Getting the at scheduler working

posted 2015.12.27 [Mac OS 10.10.5 "Yosemite"]

(This note was adapted from a discussion on StackExchange.)

By default, the Mac's atrun daemon is disabled, which means that the handy event scheduler at won't do anything. Here's how to get it working:

1. Edit the atrun daemon's plist:

   % sudo vim /System/Library/LaunchDaemons/com.apple.atrun.plist

   ad change these two lines

   <key>Disabled</key> <true/>

   to

   <key>Disabled</key> <false/>

2. Unload the old plist and reload the new one:

   % sudo launchctl unload -F /System/Library/LaunchDaemons/com.apple.atrun.plist % sudo launchctl load -F /System/Library/LaunchDaemons/com.apple.atrun.plist

3. Test it by invoking at and giving it a simple command to execute:

   % at now echo "Hello world." ^D job 18 at Sun Dec 27 17:14:31 2015 %

   In a few moments you'll receive an email from atrun containing the output of your queued command (i.e., an email containing "Hello world." in the message body).
4. To see what jobs are in the queue, type atq.

Caveat #1: Keep in mind that at executes its commands within the bash shell. It's always a good idea to test your command in a bash shell before entrusting it to at.

Caveat #2: If you're like most people, you probably don't use the Mac's built-in *nix mail program that at uses. But you can easily have at's emails forwarded to the email address of your choice. To do this, open (or create) the .forward file in your home directory:

% vim ~/.forward

xyz@gmail.com

You can have more than one address here — just separate them with commas.

Send email from command line via Gmail SMTP in Mac OS X Yosemite

posted 2015.03.05; updated 2015.03.22 [OS 10.10.2 Yosemite]

If you want to send email directly from the Terminal command line, or from php's mail() function, you have to configure postfix to use an external SMTP server. There are many excellent tutorials and blogs out there describing how to do this, but because Apple tinkers with postfix with each major OS upgrade, these instructions can quickly become obsolete. It took me several hours to put all the pieces together and get it to work on OS X 10.10

The following instructions, gleaned and adapted from a number of blogs, tutorials, and readers' comments,[1] summarize how I got postfix to work with Gmail on OS X 10.10.2.

1. If you don't already have a Gmail account, get one. You'll need the login credentials for that account to access Google's SMTP servers.
2. Open a Terminal window and edit the postfix password file:

   % sudo vim /etc/postfix/sasl_passwd

   Add the following line to this file:

   smtp.gmail.com USERNAME@gmail.com:PASSWORD

   where USERNAME and PASSWORD are your Gmail login credentials. Save the file and quit.

3. Make the password file readable only to root:

   % sudo chmod og-rw /etc/postfix/sasl_passwd

4. Edit the main postfix config file:

   % sudo cp /etc/postfix/main.cf /etc/postfix/main.cf.orig ⇐ play safe: save a copy of the original! % sudo vim /etc/postfix/main.cf

   Add the following lines to the end of the file:

   mail_owner = _postfix setgid_group = _postdrop relayhost = smtp.gmail.com:587 # Enable SASL authentication in the Postfix SMTP client. smtp_sasl_auth_enable=yes smtp_sasl_password_maps=hash:/etc/postfix/sasl_passwd smtp_sasl_security_options= smtp_sasl_mechanism_filter = plain ⇐ OS X 10.10 Yosemite needs this line # Enable Transport Layer Security (TLS), i.e. SSL. smtp_use_tls=yes smtp_tls_security_level=encrypt tls_random_source=dev:/dev/urandom

   Save the file and quit.

5. Restart postfix:

   % sudo postmap /etc/postfix/sasl_passwd % sudo postfix stop % sudo postfix start % sudo postfix reload

6. Test everything by sending an email from the command line:

   % date | mail YOUREMAILADDRESS

   where YOUREMAILADDRESS is, of course, your email address. In a moment you should receive an email at that address that contains no subject, and simply the date in its body. If this works, you're done!

7. If you don't receive an email, check the last few lines of your postfix server log:

   % tail -f /var/log/mail.log

See also this tech note: "Sending email from PHP scripts"

How to install wget on a Mac

posted 2013.12.18 [Mac OS 10.7.5 "Lion"]

1. Download the wget source code from ftp.gnu.org. Choose the file with the highest version number, and whose filename ends in .tar.gz (e.g., wget-1.14.tar.gz).
2. Double-click the downloaded archived file to unarchive it into a folder. A folder named something like wget-1.14 will be created.
3. Move the folder (e.g., wget-1.14) to wherever you keep your source files (e.g., in ~/src). From here on, we'll assume that this folder resides at ~/src/wget-1.14
4. Type the following commands in a Terminal window:

   % cd ~/src/wget-1.14 % ./configure --with-ssl=openssl % make % sudo install % rehash

   (The --with-ssl option allows you to build wget without having to install the GNUTLS package.)

5. Type

   % wget --help

   and you're off to the races!

No audio from some websites

posted 2010.01.25

Problem: Sometimes I don’t hear any sound from Safari or Firefox while playing content from multimedia websites (e.g., YouTube). Curiously, sites that stream QuickTime files come through just fine; it’s just the embedded video files that don’t produce sound.

Cause: If you work with lots of sound apps (SoundHack, Audacity, etc.), one of them may have inadvertently munged some of the Mac’s core audio settings.

Fix:

1. Open Audio MIDI Setup (/Applications/Utilities/), then check the Audio Output setting.
2. Change the Audio Output setting to 44100.0 Hz.
3. Quit Audio MIDI Setup.
4. Restart the app (e.g., Firefox).

See the Apple tech article "Mac OS X: No audio from certain multimedia content" for more details.

How to setup virtual hosts

posted 2008.02.26; updated 2015.04.30 [OS 10.10.2 Yosemite]

The procedure for setting up virtual hosts seems to change slightly with each update of OS X. Here's how I did it for Yosemite.

1. Open a Terminal window and type: sudo vi /etc/extra/httpd-vhosts.conf and enter your password, if asked.
2. Insert the following lines at the end of the file

   <VirtualHost *:80> ServerName project1 DocumentRoot /Users/yourname/Sites/project1 ErrorLog "/private/var/log/apache2/project1-localsite-error_log" CustomLog "/private/var/log/apache2/project1-localsite-access_log" common </VirtualHost>

   If you have more sites, simply add more <VirtualHost> blocks as needed, in the same format.

3. Save and quit (type :wq).
4. Edit your hosts file (type sudo vi /etc/hosts) and insert the following lines at the end:

   127.0.0.1 project1

   If you have more sites, just add more lines in that format. For example:

   127.0.0.1 project2

5. Save and quit (type :wq).
6. Restart Apache: sudo apachectl graceful
7. Now point your browser to http://project1 and the site located at /Users/yourname/Sites/project1 will load.

How to make system files and folders visible

posted 2007.02.28

By default, the Finder hides root-level directories (/usr, /lib, /etc, etc.,) from dialog boxes, which makes it hard to navigate there. Here’s one trick to make them accessible to the Finder’s — and every app’s — dialog boxes.

1. In the Finder, type "shift command G" ("Go to folder").
2. Type "/usr" (for example) and click "Go".
3. Drag the tiny "usr" icon at the top of the window over to the sidebar.

Voilà! From now on, /usr will always be easily accessible to "open" and "save" dialog boxes in all your apps.

To make every file visible to the Finder — including those that begin with a ".", such as .htaccess or .login — issue the following command at the Terminal:

% defaults write com.apple.finder AppleShowAllFiles TRUE; killall Finder

To make those ’invisible’ files go away again, do this:

% defaults write com.apple.finder AppleShowAllFiles FALSE; killall Finder

I like to be able to turn those invisible files on and off easily, so I have a couple of aliases in my ~/.alias file:

% alias dot+ "defaults write com.apple.finder AppleShowAllFiles TRUE; killall Finder" % alias dot- "defaults write com.apple.finder AppleShowAllFiles FALSE; killall Finder"

Or you could use a third-party utility such as TinkerTool.

AppleScript: "Press Run to run this script"

posted 2007.02.25

If you write your own AppleScripts, you’ve probably seen an alert box pop up with this message when you try to run your script:

Press Run to run this script, Quit to quit.

Fix: When you save the script as an app using "Save as...", look at the save options carefully. Make sure the "Startup screen" checkbox is unchecked before saving.

Works for me.

Firefox mis-renders some TrueType italics

posted 2007.04.04

Problem: Firefox (2.0.0.3; Mac OS 10.4.9) renders some fonts (Gentium, for example) such that italicized text overwrites the preceding character or two. The result can be an unintelligible mess (shown here in Gentium font):

Safari and IE (Mac) don’t have this problem.

Cause: Firefox seems to have difficulty in rendering TrueType fonts in italic.

Fix: Hunt down and remove any TrueType versions of the offending font in all four of the possible font folders (~/Library/Fonts, /Library/Fonts/, /Network/Library/Fonts/, and /System/Library/Fonts/ — see "Mac OS X: Font Locations and Their Purposes"). Re-install the "font suitcase" version of the font (i.e., drop the font suitcase into one of those four font folders). Restart Firefox.

Windows and buttons have annoying borders

posted 2007.05.28

Problem:

Cause: You probably accidentally turned on VoiceOver, by hitting cmd-F5.

Fix: cmd-F5 toggles VoiceOver on/off. Failing that, go to System Preferences → Universal Access and turn off VoiceOver.

How to install GD into PHP on Leopard

posted 2008.10.20

A tutorial for the easiest possible way to install GD into PHP on Leopard: Adding GD library for Mac OS X Leopard.

First, some background... Mac OS X 10.5 (Leopard) ships with PHP 5.2 installed, but without the useful GD graphics library. Most of the GD installation tutorials I found on the web involve an intimidating series of steps that require downloading a bunch of supporting libraries, compiling them, then re-compiling PHP. Although Kénior’s tutorial Adding GD Library for Mac OS X Leopard seems to have worked for many people, it never quite worked for me; after many careful tries, I kept getting Apache errors (as seen in /var/error/apache2/error_log) that prevented GD from successfully loading:

After much hair-pulling, I finally found that wonderfully simple tutorial. It calls for simply (1) downloading a fresh PHP installation that already has GD compiled-in, and (2) using it to replace the existing PHP folder in /usr/local. I had PHP up and running with GD in about one minute.

What could be simpler?

Common glyphs in ASCII and HTML (sorted by HTML code)

posted 2001.01.01

Common glyphs in ASCII and HTML (sorted by Mac code)

posted 2001.01.01

Sources:

• Griswold, Ralph E. and Madge T. Griswold, The Icon Programming Language, 3rd ed. Peer to Peer, 1997, as quoted in www.cs.arizona.edu by Ralph Griswold, University of Arizona.
• "Character entity references in HTML 4" (Section 24 of HTML 4.01 Specification: W3C Recommendation), by the World Wide Web Consortium; 1999.12.24; www.w3.org.
• "ASCII Extended Character Set, Macintosh", by Dawn Rorvik, Evergreen State College; 2003.05.20; www.evergreen.edu.

See also:

• Wikipedia's complete list of XML and HTML character entities