Script portability - Revision history

⚠️HamishBowman: /* Make GRASS shell scripts portable */

2013-04-03T04:32:57Z

Make GRASS shell scripts portable

← Older revision		Revision as of 04:32, 3 April 2013
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	:::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definition of "portable" is perhaps ambiguous.		:::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definition of "portable" is perhaps ambiguous.

⚠️HamishBowman: /* Make GRASS shell scripts portable */

2013-04-03T04:32:38Z

Make GRASS shell scripts portable

← Older revision		Revision as of 04:32, 3 April 2013
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	=== Make GRASS shell scripts portable ===		=== Make GRASS shell scripts portable ===

			For the most part, avoid Bashisms, test with /bin/sh linked to '<tt>dash</tt>', follow the advice in the SUBMITTING files, and have a look at the existing GRASS shell scripts for examples.

			You might also consult the IEEE SUS/POSIX specification to check which features will be available with the BSD power tools, as they are fewer than the GNU power tools. (e.g. 'sed -i' and 'tac' do no exist on Mac OSX)

			Some of what follows only really pertains to really ancient portability issues, and shouldn't be much of an issue for UNIX systems newer than ~ the mid 90s. Please file a bug if you notice that any of the current GRASS scripts fail on exotic or classic UNIX variants, as we aim to be widely portable.


			----

	:::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definition of "portable" is perhaps ambiguous.		:::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definition of "portable" is perhaps ambiguous.

Neteler: +cat

2012-05-05T19:48:42Z

+cat

← Older revision		Revision as of 19:48, 5 May 2012
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	== References ==		== References ==

	* [http://www.novell.com/coolsolutions/feature/11232.html Making Scripts Portable]] by Simon Nattrass		* [http://www.novell.com/coolsolutions/feature/11232.html Making Scripts Portable] by Simon Nattrass
			* [[GRASS and Shell]]

			[[Category: Linking_to_other_languages]]

⚠️Afrigeri at 12:34, 4 May 2012

2012-05-04T12:34:23Z

← Older revision		Revision as of 12:34, 4 May 2012
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	</source>		</source>

	== Arithmetics ==		==== Arithmetics ====

	Expression with $(( ... ))		Expression with $(( ... ))
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	== The $(command) expression versus `command` ==		==== The $(command) expression versus `command` ====

	The $(command) may be supported in many modern Bourne shells but for pure Bourne shells use of `command` is favored, although this method tends to lead to confusion when the backquotes contain the characters $, ` and \. In such cases remember to use the character \ to escape these sequences.		The $(command) may be supported in many modern Bourne shells but for pure Bourne shells use of `command` is favored, although this method tends to lead to confusion when the backquotes contain the characters $, ` and \. In such cases remember to use the character \ to escape these sequences.

⚠️Afrigeri at 12:26, 4 May 2012

2012-05-04T12:26:51Z

← Older revision		Revision as of 12:26, 4 May 2012
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	x=`expr $x + 1`		x=`expr $x + 1`
	</source>		</source>


			== The $(command) expression versus `command` ==

			The $(command) may be supported in many modern Bourne shells but for pure Bourne shells use of `command` is favored, although this method tends to lead to confusion when the backquotes contain the characters $, ` and \. In such cases remember to use the character \ to escape these sequences.


	== References ==		== References ==

	* [http://www.novell.com/coolsolutions/feature/11232.html Making Scripts Portable]] by Simon Nattrass		* [http://www.novell.com/coolsolutions/feature/11232.html Making Scripts Portable]] by Simon Nattrass

⚠️Afrigeri: Created page with "=== Make GRASS shell scripts portable === :::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definiti..."

2012-05-04T12:22:15Z

Created page with "=== Make GRASS shell scripts portable === :::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definiti..."

New page

=== Make GRASS shell scripts portable ===

:::::: Portable shell scripting is something of a black art, since with the evolution and derivation of the UNIX shell, the definition of "portable" is perhaps ambiguous.
:::::: _Simon__Nattrass_

== Guidelines ==

==== Conditionals ====

Conditional with [ ... ] should replaced by __test__

<source lang="bash">
if [ -f foo.c ]
then
...
fi
</source>

as here:

<source lang="bash">
if test -f foo.c
then
...
fi
</source>

== Arithmetics ==

Expression with $(( ... ))
<source lang="bash">
x=$(($x+1))
</source>

are more portable if using __expr__

<source lang="bash">
x=`expr $x + 1`
</source>

== References ==

* [http://www.novell.com/coolsolutions/feature/11232.html Making Scripts Portable]] by Simon Nattrass