autogen.sh shell script rewrite

[tricantivu]

I have seen the pull request #174 by user @guijan, however, I disagree with the
code style and the argument against using echo.

I believe it is easier to validate the autogen.sh shell script command line
arguments and, albeit more readable by just expanding the first positional
parameter and ignoring the rest. Furthermore, the autogen.sh shell script
from #174 would consider an empty string as valid (e.g., ./autogen.sh '').

If the script were to become more complex, arguments can be parsed in other ways.

Regarding the use of the echo command, there should not be any significant
portability issue because all strings or arguments do not contain escape
sequences to be interpreted. When more formatting is required, echo can be
replaced to prevent errors because of the differences in their options. For
more information:

• https://man.openbsd.org/csh.1#echo
• https://man.openbsd.org/ksh.1#echo~2
• https://www.gnu.org/software/bash/manual/bash.html#index-echo
• https://git.kernel.org/pub/scm/utils/dash/dash.git/tree/src/bltin/printf.c#n458

While editing the autogen.sh shell script I noticed there was a
backslash near the end of a line with an rm command. Is there some line
length limit that I am not aware of?

[guijan]

The backslash is to avoid going over 80 columns in a line.

[tricantivu]

The backslash is to avoid going over 80 columns in a line.

Should I rebase my commits?

[guijan]

Should I rebase my commits?

Yes, break lines before they go over 80 columns.

[N-R-K]

Thanks for the PR, I've went with something simpler based on #174.