The following environment variables shall affect the execution of
make:
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base
Definitions volume of POSIX.1‐2017, Section 8.2,
Internationalization Variables for the precedence of
internationalization variables used to determine the
values of locale categories.)
LC_ALL If set to a non-empty string value, override the values
of all the other internationalization variables.
LC_CTYPE Determine the locale for the interpretation of
sequences of bytes of text data as characters (for
example, single-byte as opposed to multi-byte
characters in arguments and input files).
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
MAKEFLAGS
This variable shall be interpreted as a character
string representing a series of option characters to be
used as the default options. The implementation shall
accept both of the following formats (but need not
accept them when intermixed):
* The characters are option letters without the
leading <hyphen-minus> characters or <blank>
separation used on a make utility command line.
* The characters are formatted in a manner similar to
a portion of the make utility command line: options
are preceded by <hyphen-minus> characters and
<blank>-separated as described in the Base
Definitions volume of POSIX.1‐2017, Section 12.2,
Utility Syntax Guidelines. The macro=value macro
definition operands can also be included. The
difference between the contents of MAKEFLAGS and
the make utility command line is that the contents
of the variable shall not be subjected to the word
expansions (see Section 2.6, Word Expansions)
associated with parsing the command line values.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
PROJECTDIR
Provide a directory to be used to search for SCCS files
not found in the current directory. In all of the
following cases, the search for SCCS files is made in
the directory SCCS in the identified directory. If the
value of PROJECTDIR begins with a <slash>, it shall be
considered an absolute pathname; otherwise, the value
of PROJECTDIR is treated as a user name and that user's
initial working directory shall be examined for a
subdirectory src or source. If such a directory is
found, it shall be used. Otherwise, the value is used
as a relative pathname.
If PROJECTDIR is not set or has a null value, the
search for SCCS files shall be made in the directory
SCCS in the current directory.
The setting of PROJECTDIR affects all files listed in
the remainder of this utility description for files
with a component named SCCS.
The value of the SHELL environment variable shall not be used as
a macro and shall not be modified by defining the SHELL macro in
a makefile or on the command line. All other environment
variables, including those with null values, shall be used as
macros, as defined in Macros.
