Re: printf produces no output for %f directive

[Eric Blake]

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According to Andreas Schwab on 10/19/2007 6:58 AM:
> Jim Meyering <address@hidden> writes:
> 
>> Could it be a bug in printf for failing, yet not setting the
>> stream-failure indicator that is checked by close_stdout's ferror?
> 
> A failure from printf does not necessarily mean an output failure.  It
> can also be ENOMEM or EILSEQ, which are unrelated to output.

Wow.  You're right.  Which means the return value of printf/fprintf must
always be checked in a secure program.  It looks like m4 has some bugs in
this area (admittedly corner case, since it is not on user-provided
strings with large padding values, so the likelihood of running out of
memory exactly during the printf is smaller)...

Would it be worth a xprintf and xfprintf gnulib wrapper that exits the
program immediately on non-output errors from the wrapped printf/fprintf?

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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