printf(1) format additions

[Robert Elz <kre%munnari.OZ.AU@localhost>]

I have just added support for the F a and A formats to printf(1).

These are not required by POSIX, but nor are the e E f g or G formats,
which we did support. and supporting those 5 without the other 3 makes
allmost no sense (in the code they are essentially free, the only real cost
is a little more text in the man page).

Those are done.

But I also have support for the "data width modifiers" %ld %jx %Lf ...
(all of them I believe, as supported by printf(3), though not all are fully
supported., there is no %lc or %ls for example - those just generate
errors.)

These are also not required by POSIX.   They also mostly do nothing at
all (do not in any way change the output) - with a couple of exceptions.

Just like printf(3) %h truncates the argument to short (or unsigned short,
as appropriate) and %hh truncates to char (or unsigned char).  And %Lf
does (and all the other float formats with L do) use long double, rather than
double.

The point is just that it makes it easier to use printf(1) to test a proposed
format string to be used with printf(3), and make sure that the appearance
of the output is what you want, without needing to either recompile the
program all the time, or write a one-off special program that takes a format
string and data to print, and prints it (which is, really, what printf(1) is).

At least 'l' (as in %ld) is supported in some other printf(1) imlementations.

Any objections to adding support for these "data width" modifiers ?

kre