.TH GPHELP 1 "02 February June 2012"
.SH NAME
gphelp \- GP-PARI online help script
.SH SYNOPSIS
.BR gphelp
[-to_pod
.IR file ]
[-raw]
[-detex]
[-noskip]
[-utf8]
[-k]
[-ch
.IR c1 ]
[-cb
.IR c2 ]
[-cu
.IR c3 ]
[keyword [ @{1,2,3,4,5} ]]
[tutorial]
[refcard]...

.SH DESCRIPTION
Invokes the PARI-GP online help script. By default,
.I keyword
is understood as a section heading (a GP function name), and
.B gphelp
looks for it in Chapter 3 of PARI User's Manual. If it is found, the
corresponding section is copied to a temporary file in /tmp (or
.BR $GPTMPDIR ),
.B TeX
is run then the corresponding section is displayed in a separate window, using
.B xdvi
(or
.BR $GPXDVI ).


If more than one keyword is given on a single command line, the outputs are
concatenated. If
.I keyword
is omitted, open the whole manual
.IR users.dvi .
The keywords
.I tutorial
and
.I refcard
open the GP tutorial and reference card respectively.

GP defaults, help sections (1 to 11) as well as some keywords (readline,
bnf, ell, all operators...) are recognized and treated in a special way to
make sure they match a section heading. For instance
.B &&
is translated to
.I "Comparison and boolean operators"
which isn't that obvious to guess.
Make sure to enclose
.I keyword
between quotes if it contains dangerous characters (e.g spaces). For
instance, you need to type

.RS
gphelp -k "elliptic curves"
.RE

and not

.RS
gphelp -k elliptic curves
.RE

which would look for
"elliptic"
then for
"curves"
and output e.g.
.B ploth
among the relevant sections.

.SH FULL SEARCH: @ MARKERS

The pattern
.BR @ x
(where x is a chapter number between 1 and 5) at the end of
.I keyword
conducts the search in the corresponding chapter instead of the default
Chapter 3. If the number is omitted, search the whole manual. For instance
.RS
gphelp -k gerepile@4
.RE
will look for
.B gerepile
in Chapter 4 of users manual.
.RS
gphelp -k gerepile@
.RE
will search the whole manual. All chapters of the manual (usersch[1-5].tex)
are assumed to be in
.B $GPDOCDIR
.RI ( default value set by
Configure). You are allowed to gzip (or compress) them, this won't affect
the search.

.SH OPTIONS
The following command line options are available:
.TP
.BI -cb,\ -color_bold\  c2
color used for bold. See
.BR -color_help .

.TP
.BI -ch,\ -color_help\  c1
color (between 1 and 16) used for general printing. Only
significant in
.B detex
mode.

.TP
.BI -cu,\ -color_underline\  c3
color used for underline. See
.BR -color_help .

.TP
.BI \-detex
Use
.B detex
mode. The TeX file is converted to readable screen output that is directly
written to the terminal; don't use tex or xdvi.

.TP
.BI \-noskip
By default, the help text is continued when a new section is tagged with a
%GPHELPskip marker (on the same line). If this option is set, do not honor
markers: end the help text as soon as a new section is started.

.TP
.BI \-utf8
In
.B detex
mode, use UTF-8 encoding for characters, .e.g. use \('e (é) instead of 'e.

.TP
.BI \-k
Switch to
.B apropos
mode. Only write to standard output the list of section headings in manual
which contain
.IR keyword .

You can then choose an element in the list and use it as argument for
.B gphelp
(surround it by quotes if it includes spaces), possibly followed by a
trailing
.B @
marker (see above).

.TP
.BI \-raw
use internal format for output (using @x markers). For debugging only.

.TP
.BI \-to_pod\  file
try to convert
.I file
from TeX to POD format. Will only work on some subset of PARI User's Manual
(Chapter 3, reference card). This should be the only arguments on the
command line.

.SH ENVIRONMENT
.TP
COLUMNS
number of columns available on screen (for
.B detex
mode)

.TP
DISPLAY
where to launch the dvi previewer. If unset,
.B detex
mode is assumed automatically.

.TP
GPDOCDIR
directory where PARI help files are located. Default value set at Configure
time.

.TP
GPTEX
.RS
TeX typesetting program to use
.RE

.TP
GPTMPDIR
directory where temporary files are written

.TP
GPXDVI
.RS
dvi previewer to use. You may use this to specify options for vanilla xdvi,
for instance "xdvi -s 7" to select a shrink factor.
.RE

.SH FILES
.TP
.I gp
the gp calculator

.TP
.I gphelp
the gphelp script

.TP
.I users.dvi
PARI/GP User's Manual

.TP
.I tutorial.dvi
PARI/GP tutorial

.TP
.I refcard.dvi
GP reference card

.TP
.I refcard.ps
GP reference card, printer ready

.SH BUGS

The search algorithm is rather crude and the data searched rather
unstructured. Hence, searching outside of Chapter 3 may not yield useful
results, except in
.B apropos
mode (sections may be truncated too soon for instance).

Multiword search patterns have a tendency to fail due to various TeX
constructs in the source.

.SH AUTHORS
Originally written by Ilya Zakharevitch for the Math::Pari perl package.
Rewritten and expanded by Karim Belabas for the main PARI distribution.

.SH SEE ALSO
.IR gp (1),
.IR gzip (1),
.IR readline (1),
.IR tex (1),
.IR xdvi (1).

.SH COPYING

This program is  free  software;  you  can  redistribute  it
and/or  modify  it under the terms of the GNU General Public
License as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR  A  PARTICULAR  PURPOSE.  See the GNU General Public License for more
details.

You should have received a copy of the  GNU  General  Public
License  along  with this program; if not, write to the Free
Software Foundation,  Inc.,  675  Mass  Ave,  Cambridge,  MA
02139, USA.