Re: how to achieve conversion to uppercase

[Paul Smith]

On Tue, 2013-09-10 at 10:09 +0100, Matej Kosik wrote:
> I am trying to figure out how to convert words to upper case.
> 
> Make itself does not seem to have dedicated function for this
> particular task, unless I am mistaken, so I guess I had to rely on
> bash.

> In bash, something like this:
>   var=foo; echo ${var^}
> works fine. I get:
>   Foo
> 
> However, if I try to embed this command with my makefile like this:
>   $(shell var=foo; echo $${var^})
> then I get:
>   /bin/sh: 1: Bad substitution

That's because make does not invoke bash.  Make invokes /bin/sh, which
is a POSIX compliant shell, so it doesn't understand many of the special
bash extensions (note that even if /bin/sh is actually bash, when
invoked as /bin/sh it disables many of bash's extended features).

It's best not to rely on this anyway, as it's not portable at all.

> I am not sure what exactly that string expands to by make before it is
> passed to bash so I am not sure which escape characters are missing
> (if that is the problem).

It is not the problem.  Try this from the command line:

    /bin/sh -c 'var=foo; echo ${var^}'

To write this portably you can use the tr(1) program:

    $(shell echo foo | tr a-z A-Z)

Or if you want to do it with make built-ins you can look at the GMSL:

  http://gmsl.sourceforge.net/