2 .\" The above line should force the use of eqn as a preprocessor
6 This file is part of groff, the GNU roff type-setting system.
8 Copyright (C) 1989, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
10 Free Software Foundation, Inc.
11 rewritten from scrach 2001 by Bernd Warken <bwarken@mayn.de>
13 Permission is granted to copy, distribute and/or modify this document
14 under the terms of the GNU Free Documentation License, Version 1.3 or
15 any later version published by the Free Software Foundation; with the
16 Invariant Sections being this .ig-section and AUTHORS, with no
17 Front-Cover Texts, and with no Back-Cover Texts.
19 A copy of the Free Documentation License is included as a file called
20 FDL in the main directory of the groff source package.
23 .\" --------------------------------------------------------------------
25 .\" --------------------------------------------------------------------
27 .\" ----------------- Document configuration
29 .\" Number register to decide whether the commands `{' and `}' are used
30 .\" 0: disable (actual default); 1: enable
34 Unfortunately, old versions of groff used an illogical position change
35 after some D\~commands (Dp, DP, Dt). If the number register
36 @STUPID_DRAWING_POSITIONING is 1 (actual default) then change position
37 after these commands, otherwise the position is not changed.
39 .nr @STUPID_DRAWING_POSITIONING 1
41 .\" ----------------- Semantical definitions
44 .ds @backslash \[rs]\"
45 .ds @linebreak \fR\[la]line-break\[ra]\fP\"
47 .\" Begin of macro definitions
50 .RI ( \,\\$1\/ ,\ \,\\$2\/ )\\$3
53 .offset \fI\\$1\fP\d\s-3\\$2\s+3\u \fI\\$3\fP\d\s-3\\$4\s+3\u \\$5
55 .\" format: .command <name> "<arguments>" <punctuation>
57 \fB\\$1\fP\ \fI\,\\$2\/\fP\\$3
59 .\" format: .D-command <subcommand> "<arguments>"
61 \fBD\\$1\fP\ \fI\,\\$2\/\fP\|\*[@linebreak]
64 .\" We set these as troff micromotions rather than eqn because \d and \u
65 .\" can be lifted to XML subscript/superscript tags. Don't change
66 .\" these to a parameterized string, man2html won't handle that.
67 .ds hv1 \fIh\d\s-3\&1\s+3\u\~v\d\s-3\&1\s+3\u\fP
68 .ds hv2 \fIh\d\s-3\&2\s+3\u\~v\d\s-3\&2\s+3\u\fP
69 .ds hvn \fIh\d\s-3\&n\s+3\u\~v\d\s-3\&n\s+3\u\fP
72 \fBDa\fP\ \*[hv1] \*[hv2]\|\*[@linebreak]
74 .\" graphics command .D with a variable number of arguments
75 .\" format: .D-multiarg <subcommand>
77 \fBD\\$1\fP\ \*[hv1] \*[hv2] .\|.\|. \*[hvn]\|\*[@linebreak]
79 .\" format: .x-command <subname> "<arguments>"
81 \fBx\\$1\fP\ \fI\\$2\fP\|\*[@linebreak]
84 .RI "(" "\\$1" " control command)"
87 .\" End of macro definitions
90 .\" --------------------------------------------------------------------
92 .\" --------------------------------------------------------------------
94 .TH GROFF_OUT @MAN5EXT@ "@MDATE@" "Groff Version @VERSION@"
97 groff_out \- groff intermediate output format
100 .\" --------------------------------------------------------------------
102 .\" --------------------------------------------------------------------
104 This manual page describes the
105 .I intermediate output
108 text processing system
109 .BR groff (@MAN1EXT@).
111 This output is produced by a run of the GNU
112 .BR @g@troff (@MAN1EXT@)
115 It contains already all device-specific information, but it is not yet
116 fed into a device postprocessor program.
123 .BR groff (@MAN1EXT@)
124 is a wrapper program around
126 that automatically calls a
127 postprocessor, this output does not show up normally.
129 This is why it is called
137 program provides the option
139 to inhibit postprocessing, such that the produced
140 .I intermediate output
141 is sent to standard output just like calling
147 In this document, the term
149 describes what is output by the GNU
152 .I intermediate output
153 refers to the language that is accepted by the parser that prepares
154 this output for the postprocessors.
156 This parser is smarter on whitespace and implements obsolete elements
157 for compatibility, otherwise both formats are the same.
159 Both formats can be viewed directly with
160 .BR \%gxditview (@MAN1EXT@).
164 The main purpose of the
165 .I intermediate output
166 concept is to facilitate the development of postprocessors by
167 providing a common programming interface for all devices.
169 It has a language of its own that is completely different from the
170 .BR groff (@MAN7EXT@)
175 language is a high-level programming language for text processing, the
176 .I intermediate output
177 language is a kind of low-level assembler language by specifying all
178 positions on the page for writing and drawing.
185 versions are denoted as
189 .I intermediate output
192 is fairly readable, while
194 output was hard to understand because of strange habits that are
195 still supported, but not used any longer by
200 .\" --------------------------------------------------------------------
201 .SH "LANGUAGE CONCEPTS"
202 .\" --------------------------------------------------------------------
208 input is cracked down to the information on what has to be printed at
209 what position on the intended device.
211 So the language of the
212 .I intermediate output
213 format can be quite small.
215 Its only elements are commands with or without arguments.
217 In this document, the term \[lq]command\[rq] always refers to the
218 .I intermediate output
219 language, never to the
221 language used for document formatting.
223 There are commands for positioning and text writing, for drawing, and
224 for device controlling.
227 .\" --------------------------------------------------------------------
229 .\" --------------------------------------------------------------------
231 .I Classical troff output
232 had strange requirements on whitespace.
236 output parser, however, is smart about whitespace by making it
239 The whitespace characters, i.e., the
244 characters, always have a syntactical meaning.
246 They are never printable because spacing within the output is always
247 done by positioning commands.
255 characters is treated as a single
259 It separates commands and arguments, but is only required when there
260 would occur a clashing between the command code and the arguments
263 Most often, this happens when variable length command names,
264 arguments, argument lists, or command clusters meet.
266 Commands and arguments with a known, fixed length need not be
273 A line break is a syntactical element, too.
275 Every command argument can be followed by whitespace, a comment, or a
279 .I syntactical line break
280 is defined to consist of optional
282 that is optionally followed by a comment, and a newline character.
286 The normal commands, those for positioning and text, consist of a
287 single letter taking a fixed number of arguments.
289 For historical reasons, the parser allows to stack such commands on
290 the same line, but fortunately, in
291 .I groff intermediate
293 every command with at least one argument is followed by a line break,
294 thus providing excellent readability.
297 The other commands \[em] those for drawing and device controlling \[em]
298 have a more complicated structure; some recognize long command names,
299 and some take a variable number of arguments.
305 commands were designed to request a
306 .I syntactical line break
307 after their last argument.
311 has an argument that can stretch over several lines, all other
312 commands must have all of their arguments on the same line as the
313 command, i.e., the arguments may not be split by a line break.
316 Empty lines, i.e., lines containing only space and/or a comment, can
319 They are just ignored.
322 .\" --------------------------------------------------------------------
324 .\" --------------------------------------------------------------------
326 Some commands take integer arguments that are assumed to represent
327 values in a measurement unit, but the letter for the corresponding
329 is not written with the output command arguments; see
330 .BR groff (@MAN7EXT@)
333 for more on this topic.
335 Most commands assume the scale indicator\~\c
337 the basic unit of the device, some use\~\c
341 of the device, while others, such as the color commands expect plain
344 Note that these scale indicators are relative to the chosen device.
346 They are defined by the parameters specified in the device's
349 .BR groff_font (@MAN5EXT@).
353 Note that single characters can have the eighth bit set, as can the
354 names of fonts and special characters (this is, glyphs).
356 The names of glyphs and fonts can be of arbitrary length.
358 A glyph that is to be printed will always be in the current font.
362 A string argument is always terminated by the next whitespace
363 character (space, tab, or newline); an embedded
365 character is regarded as part of the argument, not as the beginning of
368 An integer argument is already terminated by the next non-digit
369 character, which then is regarded as the first character of the next
373 .\" --------------------------------------------------------------------
375 .\" --------------------------------------------------------------------
377 .I intermediate output
378 document consists of two parts, the
386 is to set the general device parameters using three exactly specified
391 is guaranteed to consist of the following three lines (in that order):
403 with the arguments set as outlined in the section
404 .BR "Device Control Commands" .
406 However, the parser for the
407 .I intermediate output
408 format is able to swallow additional whitespace and comments as well.
414 is the main section for processing the document data.
416 Syntactically, it is a sequence of any commands different from the
420 Processing is terminated as soon as the first
422 command is encountered; the last line of any
423 .I groff intermediate output
424 always contains such a command.
432 A new page is started by a
435 Positioning, writing, and drawing commands are always done within the
436 current page, so they cannot occur before the first
439 Absolute positioning (by the
443 is done relative to the current page, all other positioning
444 is done relative to the current location within this page.
447 .\" --------------------------------------------------------------------
448 .SH "COMMAND REFERENCE"
449 .\" --------------------------------------------------------------------
451 This section describes all
452 .I intermediate output
453 commands, the classical commands as well as the
458 .\" --------------------------------------------------------------------
459 .SS "Comment Command"
460 .\" --------------------------------------------------------------------
463 .BI # anything \[la]end-of-line\[ra]
466 Ignore any characters from the
468 character up to the next newline character.
471 This command is the only possibility for commenting in the
475 Each comment can be preceded by arbitrary
478 every command can be terminated by a comment.
481 .\" --------------------------------------------------------------------
482 .SS "Simple Commands"
483 .\" --------------------------------------------------------------------
485 The commands in this subsection have a command code consisting of a
486 single character, taking a fixed number of arguments.
488 Most of them are commands for positioning and text writing.
490 These commands are smart about whitespace.
494 can be inserted before, after, and between the command letter and its
497 All of these commands are stackable, i.e., they can be preceded by
498 other simple commands or followed by arbitrary other commands on the
503 is only necessary when two integer arguments would clash or if the
504 preceding argument ends with a string argument.
507 .if \n[@USE_ENV_STACK]=1 \{\
510 Open a new environment by copying the actual device configuration data
511 to the environment stack.
513 The current environment is setup by the device specification and
514 manipulated by the setting commands.
519 Close the actual environment (opened by a preceding
521 and restore the previous environment from the environment
522 stack as the actual device configuration data.
524 .\} \" endif @USE_ENV_STACK
528 .command C xxx \[la]white-space\[ra]
529 Print a glyph (special character) named
536 is necessary to allow glyph names of arbitrary length.
538 The glyph is printed at the current print position; the
539 glyph's size is read from the font file.
541 The print position is not changed.
546 Print glyph with single-letter name\~\c
548 at the current print position;
549 the glyph's size is read from the font file.
551 The print position is not changed.
556 Set font to font number\~\c
558 (a non-negative integer).
563 Move right to the absolute vertical position\~\c
565 (a non-negative integer in basic units\~\c
567 relative to left edge of current page.
574 (a non-negative integer) basic units\~\c
576 horizontally to the right.
579 allows negative values for
587 .command m "color-scheme \fR[\fPcomponent .\|.\|.\fR]\fP"
588 Set the color for text (glyphs), line drawing, and the outline of
589 graphic objects using different color schemes; the analoguous command
590 for the filling color of graphic objects is
593 The color components are specified as integer arguments between 0 and
596 The number of color components and their meaning vary for the
597 different color schemes.
599 These commands are generated by the
602 .BR \*[@backslash]m .
604 No position changing.
614 .command mc "cyan magenta yellow"
615 Set color using the CMY color scheme, having the 3\~color components
616 cyan, magenta, and yellow.
621 Set color to the default color value
622 (black in most cases).
624 No component arguments.
629 Set color to the shade of gray given by the argument, an integer
630 between 0 (black) and \n[@maxcolor] (white).
634 .command mk "cyan magenta yellow black"
635 Set color using the CMYK color scheme, having the 4\~color components
636 cyan, magenta, yellow, and black.
639 .command mr "red green blue"
640 Set color using the RGB color scheme, having the 3\~color components
641 red, green, and blue.
648 Print glyph with index\~\c
650 (an integer, normally non-negative) of the current font.
652 The print position is not changed.
658 is used, negative values are emitted also to indicate an unbreakable space
663 represents an unbreakable space which has a width of 193\|u.
672 Inform the device about a line break, but no positioning is done by
678 the integer arguments
682 informed about the space before and after the current line to
684 .I intermediate output
685 more human readable without performing any action.
689 they are just ignored, but they must be provided for compatibility
695 Begin a new page in the outprint.
697 The page number is set to\~\c
700 This page is completely independent of pages formerly processed even
701 if those have the same page number.
703 The vertical position on the outprint is automatically set to\~0.
705 All positioning, writing, and drawing is always done relative to a
708 must be issued before any of these commands.
731 .command t xyz\|.\|.\|. \[la]white-space\[ra]
733 .command t "xyz\|.\|.\|.\& dummy-arg" \[la]white-space\[ra]
734 Print a word, i.e., a sequence of glyphs with single-letter names
738 etc., terminated by a space character or a line break; an optional
739 second integer argument is ignored (this allows the formatter to
740 generate an even number of arguments).
742 The first glyph should be printed at the current position, the
743 current horizontal position should then be increased by the width of
744 the first glyph, and so on for each glyph.
746 The widths of the glyph are read from the font file, scaled for the
747 current point size, and rounded to a multiple of the horizontal
750 Special characters (glyphs with names longer than a single letter)
751 cannot be printed using this command; use the
753 command for those glyphs.
757 extension; it is only used for devices whose
762 .BR groff_font (@MAN5EXT@).
766 .command u "n xyz\|.\|.\|." \[la]white-space\[ra]
767 Print word with track kerning.
769 This is the same as the
771 command except that after printing each glyph, the current
772 horizontal position is increased by the sum of the width of that
780 extension; it is only used for devices whose
785 .BR groff_font (@MAN5EXT@).
790 Move down to the absolute vertical position\~\c
792 (a non-negative integer in basic units\~\c
794 relative to upper edge of current page.
805 is a non-negative integer).
808 allows negative values for
817 Informs about a paddable whitespace to increase readability.
819 The spacing itself must be performed explicitly by a move command.
822 .\" --------------------------------------------------------------------
823 .SS "Graphics Commands"
824 .\" --------------------------------------------------------------------
826 Each graphics or drawing command in the
827 .I intermediate output
828 starts with the letter\~\c
830 followed by one or two characters that specify a subcommand; this
831 is followed by a fixed or variable number of integer arguments that
832 are separated by a single space character.
837 may not be followed by another command on the same line (apart from a
848 output follows the classical spacing rules (no space between command
849 and subcommand, all arguments are preceded by a single space
850 character), but the parser allows optional space between the command
851 letters and makes the space before the first argument optional.
853 As usual, each space can be any sequence of tab and space characters.
857 Some graphics commands can take a variable number of arguments.
859 In this case, they are integers representing a size measured in basic
866 stand for horizontal distances where positive means right, negative
872 stand for vertical distances where positive means down, negative up.
874 All these distances are offsets relative to the current location.
878 Unless indicated otherwise, each graphics command directly corresponds
883 .BR groff (@MAN7EXT@).
889 \~commands are assumed to be device-specific.
891 Its arguments are parsed as strings; the whole information is then
892 sent to the postprocessor.
896 In the following command reference, the syntax element
897 .I \[la]line-break\[ra]
899 .I syntactical line break
900 as defined in section
906 Draw B-spline from current position to offset
907 .indexed_offset h 1 v 1 ,
909 .indexed_offset h 2 v 2
910 if given, etc., up to
911 .indexed_offset h n v n .
912 This command takes a variable number of argument pairs; the current
913 position is moved to the terminal point of the drawn curve.
918 Draw arc from current position to
919 .indexed_offset h 1 v 1 \|+\|\c
920 .indexed_offset h 2 v 2
922 .indexed_offset h 1 v 1 ;
923 then move the current position to the final point of the arc.
929 .D-command C "d dummy-arg"
930 Draw a solid circle using the current fill color with diameter\~\c
932 (integer in basic units\~\c
934 with leftmost point at the current position; then move the current
935 position to the rightmost point of the circle.
937 An optional second integer argument is ignored (this allows to the
938 formatter to generate an even number of arguments).
947 Draw circle line with diameter\~\c
949 (integer in basic units\~\c
951 with leftmost point at the current position; then move the current
952 position to the rightmost point of the circle.
957 Draw a solid ellipse in the current fill color with a horizontal
960 and a vertical diameter of\~\c
962 (both integers in basic units\~\c
964 with the leftmost point at the current position; then move to the
965 rightmost point of the ellipse.
974 Draw an outlined ellipse with a horizontal diameter of\~\c
976 and a vertical diameter of\~\c
978 (both integers in basic units\~\c
980 with the leftmost point at current position; then move to the
981 rightmost point of the ellipse.
985 .D-command F "color-scheme \fR[\fPcomponent .\|.\|.\fR]\fP"
986 Set fill color for solid drawing objects using different color
987 schemes; the analoguous command for setting the color of text, line
988 graphics, and the outline of graphic objects is
991 The color components are specified as integer arguments between 0 and
994 The number of color components and their meaning vary for the
995 different color schemes.
997 These commands are generated by the
1000 .BR \*[@backslash]D'F\ .\|.\|. '
1003 (with no other corresponding graphics commands).
1005 No position changing.
1015 .D-command Fc "cyan magenta yellow"
1016 Set fill color for solid drawing objects using the CMY color scheme,
1017 having the 3\~color components cyan, magenta, and yellow.
1022 Set fill color for solid drawing objects to the default fill color value
1023 (black in most cases).
1025 No component arguments.
1029 .D-command Fg "gray"
1030 Set fill color for solid drawing objects to the shade of gray given by
1031 the argument, an integer between 0 (black) and \n[@maxcolor] (white).
1035 .D-command Fk "cyan magenta yellow black"
1036 Set fill color for solid drawing objects using the CMYK color scheme,
1037 having the 4\~color components cyan, magenta, yellow, and black.
1040 .D-command Fr "red green blue"
1041 Set fill color for solid drawing objects using the RGB color scheme,
1042 having the 3\~color components red, green, and blue.
1051 must be an integer in the range -32767 to 32767.
1055 .RI 0\|\[<=]\| n \|\[<=]\|1000
1056 Set the color for filling solid drawing objects to a shade of gray,
1057 where 0 corresponds to solid white, 1000 (the default) to solid black,
1058 and values inbetween to intermediate shades of gray; this is
1059 obsoleted by command
1063 .IR n "\|<\|0 or " n \|>\|1000
1064 Set the filling color to the color that is currently being used for
1065 the text and the outline, see command
1067 For example, the command sequence
1072 mg 0 0 \n[@maxcolor]
1078 sets all colors to blue.
1081 No position changing.
1092 Draw line from current position to offset
1094 (integers in basic units\~\c
1096 then set current position to the end of the drawn line.
1101 Draw a polygon line from current position to offset
1102 .indexed_offset h 1 v 1 ,
1103 from there to offset
1104 .indexed_offset h 2 v 2 ,
1106 .indexed_offset h n v n ,
1107 and from there back to the starting position.
1109 .ie \n[@STUPID_DRAWING_POSITIONING]=1 \{\
1110 For historical reasons, the position is changed by adding the sum of
1111 all arguments with odd index to the actual horizontal position and the
1112 even ones to the vertical position.
1114 Although this doesn't make sense it is kept for compatibility.
1118 As the polygon is closed, the end of drawing is the starting point, so
1119 the position doesn't change.
1129 The same macro as the corresponding
1131 command with the same arguments, but draws a solid polygon in the
1132 current fill color rather than an outlined polygon.
1134 .ie \n[@STUPID_DRAWING_POSITIONING]=1 \{\
1135 The position is changed in the same way as with
1139 No position changing.
1148 Set the current line thickness to\~\c
1150 (an integer in basic units\~\c
1156 select the smallest available line thickness; if
1158 set the line thickness proportional to the point size (this is the
1159 default before the first
1161 command was specified).
1163 .ie \n[@STUPID_DRAWING_POSITIONING]=1 \{\
1164 For historical reasons, the horizontal position is changed by adding
1165 the argument to the actual horizontal position, while the vertical
1166 position is not changed.
1168 Although this doesn't make sense it is kept for compatibility.
1172 No position changing.
1179 .\" --------------------------------------------------------------------
1180 .SS "Device Control Commands"
1181 .\" --------------------------------------------------------------------
1183 Each device control command starts with the letter
1185 followed by a space character (optional or arbitrary space/\:tab in
1187 and a subcommand letter or word; each argument (if any) must be
1194 commands are terminated by a
1195 .IR "syntactical line break" ;
1196 no device control command can be followed by another command on the same
1197 line (except a comment).
1200 The subcommand is basically a single letter, but to increase
1201 readability, it can be written as a word, i.e., an arbitrary sequence
1202 of characters terminated by the next tab, space, or newline character.
1204 All characters of the subcommand word but the first are simply ignored.
1208 outputs the initialization command
1212 and the resolution command
1221 are accepted as well to mean the same commands.
1224 In the following, the syntax element
1225 .I \[la]line-break\[ra]
1227 .I syntactical line break
1228 as defined in section
1236 as the intended name for the current file in error reports.
1238 This is useful for remembering the original file name when
1240 uses an internal piping mechanism.
1242 The input file is not changed by this command.
1252 Mount font position\~\c
1254 (a non-negative integer) with font named\~\c
1258 .BR groff_font (@MAN5EXT@).
1264 Set character height to\~\c
1266 (a positive integer in scaled points\~\c
1270 used the unit points (\c
1272 instead; see section
1281 This is the third command of the
1290 The classical documentation reads
1291 .I pause device, can be
1296 .x-command r "n\ h\ v"
1302 is the minimal horizontal motion, and
1304 the minimal vertical motion possible with this device; all arguments
1305 are positive integers in basic units\~\c
1309 This is the second command of the
1318 degrees (an integer in basic units\~\c
1325 Terminates the processing of the current file; issued as the last
1327 .I intermediate @g@troff
1334 Generate trailer information, if any.
1338 this is actually just ignored.
1344 Set name of device to word
1346 a sequence of characters ended by the next whitespace character.
1348 The possible device names coincide with those from the groff
1352 This is the first command of the
1359 Configure underlining of spaces.
1363 is\~1, start underlining of spaces;
1366 is\~0, stop underlining of spaces.
1368 This is needed for the
1372 mode and is ignored otherwise.
1380 .x-command X anything
1384 uninterpreted to the device.
1386 If the line following this command starts with a
1388 character this line is interpreted as a continuation line in the
1393 is ignored, but a newline character is sent instead to the device, the
1394 rest of the line is sent uninterpreted.
1396 The same applies to all following lines until the first character of a
1401 This command is generated by the
1404 .BR \*[@backslash]X .
1406 The line-continuing feature is a
1411 .\" --------------------------------------------------------------------
1412 .SS "Obsolete Command"
1413 .\" --------------------------------------------------------------------
1417 output, emitting a single glyph was mostly done by a very
1418 strange command that combined a horizontal move and the printing of a
1421 It didn't have a command code, but is represented by a 3-character
1422 argument consisting of exactly 2\~digits and a character.
1428 (exactly two decimal digits) basic units\~\c
1430 then print glyph with single-letter name\~\c
1439 .I syntactical space
1440 around and within this command is allowed to be added.
1442 Only when a preceding command on the same line ends with an argument
1443 of variable length a separating space is obligatory.
1448 large clusters of these and other commands were used, mostly without
1449 spaces; this made such output almost unreadable.
1455 For modern high-resolution devices, this command does not make sense
1456 because the width of the glyphs can become much larger than two
1461 this is only used for the devices
1473 provide a better functionality.
1476 .\" --------------------------------------------------------------------
1477 .SH "POSTPROCESSING"
1478 .\" --------------------------------------------------------------------
1482 postprocessors are programs that have the task to translate the
1483 .I intermediate output
1484 into actions that are sent to a device.
1486 A device can be some piece of hardware such as a printer, or a software
1487 file format suitable for graphical or text processing.
1491 system provides powerful means that make the programming of such
1492 postprocessors an easy task.
1494 There is a library function that parses the
1495 .I intermediate output
1496 and sends the information obtained to the device via methods of a
1497 class with a common interface for each device.
1501 postprocessor must only redefine the methods of this class.
1503 For details, see the reference in section
1507 .\" --------------------------------------------------------------------
1509 .\" --------------------------------------------------------------------
1511 This section presents the
1512 .I intermediate output
1513 generated from the same input for three different devices.
1515 The input is the sentence
1519 on the command line.
1523 High-resolution device
1530 \fBshell>\fP echo "hell world" | groff -Z -T ps
1561 This output can be fed into the postprocessor
1562 .BR grops (@MAN1EXT@)
1563 to get its representation as a PostScript file.
1567 Low-resolution device
1573 This is similar to the high-resolution device except that the
1574 positioning is done at a minor scale.
1576 Some comments (lines starting with
1578 were added for clarification; they were not generated by the
1584 \fBshell>\fP "hell world" | groff -Z -T latin1
1595 .I "# begin a new page"
1603 .I "# initial positioning on the page"
1607 .I "# write text `hell'"
1610 .I "# inform about a space, and do it by a horizontal jump"
1613 .I "# write text `world'"
1616 .I "# announce line break, but do nothing because ..."
1619 .I "# ... the end of the document has been reached"
1630 This output can be fed into the postprocessor
1631 .BR grotty (@MAN1EXT@)
1632 to get a formatted text document.
1636 Classical style output
1641 As a computer monitor has a very low resolution compared to modern
1643 .I intermediate output
1644 for the X\~devices can use the jump-and-write command with its 2-digit
1650 \fBshell>\fP "hell world" | groff -Z -T X100
1666 .I "# write text with old-style jump-and-write command"
1668 ch07e07l03lw06w11o07r05l03dh7
1679 This output can be fed into the postprocessor
1682 .BR \%gxditview (@MAN1EXT@)
1683 for displaying in\~X.
1687 Due to the obsolete jump-and-write command, the text clusters in the
1688 classical output are almost unreadable.
1691 .\" --------------------------------------------------------------------
1693 .\" --------------------------------------------------------------------
1696 .I intermediate output
1699 was first documented in
1703 .I groff intermediate output
1704 format is compatible with this specification except for the following
1709 The classical quasi device independence is not yet implemented.
1713 The old hardware was very different from what we use today.
1717 devices are also fundamentally different from the ones in
1721 For example, the classical PostScript device was called
1723 and had a resolution of 720 units per inch,
1727 device has a resolution of 72000 units per inch.
1729 Maybe, by implementing some rescaling mechanism similar to the
1730 classical quasi device independence, these could be integrated into
1736 The B-spline command
1738 is correctly handled by the
1739 .I intermediate output
1740 parser, but the drawing routines aren't implemented in some of the
1741 postprocessor programs.
1745 The argument of the commands
1749 has the implicit unit scaled point\~\c
1758 This isn't an incompatibility, but a compatible extension, for both
1759 units coincide for all devices without a
1761 parameter, including all classical and the
1767 devices with a sizescale parameter either did not exist, had a
1768 different name, or seem to have had a different resolution.
1770 So conflicts with classical devices are very unlikely.
1773 .ie \n[@STUPID_DRAWING_POSITIONING]=1 \{\
1775 The position changing after the commands
1780 is illogical, but as old versions of groff used this feature it is
1781 kept for compatibility reasons.
1782 .\} \" @STUPID_DRAWING_POSITIONING
1785 Temporarily, there existed some confusion on the positioning after the
1791 This has been clarified by establishing the classical rule for all
1792 groff drawing commands:
1798 The position after a graphic object has been drawn is at its end;
1799 for circles and ellipses, the "end" is at the right side.
1805 From this, the positionings specified for the drawing commands above
1806 follow quite naturally.
1807 .\} \" @STUPID_DRAWING_POSITIONING
1810 The differences between
1815 .BR groff_diff (@MAN7EXT@).
1818 .\" --------------------------------------------------------------------
1820 .\" --------------------------------------------------------------------
1823 .BI @FONTDIR@/dev name /DESC
1824 Device description file for device
1828 .IB \[la]groff-source-dir\[ra] /src/libs/libdriver/input.cpp
1829 Defines the parser and postprocessor for the
1833 It is located relative to the top directory of the
1837 This parser is the definitive specification of the
1838 .I groff intermediate output
1842 .\" --------------------------------------------------------------------
1844 .\" --------------------------------------------------------------------
1847 .BR groff (@MAN7EXT@)
1848 refers to a manual page; here
1852 of the man-page documentation system.
1854 To read the example, look up section\~@MAN7EXT@ in your desktop help
1855 system or call from the shell prompt
1861 \fBshell>\fP man @MAN7EXT@ groff
1867 For more details, see
1872 .BR groff (@MAN1EXT@)
1875 and further readings on groff.
1879 .BR groff (@MAN7EXT@)
1882 language such as numerical units and escape sequences.
1886 .BR groff_font (@MAN5EXT@)
1887 for details on the device scaling parameters of the
1893 .BR @g@troff (@MAN1EXT@)
1894 generates the device-independent intermediate output.
1898 .BR roff (@MAN7EXT@)
1899 for historical aspects and the general structure of roff systems.
1903 .BR groff_diff (@MAN7EXT@)
1904 The differences between the intermediate output in groff and classical
1909 .BR gxditview (@MAN1EXT@)
1916 .BR \%grodvi (@MAN1EXT@),
1917 .BR \%grohtml (@MAN1EXT@),
1918 .BR \%grolbp (@MAN1EXT@),
1919 .BR \%grolj4 (@MAN1EXT@),
1920 .BR \%grops (@MAN1EXT@),
1921 .BR \%grotty (@MAN1EXT@)
1924 the groff postprocessor programs.
1929 For a treatment of all aspects of the groff system within a single
1934 It can be read within the integrated help systems, within
1936 or from the shell prompt by
1940 \fBshell>\fP info groff
1947 .I classical troff output language
1948 is described in two AT&T Bell Labs CSTR documents available on-line at
1949 .UR http://\:cm.bell-labs.com/\:cm/\:cs/\:cstr.html
1956 .I A Typesetter-independent TROFF
1959 is the original and most comprehensive documentation on the output
1961 .UR http://\:cm.bell-labs.com/\:cm/\:cs/\:cstr/\:97.ps.gz
1968 The 1992 revision of the
1969 .I Nroff/\:Troff User's Manual
1971 .I J.\& F.\& Ossanna
1974 isn't as comprehensive as
1976 regarding the output language; see
1977 .UR http://\:cm.bell-labs.com/\:cm/\:cs/\:cstr/\:54.ps.gz
1982 .\" --------------------------------------------------------------------
1984 .\" --------------------------------------------------------------------
1986 Copyright (C) 1989, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
1987 Free Software Foundation, Inc.
1991 This document is distributed under the terms of the FDL (GNU Free
1992 Documentation License) version 1.3 or later.
1994 You should have received a copy of the FDL with this package; it is also
1995 available on-line at the
1996 .UR http://\:www.gnu.org/\:copyleft/\:fdl.html
2002 This document is part of
2008 It is based on a former version \- published under the GPL \- that
2009 described only parts of the
2011 extensions of the output language.
2013 It was rewritten in 2002 by Bernd Warken and is
2019 .\" --------------------------------------------------------------------
2021 .\" --------------------------------------------------------------------
2023 .\" Local Variables:
projects / dragonfly.git / blob