feat: enhance input handling script with color support and help option

Add dynamic color support to the script for better user feedback,
including info, warning, and success messages. Introduce a help
option (-h/--help) to guide users on script usage. Improve input
handling by integrating `rlwrap` and `bat` for enhanced interactivity
and fallback to `cat` when unavailable. Update exit codes for better
error signaling.

These changes improve the script's usability, interactivity, and
user experience by providing clear feedback and robust input handling.
The help option ensures users can easily understand the script's
functionality.

Signed-off-by: Marcelo Borges <me@marceloborges.dev>

scripts/paste

@@ -1,19 +1,72 @@
 #!/bin/sh
 
-# Use a friendly blue color for messages
-echoinfo() { printf "\033[1;36m%s\033[0m\n" "$@" >&2; } # Cyan text
+# Check if the terminal supports colors
+if tput setaf 1 >/dev/null 2>&1; then
+  COLOR_INFO="$(tput setaf 4)"    # Bright Blue for general info
+  COLOR_WARN="$(tput setaf 3)"    # Yellow for warnings
+  COLOR_SUCCESS="$(tput setaf 2)" # Green for success
+  COLOR_RESET="$(tput sgr0)"
+else
+  COLOR_INFO=""
+  COLOR_WARN=""
+  COLOR_SUCCESS=""
+  COLOR_RESET=""
+fi
+
+# Function to print messages with appropriate colors
+echoinfo() {
+  printf "%s%s%s\n" "$COLOR_INFO" "$1" "$COLOR_RESET" >&2
+}
+
+echowarn() {
+  printf "%s%s%s\n" "$COLOR_WARN" "$1" "$COLOR_RESET" >&2
+}
+
+echosuccess() {
+  printf "%s%s%s\n" "$COLOR_SUCCESS" "$1" "$COLOR_RESET" >&2
+}
+
+# Display help message
+show_help() {
+  printf "Usage: %s [OPTION]\n" "$0"
+  printf "Capture input and echo it back to stdout.\n\n"
+  printf "Options:\n"
+  printf "  -h, --help    Show this help message and exit\n\n"
+  printf "Example:\n"
+  printf "  %s              # Capture input interactively\n" "$0"
+  printf "  echo 'Hello' | %s  # Capture input from a pipe\n" "$0"
+  exit 0
+}
 
-if [ -t 0 ]; then # Check if input is from a terminal (not piped)
-  echoinfo "📋 Input content and press Enter (Ctrl+D to finish):"
-  input_content=$(cat) # Capture full multi-line input
+# Check for help option
+case "$1" in
+-h | --help) show_help ;;
+esac
+
+if command -v bat >/dev/null 2>&1; then
+  CAT="bat"
+else
+  CAT="cat"
+fi
+
+# Check if rlwrap is available
+if command -v rlwrap >/dev/null 2>&1; then
+  RLWRAP="rlwrap $CAT"
 else
-  input_content=$(cat) # Read from pipe
+  RLWRAP="$CAT"
+fi
+
+if [ -t 0 ]; then # Interactive mode
+  echoinfo "📋 Enter input and press Enter (Ctrl+D to finish):"
+  input_content=$($RLWRAP)
+else # Piped input
+  input_content=$($CAT)
 fi
 
 if [ -z "$input_content" ]; then
-  echoinfo "⚠️  No input received!"
-  exit 0
+  echowarn "⚠️  No input received!"
+  exit 1
 fi
 
-echoinfo "✅ Echoing the input to stdout!"
-echo "$input_content"
+echosuccess "✅ Echoing the input to stdout!"
+printf "%s\n" "$input_content"