Monitor URL HTTP Status Shell Script

Teams bookmark a monitor URL HTTP status shell script when UptimeRobot is overkill but curl -I in cron is enough — this version reads a URL list, records codes, and fails for Nagios-style exits.

What this script does

Reads URLs from file or single argument
Uses curl -fsS with connect and max time
Captures HTTP code with -w '%{http_code}'
Optional expected code (default 200)
Exit 1 if any URL fails

Prerequisites

curl
Outbound HTTPS
Optional mail or webhook for alerts

Step 1: Save the script

sudo nano /usr/local/bin/http-status-check.sh
sudo chmod +x /usr/local/bin/http-status-check.sh

Step 2: Full script (scroll to read)

http-status-check.sh

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

CONNECT="${CONNECT_TIMEOUT:-10}"
MAX="${MAX_TIME:-30}"
EXPECT="${EXPECT_CODE:-200}"
LOG="/var/log/http-status.log"
fail=0

log(){ echo "[$(date '+%F %T')] $*" | tee -a "$LOG"; }

check_one(){
  local url="$1"
  local code
  code=$(curl -fsS -o /dev/null -w '%{http_code}' --connect-timeout "$CONNECT" --max-time "$MAX" "$url" 2>/dev/null) || code="000"
  if [[ "$code" == "$EXPECT" ]]; then
    log "OK $code $url"
    return 0
  fi
  log "FAIL $code $url (expected $EXPECT)"
  fail=1
  return 1
}

if [[ $# -eq 1 && -f "$1" ]]; then
  while IFS= read -r url || [[ -n "$url" ]]; do
    [[ -z "$url" || "$url" =~ ^# ]] && continue
    check_one "$url" || true
  done <"$1"
elif [[ $# -ge 1 ]]; then
  for url in "$@"; do
    check_one "$url" || true
  done
else
  echo "usage: http-status-check.sh URL [URL...]" >&2
  echo "       http-status-check.sh urls.txt" >&2
  exit 2
fi

exit "$fail"

Scroll inside the box to read the full script.

Step 3: Configure settings

Different from uptime monitor script — lighter single-URL focus
JSON APIs: API health script
Retries: curl retry script

Shell script checking HTTP status with curl

Step 4: Test manually

./http-status-check.sh https://example.com

./http-status-check.sh /etc/monitor-urls.txt

Schedule with cron

sudo crontab -e

Add:

*/5 * * * * /usr/local/bin/http-status-check.sh /etc/monitor-urls.txt >> /var/log/http-status.log 2>&1

Monitor URL HTTP Status Shell Script (curl Exit Codes, Cron)