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diff --git a/www/blog/2019-02-17/index.html b/www/blog/2019-02-17/index.html deleted file mode 100644 index 1b04fb5..0000000 --- a/www/blog/2019-02-17/index.html +++ /dev/null @@ -1,184 +0,0 @@ -<!DOCTYPE html> -<html lang="en"> -<head> - <meta charset="utf-8"> - <meta name="generator" - content="HTML Tidy for HTML5 for Linux version 5.7.45"> - <title>senders.io - Blog</title> - <link rel='stylesheet' - type='text/css' - href='/index.css'> - <meta name="viewport" - content="width=device-width, initial-scale=1"> -</head> -<body> - <div id='header'> - <a class='title' - href='/'>senders.io</a> - <nav> - <a href="/resume">Resume</a> <a href="/blog">Blog</a> <a href= - "https://github.com/s3nd3r5">Github</a> - </nav> - </div> - <div id='body'> - <article> - <h2>Venturing back into C</h2> - <p>For the past two weeks or so I have been diving back into C - programming. I've found it to be a very fun and refreshing experience - coming off of a slog of Java 11 updates at work. I've found comfort - in its simplicity and frustrations in my "I can do this without an - IDE" mindset.</p> - <p>I started C programming in College during a 8 AM course of which all I - can remember is that it was at 8 AM. I loved programming in C, dealing - with memory, pointers, no strings, structs, no strings, linking, no - strings. It was a really interesting difference from the web and Java - programming I had done previously. Obviously the lack of the - "string" type made things interesting and initially a challenge - for me back then. In my most recent endevour I found <code class= - 'inline'>char *</code> to be perfectly suitable for every case I came - across. It was usually a separate library that was failing me, not a - fixed char array. This was mostly due to the types of programs I was - writting in college were text adventures where all of what I did was - using strings. And my lack of understanding of what was actually - happening in C was really what was causing all the issues.</p> - <h3>The Project</h3> - <p>I started working on an application I had been meaning to develop - called <a href= - 'https://github.com/s3nd3r5/reminder'><b>reminder.d</b></a>. This daemon - would monitor for reminder notifications I would send via a CLI. It queue - them up based on some time set to send the notification. I ended up - writing both the CLI and the daemon in this past week, both in C.</p> - <h4>The Beginning</h4> - <p>This project started with an outline (as a README) which I think was - the reason this ended up as an actually successful project. I had been - thinking about this for a long time, and had begun using a calendar to - keep track of long term reminders/dates etc. First, I outlined the - architecture "how would I actually do want to send myself - remidners". Since half my day is spent infront of a computer, with a - terminal open or at least two keystrokes away, a CLI would do the trick. - Then how do I actually send myself notifications... writing them down. So - I can use the CLI to write to a file and have a daemon pick up the - changes and notify me once it hits the desired time posted.</p> - <h4>The CLI</h4> - <p>The CLI <b>remindme</b> took in messages and appened them to a file. - This file would be monitored by the daemon later on. Each reminder - consisted of three parts:</p> - <ul> - <li><i>Message</i> - The body of the notification.</li> - <li><i>Time</i> - This is either a datetime or a period for when the - notification should send.</li> - <li><i>Flag</i> - The Flag was set by the CLI when written to the file, - this marks the status of the reminder</li> - </ul>After a notification is written the daemon will pick up the - notification and notify if the time set is now/past. - <h4>The Daemon</h4> - <p>The Daemon <b>reminder-daemon</b> opened and tailed a file at - <i>/usr/local/etc/reminder.d/$USER.list</i>. It would tail the file - monitoring any incoming lines parsing them into reminders. The syntax of - the reminder is <code class='inline'>FLAG EPOCHSEC MESSAGE</code> . - Tokenizing on spaces it was then added to a linked-list sorted by time. - Every second it checks the file for any new lines, adding reminders as - they come in, then check the head of the list. If the reminder at the - head is ready to be notified the daemon pops it off the list and sends - the notification. After a notification is sent successfully the daemon - modifies that line in file updating its <code class='inline'>FLAG</code> - to 'd'. This is so when the daemon starts back up it skips the - reminder. Notifications are sent via <i>libnotify</i>: <code class= - 'inline'>Reminder - $DATETIME</code> with the message body. They are also - set to last until dismissed manually, this way if were to walk away, once - I sat down I'd see the stale reminder waiting.</p> - <h4>Future Plans for Reminder.d</h4> - <p>Having a system to create and send myself notifications is incredibly - useful but having them limit to just the computer I sent them on makes - them a very limited. I have been using them at work for the last few days - and its nice to be able to tell myself to remeber to email a person after - lunch. But I would like to be able to tell myself things later in the - day. I have planned since the beginning to have a remote server I can - sync the reminders through. In addition having an application running on - my phone that also gets and sets reminders.</p> - <p>Remote syncing would change entirely how I deal with reminders in the - file.</p> - <pre> -<code> - struct remnode { - long fileptr; - struct reminder* reminder; - struct remnode* next; - }; - </code></pre> - <p>Is currently the struct I use to keep track of the reminders. - <code class='inline'>fileptr</code> is the line of the file where the - reminder is, so I can <code class='inline'>fseek</code> back to the - location and overwrite its flag. I cannot currently think of a way to - keep the files perfectly identical without introducing countless - edgecases. What I do think might work is providing some form of UUID. - When a remote pull tells the systems daemon that a notification has been - cleared it can mark it by ID. Right now the fileptr is effectively its - ID, but that will not work anymore. A composite key of the daemons own id - (generated at install?) with a new ID of each incoming message would help - ensure uniqueness across ID generations across multiple systems.</p> - <h3>What I've learned</h3> - <p>First off, I probably could've done this in bash. With - <code class='inline'>date notify-send git awk cron</code> and a few other - useful commands I could very easily keep track of file changes and push - notifications at a certain time. But seeing as I scrap together bash - scripts all the time I though C would make things more fun.</p> - <p>Writing manpages was the probably the most fun I had working on the - project. They have a simple elegance to them, similar to C. That being - said you could FEEL the age of the language. Every single decision is - there to make things simple to parse. Even compared to modern markup the - explicit direct nature of the language made it so easy to learn. Every - tag served a specific purpose and each objective I had had a flag to do - it.</p> - <pre><code> -.TH REMINDME 1 -.SH NAME - remindme \- Send yourself reminders at a specific time on one or more devices -.SH SYNOPSIS -.B remindme -[\fB\-t\fR \fITIME\fR] -[\fB\-\-at \fITIME\fR] -[\fB\-i\fR \fIPERIOD\fR] -[\fB\-\-in\fR \fIPERIOD\fR] - </code> - </pre> - <p>Libnotify was insanely easy to work with, from a programming - perspective.</p> - <pre><code> - NotifyNotification *notif = notify_notification_new(title, rem->message, "info"); - notify_notification_set_app_name(notif, APP_NAME); - notify_notification_set_timeout(notif, NOTIFY_EXPIRES_NEVER); - - GError* error = NULL; - gboolean shown = notify_notification_show(notif, &error); - </code> - </pre> - <h3>In closing</h3> - <p>Overall, this was an extremely fun first week of engineering. I look - forward to what I am able to do syncing and sending notifications on - android.</p> - <p>For the zero people reading, grab a beer and outline your project. - Full through. Think about the how, then write it down. Don't worry - about getting in the weeds of how to write a manfile, thats what is fun - about programming. I thought I botched my debian/sid environment - uninstalling and reinstalling a notification daemon. Infact I think its - caused me to take a stance on the whole systemd thing. Either way, start - a private repo (they're free now) write a README and a LICENSE file - and iterate on the README until you realize "oh shit this is - something I can do". Then do it. This project still needs some work, - but for an MVP, its actually done. And now I can dive in the deep end of - trying to actually make it easy to setup on a fresh PC. Or dive into - modern android development and server syncing...</p> - </article> - <div id='footer'> - <i>February 17, 2019</i> - </div> - <div id='copyright'> - © 2023 senders dot io - <a rel="license external noopener noreferrer" - target="_blank" - href="https://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA - 4.0</a> unless otherwise noted. - </div> - </div> -</body> -</html> |