ANSI Escape Sequences

# All three produce the same result
printf "\033[1mBold\033[0m\n"    # Octal - use this
printf "\x1b[1mBold\x1b[0m\n"    # Hex
printf "\e[1mBold\e[0m\n"        # Bash only

echo -e "\033[31mRed text\033[0m"
echo -e "\033[32mGreen text\033[0m"
echo -e "\033[33;44mYellow on Blue\033[0m"

echo -e "\033[91mBright Red\033[0m"
echo -e "\033[92mBright Green\033[0m"

# Foreground: \033[38;5;Nm (N = 0-255)
# Background: \033[48;5;Nm

echo -e "\033[38;5;208mOrange (208)\033[0m"
echo -e "\033[38;5;39mSky Blue (39)\033[0m"
echo -e "\033[48;5;236;38;5;231mWhite on Dark Gray\033[0m"

# Show all 256 colors
for i in {0..255}; do
    printf "\033[38;5;${i}m%3d\033[0m " "$i"
    [[ $((i % 16)) -eq 15 ]] && echo
done

# Foreground: \033[38;2;R;G;Bm
# Background: \033[48;2;R;G;Bm

echo -e "\033[38;2;255;128;0mTrue Orange\033[0m"
echo -e "\033[38;2;128;0;255mTrue Purple\033[0m"

# Gradient
for i in {0..255..5}; do
    printf "\033[48;2;%d;0;%dm \033[0m" "$i" "$((255-i))"
done
echo

echo -e "\033[1mBold\033[0m"
echo -e "\033[4mUnderline\033[0m"
echo -e "\033[7mReverse\033[0m"

# Combining codes with semicolons
echo -e "\033[1;4;31mBold Underline Red\033[0m"

# Clear screen and home
printf "\033[2J\033[H"

# Position at row 10, column 60
printf "\033[10;60H"

# Multiplication table with positioning
printf "\033[2J\033[H"
for i in {1..10}; do
    for j in {1..10}; do
        printf "\033[%d;%dH%3d" "$i" "$((j*4))" "$((i*j))"
    done
done
printf "\033[12;1H"  # Move below table

# Clear screen and home (common combo)
printf "\033[2J\033[H"

# Clear line and rewrite (for progress)
printf "\033[2K\rProcessing..."

# Hide/show cursor (for animations)
printf "\033[?25l"   # Hide
printf "\033[?25h"   # Show

# Color definitions
readonly RED='\033[31m'
readonly GREEN='\033[32m'
readonly YELLOW='\033[33m'
readonly BLUE='\033[34m'
readonly BOLD='\033[1m'
readonly RESET='\033[0m'

# Status functions
info()    { printf "${BLUE}[INFO]${RESET}  %s\n" "$1"; }
success() { printf "${GREEN}[OK]${RESET}    %s\n" "$1"; }
warn()    { printf "${YELLOW}[WARN]${RESET}  %s\n" "$1" >&2; }
error()   { printf "${RED}[FAIL]${RESET}  %s\n" "$1" >&2; }

# Usage
info "Starting backup process"
success "vault-01 backup complete"
warn "Certificate expires in 7 days"
error "bind-01 unreachable"

# Simple banner
banner() {
    local msg="$1"
    local color="${2:-34}"  # Default blue
    printf "\033[1;${color}m=== %s ===\033[0m\n" "$msg"
}

banner "Starting Deployment"
banner "Warning" 33     # Yellow
banner "Error" 31       # Red

# Box banner with Unicode
box_banner() {
    local msg="$1"
    local len=${#msg}
    local border=$(printf '═%.0s' $(seq 1 $((len + 4))))

    printf "\033[1;36m╔%s╗\n║  %s  ║\n╚%s╝\033[0m\n" \
        "$border" "$msg" "$border"
}

box_banner "Production Deploy"

progress_bar() {
    local current=$1
    local total=$2
    local width=40
    local percent=$((current * 100 / total))
    local filled=$((current * width / total))

    printf "\r["
    for ((i=0; i<width; i++)); do
        if ((i < filled)); then
            printf "\033[42m \033[0m"   # Green
        else
            printf "\033[100m \033[0m"  # Gray
        fi
    done
    printf "] %3d%%" "$percent"
}

printf "\033[?25l"   # Hide cursor
for i in {0..100}; do
    progress_bar "$i" 100
    sleep 0.02
done
printf "\n\033[?25h" # Show cursor

# Simple multiplication table
awk 'BEGIN {
    for (i=1; i<=10; i++) {
        for (j=1; j<=10; j++)
            printf "%4d", i*j
        print ""
    }
}'

# With color highlighting (perfect squares green)
awk 'BEGIN {
    for (i=1; i<=10; i++) {
        for (j=1; j<=10; j++) {
            val = i * j
            if (int(sqrt(val))^2 == val)
                printf "\033[32m%4d\033[0m", val
            else
                printf "%4d", val
        }
        print ""
    }
}'

# Colorize log files by level
colorize_logs() {
    awk '
    /ERROR|FAIL|CRITICAL/ { printf "\033[31m%s\033[0m\n", $0; next }
    /WARN|WARNING/        { printf "\033[33m%s\033[0m\n", $0; next }
    /INFO|NOTICE/         { printf "\033[34m%s\033[0m\n", $0; next }
    /DEBUG|TRACE/         { printf "\033[90m%s\033[0m\n", $0; next }
    /SUCCESS|OK/          { printf "\033[32m%s\033[0m\n", $0; next }
    { print }
    '
}

# Usage
tail -f /var/log/app.log | colorize_logs

# Highlight IPs in cyan
cat /etc/hosts | awk '{
    gsub(/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/, "\033[36m&\033[0m")
    print
}'

# Highlight arbitrary pattern
highlight() {
    local pattern="$1"
    awk -v p="$pattern" '{
        gsub(p, "\033[1;33m&\033[0m")
        print
    }'
}

cat config.yml | highlight "server"

# Status table with conditional coloring
echo "vault-01 10.50.1.30 up
ise-01 10.50.1.20 up
bind-01 10.50.1.90 down" | awk '
BEGIN {
    printf "\033[1;4m%-15s %-12s %-8s\033[0m\n", "Hostname", "IP", "Status"
}
{
    color = ($3 == "up") ? "\033[32m" : "\033[31m"
    printf "%-15s %-12s %s%-8s\033[0m\n", $1, $2, color, $3
}'

# Dashboard with CPU/memory coloring
ps aux --no-headers | awk '
BEGIN {
    printf "\033[1m%-10s %8s %8s %s\033[0m\n", "USER", "CPU%", "MEM%", "COMMAND"
}
NR <= 10 {
    cpu_color = ($3 > 50) ? "\033[31m" : "\033[32m"
    printf "%-10s %s%8.1f\033[0m %8.1f %s\n", $1, cpu_color, $3, $4, $11
}'

use_color() {
    [[ -t 1 ]] && [[ "${TERM}" != "dumb" ]] && [[ -z "${NO_COLOR:-}" ]]
}

if use_color; then
    RED='\033[31m'
    GREEN='\033[32m'
    RESET='\033[0m'
else
    RED=''
    GREEN=''
    RESET=''
fi

# Now use $RED, $GREEN, $RESET throughout script