groff: update vendor branch to v1.20.1

[dragonfly.git] / contrib / groff / contrib / eqn2graph / eqn2graph.man

.\" $Id: eqn2graph.man,v 1.6 2008/09/29 21:55:07 wl Exp $
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.TH EQN2GRAPH @MAN1EXT@ "@MDATE@" "Groff Version @VERSION@"
.IX eqn2graph
.SH NAME
eqn2graph \- convert an EQN equation into a cropped image
.
.
.SH SYNOPSIS
.B eqn2graph
[
.B \-unsafe
]
[
.BI \-format\  fmt
]
.
.
.SH DESCRIPTION
Reads an EQN equation (one line) as input; produces an image
file (by default in Portable Network Graphics format) suitable for the
Web as output.
.P
Your input EQN code should
.I not
have the \&.EQ/.EN preamble that
that normally precedes it within 
.BR groff (@MAN1EXT@) 
macros; nor do you need to have dollar-sign or other delimiters
around the equation.
.P
The output image will be clipped to the smallest possible bounding box
that contains all the black pixels.
Older versions of
.BR convert (1)
will produce a black-on-white graphic; newer ones may produce a
black-on-transparent graphic.
By specifying command-line options to be passed to 
.BR convert (1)
you can give it a border, force the background transparent, set the
image's pixel density, or perform other useful transformations.
.P
This program uses 
.BR @g@eqn (@MAN1EXT@),
.BR groff (@MAN1EXT@),
and the ImageMagick 
.BR convert (1)
program.
These programs must be installed on your system and accessible on your
$PATH for
.B eqn2graph
to work.
.
.
.SH OPTIONS
.TP
.B \-unsafe
Run 
.BR groff (@MAN1EXT@)
in the `unsafe' mode enabling the PIC macro
.B sh
to execute arbitrary commands.
The default is to forbid this.
.TP
.BI \-format\  fmt
Specify an output format; the default is PNG (Portable Network Graphics).
Any format that
.BR convert (1)
can emit is supported.
.PP
Command-line switches and arguments not listed above are passed to
.BR convert (1).
.
.
.SH FILES
.Tp \w'\fB@MACRODIR@/eqnrc'u+2n
.B @MACRODIR@/eqnrc
The 
.BR @g@eqn (@MAN1EXT@)
initialization file.
.
.
.SH ENVIRONMENT
.TP
.B GROFF_TMPDIR
The directory in which temporary files will be created.
If this is not set
.B eqn2graph
searches the environment variables
.BR \%TMPDIR ,
.BR TMP ,
and
.B TEMP
(in that order).
Otherwise, temporary files will be created in
.BR /tmp .
.
.
.SH BUGS
Due to changes in the behavior of ImageMagick
.BR convert (1)
that are both forward and backward-incompatible,
mismatches between your
.B eqn2graph
and 
.BR convert (1)
versions may produce zero-sized or untrimmed output images.
For this version of 
.B eqn2graph
you will need a version of
.BR convert (1)
that supports the
.B \-trim
option; older versions of 
.B eqn2graph
used
.BR \-crop\~0x0 ,
which no longer has trimming behavior.
.
.
.SH "SEE ALSO"
.BR pic2graph (@MAN1EXT@),
.BR grap2graph (@MAN1EXT@),
.BR @g@eqn (@MAN1EXT@),
.BR groff (@MAN1EXT@),
.BR gs (1),
.BR convert (1).
.
.
.SH AUTHOR
Eric S. Raymond <esr@thyrsus.com>.
.
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