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Running gawk on the Atari ST

An executable version of gawk should be placed, as usual, anywhere in your PATH where your shell can find it.

While executing, the Atari version of gawk creates a number of temporary files. When using gcc libraries for TOS, gawk looks for either of the environment variables, TEMP or TMPDIR, in that order. If either one is found, its value is assumed to be a directory for temporary files. This directory must exist, and if you can spare the memory, it is a good idea to put it on a RAM drive. If neither TEMP nor TMPDIR are found, then gawk uses the current directory for its temporary files.

The ST version of gawk searches for its program files, as described in The AWKPATH Environment Variable. The default value for the AWKPATH variable is taken from DEFPATH defined in Makefile. The sample gcc/TOS Makefile for the ST in the distribution sets DEFPATH to ".,c:\lib\awk,c:\gnu\lib\awk". The search path can be modified by explicitly setting AWKPATH to whatever you want. Note that colons cannot be used on the ST to separate elements in the AWKPATH variable, since they have another reserved meaning. Instead, you must use a comma to separate elements in the path. When recompiling, the separating character can be modified by initializing the envsep variable in unsupported/atari/gawkmisc.atr to another value.

Although awk allows great flexibility in doing I/O redirections from within a program, this facility should be used with care on the ST running under TOS. In some circumstances, the OS routines for file-handle pool processing lose track of certain events, causing the computer to crash and requiring a reboot. Often a warm reboot is sufficient. Fortunately, this happens infrequently and in rather esoteric situations. In particular, avoid having one part of an awk program using print statements explicitly redirected to /dev/stdout, while other print statements use the default standard output, and a calling shell has redirected standard output to a file.

When gawk is compiled with the ST version of gcc and its usual libraries, it accepts both / and \ as path separators. While this is convenient, it should be remembered that this removes one technically valid character (/) from your file name. It may also create problems for external programs called via the system function, which may not support this convention. Whenever it is possible that a file created by gawk will be used by some other program, use only backslashes. Also remember that in awk, backslashes in strings have to be doubled in order to get literal backslashes (see Escape Sequences).