as-user

#!/usr/bin/env bash

# 1. Interactive mode if no arguments are provided
if [ $# -eq 0 ]; then
    if ! command -v gum &> /dev/null; then
        echo "Error: 'gum' is not installed." >&2
        exit 1
    fi
    
    # Launch a minimal gum input prompt.
    # --prompt "as " creates the illusion you are continuing the command on the same line.
    INPUT=$(gum input --prompt "as " --placeholder "user [do] command..." --width 0)
    
    # Exit gracefully if the user cancels (Ctrl+C / Esc) or submits empty
    [ -z "$INPUT" ] && exit 0
    
    # Print the command back to the terminal in a dim color so it stays in your scrollback
    echo -e "\033[2mas $INPUT\033[0m"
    
    # Parse the input string into positional parameters, respecting quotes
    eval "set -- $INPUT"
fi

# 2. Extract the target user
TARGET_USER="$1"
shift

# 3. Strip the optional "do" keyword if it's the next argument
if [ "$1" = "do" ]; then
    shift
fi

# 4. Ensure a command was actually provided
if [ $# -eq 0 ]; then
    echo "Error: No command specified to run as $TARGET_USER." >&2
    exit 1
fi

# 5. Execute the command
# 'exec' replaces the current script process with the sudo process
exec sudo -u "$TARGET_USER" "$@"