NAME¶
pstotext - extract ASCII text from a PostScript or PDF file
SYNTAX¶
pstotext [option|pathname]...
where option includes:
- -cork
- -landscape
- -landscapeOther
- -portrait
- -
- -output file
- -gs command
- -debug
- -bboxes
DESCRIPTION¶
pstotext reads one or more PostScript or PDF files, and writes to
standard output a representation of the plain text that would be displayed if
the PostScript file were printed. As is described in the DETAILS section
below, this representation is only an approximation. Nevertheless, it is often
useful for information retrieval (e.g., running
grep(1) or building a
full-text index) or to recover the text from a PostScript file whose source
you have lost.
pstotext calls Ghostscript, and requires Aladdin Ghostscript version 3.51
or newer. Ghostscript must be invokable on the current search path as gs.
Alternatively, you can use the -gs option to specify the command (pathname and
options) to run Ghostscript. For example, on Windows you might use -gs
"c:\gs\gswin32c.exe -Ic:\gs;c:\gs\fonts".
pstotext reads and processes its command line from left to right,
ignoring the case of options. When it encounters a pathname, it opens the file
and expects to find a PostScript job or PDF document to process. The option -
means to read and process a PostScript job from standard input. If no - or
pathname arguments are encountered,
pstotext reads a PostScript job
from standard input. (PDF documents require random access, hence cannot be
read from standard input.) You can use the -output option to specify an output
file (remember to invoke it
before the input file); otherwise
pstotext writes to standard output.
The option -cork is only relevant for PostScript files produced by dvips from
TeX or LaTeX documents; it tells
pstotext to use the Cork encoding
(known as T1 in LaTeX) rather than the old TeX text encoding (known as OT1 in
LaTeX). Unfortunately files produced by dvips don't distinguish which font
encodings were used.
The options -landscape and -landscapeOther should be used for documents that
must be rotated 90 degrees clockwise or counterclockwise, respectively, in
order to be readable.
The options -debug and -bboxes are mostly of use for the maintainers of
pstotext. -debug shows Ghostscript output and error messages. -bboxes
outputs one word per line with bounding box information.
DETAILS¶
pstotext does its work by telling Ghostscript to load a PostScript
library that causes it to write to its standard output information about each
string rendered by a PostScript job or PDF document. This information includes
the characters of the string, and enough additional information to approximate
the string's bounding rectangle.
pstotext post-processes this
information and outputs a sequence of words delimited by space, newline, and
formfeed.
pstotext outputs words in the same sequence as they are rendered by the
document. This usually, but not always, follows the order that a human would
read the words on a page. Within this sequence, words are separated by either
space or newline depending on whether or not they fall on the same line. Each
page is terminated with a formfeed. If you use the incorrect option from the
set {-portrait, -landscape, -landscapeOther},
pstotext is likely to
substitute newline for space.
A PostScript job or PDF document often renders one word as several strings in
order to get correct spacing between particular pairs of characters.
pstotext does its best to assemble these strings back into words, using
a simple heuristic: strings separated by a distance of less than 0.3 times the
minimum of the average character widths in the two strings are considered to
be part of the same word. Note that this typically causes leading and trailing
punctuation characters to be included with a word.
The PostScript language provides a flexible encoding scheme by which character
codes in strings select specific characters (symbols), so a PostScript job is
free to use any character code. On the other hand,
pstotext always
translates to the ISO 8859-1 (Latin-1) character code, which is an extension
to ASCII covering most of the Western European languages. When a character
isn't present in ISO 8859-1,
pstotext uses a sequence of characters,
e.g., "---" for em dash or "A\226" for Abreve.
pstotext can be fooled by a font whose Encoding vector doesn't follow
Adobe's conventions, but it contains heuristics allowing it to handle a wide
variety of misbehaving fonts.
(
pstotext no longer translates hyphen (\255) to minus (\055).)
AUTHOR¶
Andrew Birrell (PostScript libraries), Paul McJones (application), Russell Lang
(Windows and OS/2 adaptation), and Hunter Goatley (VMS adaptation).
SEE ALSO¶
pstotext incorporates technology originally developed for the Virtual
Paper project at SRC; see
http://www.research.digital.com/SRC/virtualpaper/.
As mentioned above,
pstotext invokes Ghostscript. See
gs(1) or
http://www.cs.wisc.edu/~ghost/.
COPYRIGHT¶
Copyright 1995-8 Digital Equipment Corporation.
Distributed only by permission.
See file /usr/share/doc/pstotext/copyright for details.
Last modified on Sat Feb 5 21:00:00 AEST 2000 by rjl
modified on Fri Jun 5 14:02:37 PDT 1998 by mcjones
modified on Wed Jun 7 17:47:56 PDT 1995 by birrell
This file was generated automatically by mtex software; see the mtex home page
at
http://www.research.digital.com/SRC/mtex/.