#!/usr/bin/env bash
set -euo pipefail

log_message() {
    local level=$1
    local message=$2
    printf "%s: %s\n" "$level" "$message"
}

require_file() {
    local path=$1
    if [ ! -f "$path" ]; then
        log_message ERROR "missing file: $path"
        return 1
    fi
    log_message INFO "found file: $path"
}

printf "demo\n" > input.txt
require_file input.txt
require_file missing.txt || log_message WARN "continuing after check"