Re: Why I can't use `info' in emacs?

["Robert Thorpe" <rthorpe@realworldtech.com>]

Hadron Quark wrote:
> "Robert Thorpe" <rthorpe@realworldtech.com> writes:
>
> > It's not documented by Emacs, it's documented in the Info docs that
> > come with GLibc.
>
> I installed the glibc info package on my ubuntu system. restarted
> emacs. Here are some outputs from the info pages for glibc and the man
> pages for printf:
>
> (a) man page using manual-entry(current-word):
>
> ,----
> | PRINTF(3)                                      Linux Programmer's Manual                                     <snip>
> Surely the man pages are superior in this instance for a programmer?

It depends.  The GLibc manual is odd in that it's maintained in both
TexInfo format and Man format.  The TexInfo manual is used to generate
the HTML manual.  Sometimes the Man is better than the info, often it's
the other way around.

In this case Info returns much less documentation.  However, the info
manual is structured a little differently.  Hit "u" from the node where
you are and you'll see all the other stuff in the same section:-

* Formatted Output Basics     Some examples to get you started.
* Output Conversion Syntax    General syntax of conversion
specifications.
* Table of Output Conversions Summary of output conversions and what
they do.
* Integer Conversions         Details about formatting of integers.
* Floating-Point Conversions  Details about formatting of
floating-point numbers.
* Other Output Conversions    Details about formatting of strings,
characters, pointers, and the like.
* Formatted Output Functions  Descriptions of the actual functions.
* Dynamic Output              Functions that allocate memory for the
output.
* Variable Arguments Output   `vprintf' and friends.
* Parsing a Template String   What kinds of args does a given template
call for?
* Example of Parsing          Sample program using
`parse_printf_format'.

Hit 'u' again and you'll get more info on I/O functions.  The Info
manual explains all sorts of things like customizing printf that the
man-page doesn't cover.

The man-page is quite thorough in this case, but it is a little
confusing in one respect, It says "Linux Programmer's Manual".  I
have no idea why it says this, since printf is provided by Glibc.
Perhaps it dates from the time of Linux 2.1 when Linux had a different
C library.  More likely it's been written by someone in the Linux
project for continuity purposes, because people expect it there from
the days when Linux had it's own Libc.  If you are looking at the same
man page as me, then it documents many printf like functions, but not
quite all of them, not parse_printf_format for example.

Often the best manual depends on the function(!) The person who has
written the code tends to document it well in the manual they
themselves use.