From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/gnu_make/execution.html | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 devdocs/gnu_make/execution.html (limited to 'devdocs/gnu_make/execution.html') diff --git a/devdocs/gnu_make/execution.html b/devdocs/gnu_make/execution.html new file mode 100644 index 00000000..10f06b05 --- /dev/null +++ b/devdocs/gnu_make/execution.html @@ -0,0 +1,19 @@ +

Recipe Execution

When it is time to execute recipes to update a target, they are executed by invoking a new sub-shell for each line of the recipe, unless the .ONESHELL special target is in effect (see Using One Shell) (In practice, make may take shortcuts that do not affect the results.)

Please note: this implies that setting shell variables and invoking shell commands such as cd that set a context local to each process will not affect the following lines in the recipe.3 If you want to use cd to affect the next statement, put both statements in a single recipe line. Then make will invoke one shell to run the entire line, and the shell will execute the statements in sequence. For example: 

foo : bar/lose
+        cd $(<D) && gobble $(<F) > ../$@
+
+

Here we use the shell AND operator (&&) so that if the cd command fails, the script will fail without trying to invoke the gobble command in the wrong directory, which could cause problems (in this case it would certainly cause ../foo to be truncated, at least).

+ + + + + + + +
• One Shell + One shell for all lines in a recipe.
• Choosing the Shell + How make chooses the shell used to run recipes.
+

+ Copyright © 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022 Free Software Foundation, Inc.
Licensed under the GNU Free Documentation License.
+ https://www.gnu.org/software/make/manual/html_node/Execution.html +

+
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