diff options
| -rw-r--r-- | README.md | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/README.md b/README.md new file mode 100644 index 0000000..3fc8a96 --- /dev/null +++ b/README.md @@ -0,0 +1,62 @@ +# Ordinary Daemon + +This is a simple UNIX daemon implemented in C that logs uptime and signal statistics to both a file and syslog. + +## Features + +- Runs as a background daemon process. +- Handles the following signals: + - **SIGUSR1** — increments an internal counter and triggers logging. + - **SIGALRM** — triggers logging and re-arms itself every 300 seconds. +- Logs: + - Time elapsed since the daemon started. + - PID of the daemon process. + - Number of `SIGUSR1` signals received. +- Writes logs to: + - `/tmp/ordinary_daemon.log` (text file) + - System log (via `syslog` with facility `LOG_USER`). +- Detaches from the terminal, redirects standard streams to `/dev/null`. +- Double-fork daemonization to ensure it is fully detached from the controlling terminal. + +## How It Works + +1. On startup, the process daemonizes itself: + - Closes standard file descriptors. + - Changes working directory to `/`. + - Creates a new session (`setsid()`). + - Forks twice to prevent acquiring a controlling terminal. +2. Opens `/tmp/ordinary_daemon.log` for writing. +3. Sets up signal handlers for `SIGUSR1` and `SIGALRM`. +4. Starts a 300-second alarm to trigger periodic logging. +5. Waits in an infinite loop (`pause()`), writing logs when a signal is received. + +## Usage + +Compile: + +```bash +git clone https://git.scratko.xyz/typical-daemon-process +cd typical-daemon-process +gcc -o ordinary_daemon daemon.c +``` +Run: +```bash +./ordinary_daemon +``` +Send signals: +```bash +kill -USR1 <pid> # increment counter and log immediately +kill -ALRM <pid> # log immediately and restart 300s timer +``` +View log file: +```bash +cat /tmp/ordinary_daemon.log +``` + +View syslog output (example for systemd-based systems): +```bash +journalctl -t "ordinary daemon" +``` + +## Example Log Entry +time spent (in sec): 120.50 pid: 12345 SIGUSR1: 3 |