Roland Ver. 4.5 Información técnica descargar pdf (Pagina 154)

144 GNU make

• The automatic variable $^ containing a list of all prerequisites of the current target.

We did not invent this, but we have no idea who did. See Section 10.5.3 [Automatic

Variables], page 120. The automatic variable $+ is a simple extension of $^.

• The “what if” ﬂag (‘-W’ in GNU make) was (as far as we know) invented by Andrew

Hume in mk. See Section 9.3 [Instead of Executing Recipes], page 101.

• The concept of doing several things at once (parallelism) exists in many incarnations

of make and similar programs, though not in the System V or BSD implementations.

See Section 5.3 [Recipe Execution], page 44.

• A number of diﬀerent build tools that support parallelism also support collecting output

and displaying as a single block. See Section 5.4.1 [Output During Parallel Execution],

page 47.

• Modiﬁed variable references using pattern substitution come from SunOS 4. See

Section 6.1 [Basics of Variable References], page 59. This functionality was provided in

GNU make by the patsubst function before the alternate syntax was implemented for

compatibility with SunOS 4. It is not altogether clear who inspired whom, since GNU

make had patsubst before SunOS 4 was released.

• The special signiﬁcance of ‘+’ characters preceding recipe lines (see Section 9.3 [In-

stead of Executing Recipes], page 101) is mandated by IEEE Standard 1003.2-1992

(POSIX.2).

• The ‘+=’ syntax to append to the value of a variable comes from SunOS 4 make. See

Section 6.6 [Appending More Text to Variables], page 66.

• The syntax ‘archive(mem1 mem2...)’ to list multiple members in a single archive ﬁle

comes from SunOS 4 make. See Section 11.1 [Archive Members], page 129.

• The -include directive to include makeﬁles with no error for a nonexistent ﬁle comes

from SunOS 4 make. (But note that SunOS 4 make does not allow multiple makeﬁles

to be speciﬁed in one -include directive.) The same feature appears with the name

sinclude in SGI make and perhaps others.

• The != shell assignment operator exists in many BSD of make and is purposefully

implemented here to behave identically to those implementations.

• Various build management tools are implemented using scripting languages such as

Perl or Python and thus provide a natural embedded scripting language, similar to

GNU make’s integration of GNU Guile.

The remaining features are inventions new in GNU make:

• Use the ‘-v’ or ‘--version’ option to print version and copyright information.

• Use the ‘-h’ or ‘--help’ option to summarize the options to make.

• Simply-expanded variables. See Section 6.2 [The Two Flavors of Variables], page 60.

• Pass command line variable assignments automatically through the variable MAKE to

recursive make invocations. See Section 5.7 [Recursive Use of make], page 50.

• Use the ‘-C’ or ‘--directory’ command option to change directory. See Section 9.7

[Summary of Options], page 104.

• Make verbatim variable deﬁnitions with define. See Section 6.8 [Deﬁning Multi-Line

Variables], page 69.

1 2 ... 149 150 151 152 153 154 155 156 157 158 159 ... 211 212

Comentarios a estos manuales

Sin comentarios

Roland Ver. 4.5 Información técnica Pagina 154

Comentarios a estos manuales

Relacionado con productos y manuales para Impresión y escaneo Roland Ver. 4.5