That expands to `@PACKAGE_TARNAME@`, similar to the existing
PACKAGE_TARNAME variable.
To make it easier to use (and read) and to be more consistent with the
surrounding variables (NAME and VERSION).
Note that the original PACKAGE_TARNAME is still needed, as by default
(on autoconf v2.69) `docdir=@docdir@` in config.mk.in expands to the
following in config.mk:
docdir=${datarootdir}/doc/${PACKAGE_TARNAME}
Fix the following error and warnings:
$ shellcheck --version | grep ^version:
version: 0.8.0
$ shellcheck config.sh.in
In config.sh.in line 1:
# @configure_input@
^-- SC2148 (error): Tips depend on target shell and yours is unknown. Add a shebang or a 'shell' directive.
In config.sh.in line 3:
NAME=@PACKAGE_NAME@
^--^ SC2034 (warning): NAME appears unused. Verify use (or export if used externally).
In config.sh.in line 4:
VERSION=@PACKAGE_VERSION@
^-----^ SC2034 (warning): VERSION appears unused. Verify use (or export if used externally).
For more information:
https://www.shellcheck.net/wiki/SC2148 -- Tips depend on target shell and y...
https://www.shellcheck.net/wiki/SC2034 -- NAME appears unused. Verify use (...
Relates to #5140.
To note on the output files that they are generated and to clarify how
they are generated.
From the manual of GNU Autoconf (version 2.69):
> -- Variable: configure_input
> A comment saying that the file was generated automatically by
> 'configure' and giving the name of the input file. 'AC_OUTPUT'
> adds a comment line containing this variable to the top of every
> makefile it creates. For other files, you should reference this
> variable in a comment at the top of each input file. For
> example, an input shell script should begin like this:
>
> #!/bin/sh
> # @configure_input@
>
> The presence of that line also reminds people editing the file
> that it needs to be processed by 'configure' in order to be used.
Resulting output on config.mk:
# config.mk. Generated from config.mk.in by configure.
Relates to #5140.
