
+                ;;
+            *)
+                disp E "Invalid options, use \"rainbow --help\" to display usage."
+                return 1
+                ;;
+        esac
+    done
+
+    command -v tput >/dev/null 2>&1 || {
+        disp E "The program 'tput' is required but not installed."
+        return 1
+    }
+
+    local exit_st=0
+    local term_height=0 term_width=0
+    local use_truecolor=0
+    local offset=0 row=0 col=0 palette_width=0 idx=0
+    local row_line="" ch=""
+
+    sigwinch()
+    {
+        term_width=$(tput cols)
+        term_height=$(tput lines)
+        ((term_width < 1)) && term_width=1
+        ((term_height < 1)) && term_height=1
+
+        if _rainbow_supports_truecolor; then
+            use_truecolor=1
+        else
+            use_truecolor=0
+        fi
+
+        palette_width=$term_width
+        _rainbow_build_palette "$palette_width" "$use_truecolor"
+    }
+
+    do_exit()
+    {
+        exit_st=1
+    }
+
+    trap do_exit TERM INT
+    trap sigwinch WINCH
+    stty -echo
+    printf "\e[?25l"
+    printf "\e[2J"
+
+    sigwinch
+    while ((exit_st <= 0)); do
+        read -r -n 1 -t "$frame_sleep" ch
+        case "$ch" in
+            q|Q)
+                do_exit
+                ;;
+        esac
+
+        row_line=""
+        for ((col = 0; col < term_width; col++)); do
+            idx=$((col - offset))
+            while ((idx < 0)); do
+                ((idx += palette_width))
+            done
+            idx=$((idx % palette_width))
+            row_line+="${RAINBOW_BG_PALETTE[idx]} "
+        done
+        row_line+=$'\e[0m'
+
+        for ((row = 1; row <= term_height; row++)); do
+            printf "\e[%d;1H%b" "$row" "$row_line"
+        done
+
+        ((offset = (offset + 1) % palette_width))
+    done
+
+    printf "\e[0m\e[2J\e[H"
+    printf "\e[?25h"
+    stty echo
+    trap - TERM INT
+    trap - WINCH
+}
+export -f rainbow
 # ------------------------------------------------------------------------------
 
 load_conf "rain"