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Gregg M. Townsend
Department of Computer Science
The University of Arizona
www.cs.arizona.edu/icon/v943/macintosh.htm
Last updated September 22, 2009
Because Mac OS X is based on Unix, it can run Icon. There is no special Macintosh interface, so as a practical matter Icon on the Mac is for those who are comfortable using a Unix shell in a Terminal window.
The command-line interface to Icon is described by Unix
man pages. The icon command executes a program from a
single source file. An Icon program in a simple text file
prog.icn is executed by typing icon
prog.icn. The more general icont command, modeled after the Unix
cc command, supports multiple files, separate
compilation, and other features.
On Intel Macintosh platforms, Icon uses POSIX threads to implement
co-expressions;
and because Apple did not implement anonymous semaphores,
each co-expression creates an open file.
Programs with hundreds of active co-expressions may
abort with a cannot create semaphore system error.
The open file limit can be raised from the typical default of 256
using a limit descriptors n or
ulimit -nS n command, depending on the shell.
For graphics, Icon uses the X Window System, generally called X11 in Macintosh documentation. Beginning with Mac OS 10.5 (Leopard), X11 starts automatically when needed, and no advance preparations are needed. An X11 icon appears in the dock when an Icon graphics program is run and persists innocuously afterward.
Building Icon from source requires the Xcode toolbox, which comes on the OS X installation disc. When installing XCode, be sure to select a custom installation and add X11 to the default set.
Icon is built in a Terminal window. The process is the same as
on other platforms and uses the configuration named
macintosh. See
Building Icon for detailed instructions.
All of the standard tests pass except the io test.
It fails because there is no /etc/motd file on Macintosh Unix.
This is a deficiency of the test and does not indicate a problem with
Icon itself.