dotfiles/.config/zsh/functions/cat-highlight

#!/usr/bin/env zsh
# Highlight cat output with either $CATOPEN or $LESSOPEN. The command needs to
# have %s in it that will be replaced with all input files. Some programs that
# are known to not work will be ignored in $LESSOPEN but not in $CATOPEN.

# Example:
# export CATOPEN="highlight --force --out-format=truecolor --stdout %s"
# alias cat='cat-highlight'

setopt LOCAL_OPTIONS ERR_RETURN PIPE_FAIL

# Check if we are in a terminal and a highlighter is defined
if [[ -t 1 ]] && [[ -n "${CATOPEN}" || -n "${LESSOPEN}" ]]; then
    if [[ -z "${CATOPEN}" ]]; then
        # Programs that won't work with cat
        local -a known_bad=("lesspipe" "pygmentize" "source-highlight")
        for baddy in ${known_bad}; do
            if [[ "${LESSOPEN}" =~ "${baddy}" ]]; then
                \cat "${@}"
                return ${?}
            fi
        done
        local catopen="${LESSOPEN/|/}"
    else
        local catopen="${CATOPEN}"
    fi

    local -a args
    local -a files
    for arg in ${@}; do
        # Filter out file names
        if [[ "${arg[1]}" != "-" ]]; then
            files+=${(q)arg}
        else
            args+="${arg}"
        fi
    done

    eval "${catopen/\%s/${files}} | \cat ${args}"
else
    \cat "${@}"
fi