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Living Linux

Reminding Yourself With Linux


Sometimes it's useful to give a reminder to yourself -- like to tell you when it's time to get off the computer. Here's a few simple and effective ways to use Linux and open source tools to make reminders for either later in your current login session, or for the next time you log in.

Sending reminders in email

Sending yourself a short email message is often effective for reminding yourself to do something during your next workday or the next time you read email; keeping a message in your INBOX works as a constant reminder to get something done -- provided you don't abuse it and fill your INBOX with lots of these "urgent" mails!

To quickly send an email reminder, give your email address (or just your username on your Linux box, if you check mail there) as an argument to the mail tool. You'll be prompted to give a subject for the message and if that isn't enough space for the reminder, you can write as many lines as you need below it, as the message body text; press Ctrl-d on a line by itself to send the mail.

For example, if your email address is, to send yourself an email reminder:

Subject: Bring files to meeting
Null message body; hope that's ok

The text you type on the Subject: line is displayed as the subject of your email message, and the lines of text you type after that is the body text of the message. In the example, the reminder was typed in the Subject: line and the message body was empty.

Press Ctrl-d on a line alone to end the message; mail then prompts for any email addresses to send a "carbon copy" of the message to; just press enter to ignore it.

There isn't much editing capability in this basic email service -- Ctrl-u erases the current line and Ctrl-c Ctrl-c (yes, press it twice) cancels the message.

Reminding you when you have to leave

Use the leave tool to remind you when you have to leave (you can get either the Debian package or its original NetBSD sources from here at Give as an argument the time, in 24-hour format, when you have to go.

To remind yourself to leave at 8:05pm, type:

leave 20:05 RET

You'll get a reminder printed on your screen five minutes before the given time, one minute before the time, at the time itself and then every minute subsequently until you log off.

Running a command on a timer

The sleep tool does nothing but wait (or "sleep") for the number of seconds specified as an argument. Use this followed by a ; character (the shell command separator) and another command to run that command after the amount of time you specify. This is useful to run a command at a later time during your current session.

You can use it to send you some kind of reminder in a set amount of time -- like the audio output of the saytime tool, which "speaks" the current time in a human voice. It's available as a Debian package or from its Web site at

Since the shell where you type this command will be unusable until the command you give is executed (or until you interrupt it), type this command in a console or window other than one you might be working in.

To ring the bell in thirty seconds, type:

sleep 30; echo -e '\a'

You can also follow the numeric option with a unit:

s	seconds
m	minutes
h	hours
d	days

To announce the time in exactly five minutes, type:

sleep 5m; saytime & 

Next week: connecting your Linux box to the Internet.

Michael Stutz was one of the first reporters to cover Linux and the free software movement in the mainstream press.

Read more Living Linux columns.

Copyright © 2009 O'Reilly Media, Inc.