colorecho

#!/bin/bash
set -eu

usage() {
    cat >&2 <<EOM
usage: $(basename "$0") [--dim] COLOR [options] [STRING...]

Echo STRING(s) to standard output. If standard output is a TTY, also echo the
standard TTY escapes for COLOR to print colorized output.

See \`help echo\` in bash for options passed to echo.

Options:

    --dim     Don't echo bold colors

Known colors, (aliases):
    black (gray, grey)
    red
    green
    yellow
    blue
    magenta (purple, violet)
    cyan
    white

EOM
}

bold=1
if [ $# -ge 1 ] && [ "$1" = "--dim" ]; then
    bold=0
    shift
fi

if [ $# -lt 1 ]; then
    usage
    exit 1
fi
case "$1" in
    black|gray|grey)       fg=30 ;;
    red)                   fg=31 ;;
    green)                 fg=32 ;;
    yellow)                fg=33 ;;
    blue)                  fg=34 ;;
    magenta|purple|violet) fg=35 ;;
    cyan)                  fg=36 ;;
    white)                 fg=37 ;;
    *)
        usage
        echo >&2 "Unknown color: $1"
        exit 1
        ;;
esac
shift

if [ -t 1 ]; then
    echo -ne "\033[$bold;${fg}m"
fi

echo "$@"

if [ -t 1 ]; then
    echo -ne "\033[m"
fi