part of shnell – a source to source compiler enhancement tool
© Jens Gustedt, 2018
Evaluate the argument list as the names of POSIX’ getconf configuration
variables and substitue with the value
Usage:
Replace meta-variable NAMEx (${NAME0}, ${NAME1} …) by the values of POSIX’ getconf configuration variables VARIABLEx. A leading underscore in such a POSIX configuration variable can be omitted. E.g the POSIX variable _REGEX_VERSION can be refered to as REGEX_VERSION.
If NAMEx= is omitted NAMEx defaults to VARIABLEx.
Two POSIX variables are always caught from the environment, POSIX_VERSION and POSIX2_VERSION. Thus a portable method to ensure that a platform is POSIX is to add
On a POSIX platform this should expand to something as
On other platforms this should be
POSIX variables could be obtained with the C APIs sysconf and confstr. The first type of variable results in an integer value that is of type long. We add the L integer suffix where we detect an integer value. For variables that are not provided by the platform, the return value is -1.
The second type of variable results in a string. These should not be used with the ${NAMEx} notation but only with #${NAMEx}.
Example:
#pragma CMOD amend getconf FALLBACK_PATH=PATH INT_MAX
char fallback[] = #${FALLBACK_PATH};
long int_max[] = ${INT_MAX};This should be replaced by something similar to
Coding and configuration
The following code is needed to enable the sh-module framework.SRC="$_" . "${0%%/${0##*/}}/import.sh"Imports
The following sh-modules are imported: