Commit Graph

5 Commits

Author SHA1 Message Date
Pawel Jakub Dawidek
4551abd040 Include stdio.h, so we can include printf.h in any order, as it needs FILE.
MFC after:	2 weeks
2011-03-06 17:45:37 +00:00
Poul-Henning Kamp
f3fede8ab9 Add nested include of <wchar.h> 2006-03-02 10:01:52 +00:00
Poul-Henning Kamp
8dcefe6112 Remove spurious "union arg" from printf.h
Make sure to always print something in the alternate time format.
2006-02-04 14:35:01 +00:00
Poul-Henning Kamp
6dbacee284 Make the %V{is} extension handle a NULL pointer like %s does: output "(null)"
Add %M{essage} extension which prints an errno value as the
corresponding string if possible or numerically otherwise.

It is not currently possible to do the syslog(3) like %m extension
because errno would need to get capatured on entry to the first
function in the printf family, so %M requires you to supply errno
as an argument.

Add %Q{uote} extension which will print a string in double quotes with
appropriate back-slash escapes (only) if necessary.
2006-01-25 12:45:24 +00:00
Poul-Henning Kamp
75067f4f70 Add an extensible version of our *printf(3) implementation to libc
on probationary terms:  it may go away again if it transpires it is
a bad idea.

This extensible printf version will only be used if either
    environment variable USE_XPRINTF is defined
or
    one of the extension functions are called.
or
    the global variable __use_xprintf is set greater than zero.

In all other cases our traditional printf implementation will
be used.

The extensible version is slower than the default printf, mostly
because less opportunity for combining I/O operation exists when
faced with extensions.  The default printf on the other hand
is a bad case of spaghetti code.

The extension API has a GLIBC compatible part and a FreeBSD version
of same.  The FreeBSD version exists because the GLIBC version may
run afoul of our FILE * locking in multithreaded programs and it
even further eliminate the opportunities for combining I/O operations.

Include three demo extensions which can be enabled if desired: time
(%T), hexdump (%H) and strvis (%V).

%T can format time_t (%T), struct timeval (%lT) and struct timespec (%llT)
   in one of two human readable duration formats:
	"%.3llT" -> "20349.245"
	"%#.3llT" -> "5h39m9.245"

%H will hexdump a sequence of bytes and takes a pointer and a length
   argument.  The width specifies number of bytes per line.
	"%4H" -> "65 72 20 65"
	"%+4H" -> "0000 65 72 20 65"
	"%#4H" -> "65 72 20 65  |er e|"
	"%+#4H" -> "0000 65 72 20 65  |er e|"

%V will dump a string in strvis format.
	"%V" -> "Hello\tWor\377ld"	(C-style)
	"%0V" -> "Hello\011Wor\377ld"	(octal)
	"%+V" -> "Hello%09Wor%FFld"	(http-style)

Tests, comments, bugreports etc are most welcome.
2005-12-16 18:56:39 +00:00