Re: suggested addition to 'date'

On Fri, Sep 01, 2006 at 01:06:06PM -0700, Julian Elischer wrote:
> Oliver Fromme wrote:
> 
> >Julian Elischer wrote:
> >> Oliver Fromme wrote:
> >> > John Baldwin wrote:
> >> > > Oliver Fromme wrote:
> >> > > > There's another possibility, which doesn't require a new
> >> > > > option letter at all.  You could add a new escape sequence
> >> > > > to the format string, e.g. "%*".  Whenever date(1) is
> >> > > > called with a format string containing that sequence, it
> >> > > > goes into filter mode and replaces the sequence with the
> >> > > > current line.  That would also enable you to be more
> >> > > > flexible with the placement of the timestamps.
> >> > > > For example:
> >> > > > 
> >> > > > $ printf 'foo\nbar\nbaz\n' | date +'%H:%M:%S %*'
> >> > > > 16:39:58 foo
> >> > > > 16:39:58 bar
> >> > > > 16:39:58 baz
> >> > > 
> >> > > I prefer this of all the suggestions so far.
> >> > 
> >> > It's not very difficult, so I created a patch which does
> >> > exactly that (includes an addition for the manpage, too).
> >> > I've submitted it as bin/102609:
> >> > 
> >> > http://www.freebsd.org/cgi/query-pr.cgi?pr=102609
> >> 
> >> A couple of comments:
> >> 
> >> you don't need to run strftime for each line if the time hasn't changed.
> >> (My original patch checks this)
> >
> >Good idea.  I'll update the patch.
> >
> >> What is the effective maximum line length for a single fgetln?
> >
> >It's unlimited.  fgetln() allocates sufficient amount of
> >memory dynamically, that's why I used it instead of fgets().
> >It avoids reinventing the wheel.
> > 
> >
> 
> NOTHING is unlimitted.
> what happens with a 3GB sequence of characters with no newlines?

$ man fgetln
[ ... ] 
     The fgetln() function may also fail and set errno for any of the errors
     specified for the routines fflush(3), malloc(3), read(2), stat(2), or
     realloc(3).
[...]

Looking at realloc, it sounds like you'll either get a 3GB string or
NULL and ENOMEM in errno.

-- 
Ted Faber
http://www.isi.edu/~faber           PGP: http://www.isi.edu/~faber/pubkeys.asc
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