1 .\" $Id: mandoc.1,v 1.176 2017/03/04 17:17:34 schwarze Exp $
3 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4 .\" Copyright (c) 2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
6 .\" Permission to use, copy, modify, and distribute this software for any
7 .\" purpose with or without fee is hereby granted, provided that the above
8 .\" copyright notice and this permission notice appear in all copies.
10 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 .Dd $Mdocdate: March 4 2017 $
23 .Nd format and display UNIX manuals
27 .Op Fl I Cm os Ns = Ns Ar name
39 manual pages for display.
47 text from stdin, implying
53 The options are as follows:
56 If the standard output is a terminal device and
60 to paginate the output, just like
64 Copy the formatted manual pages to the standard output without using
68 It can be specified to override
73 This overrides any earlier
79 Display only the SYNOPSIS lines.
82 .It Fl I Cm os Ns = Ns Ar name
83 Override the default operating system
93 Specify the input encoding.
101 If not specified, autodetection uses the first match in the following
105 If the first three bytes of the input file are the UTF-8 byte order
106 mark (BOM, 0xefbbbf), input is interpreted as
109 If the first or second line of the input file matches the
113 .D1 .\e" -*- Oo ...; Oc coding: Ar encoding ; No -*-
115 then input is interpreted according to
118 If the first non-ASCII byte in the file introduces a valid UTF-8
119 sequence, input is interpreted as
122 Otherwise, input is interpreted as
128 This overrides any earlier
136 Also reverts any earlier
141 .It Fl m Ns Ar format
145 for available formats.
149 Comma-separated output options.
154 for available formats.
158 Specify the minimum message
160 to be reported on the standard error output and to affect the exit status.
184 to exit after parsing a file that causes warnings or errors of at least
186 No formatted output will be produced from that file.
191 are requested, they can be joined with a comma, for example
192 .Fl W Cm error , Ns Cm stop .
194 Read input from zero or more files.
195 If unspecified, reads from stdin.
196 If multiple files are specified,
198 will halt with the first failed parse.
207 also supports the options
230 should only be used for legacy manuals.
234 which is also the default, determines encoding on-the-fly: if the first
241 parser is used; otherwise, the
246 files are specified with
248 each has its file-type determined this way.
249 If multiple files are
254 is specified, then this format is used exclusively.
258 utility accepts the following
260 arguments, which correspond to output modes:
261 .Bl -tag -width "-T markdown"
263 Produce 7-bit ASCII output.
267 Produce HTML5, CSS1, and MathML output.
271 Parse only: produce no output.
275 Encode output using the current locale.
290 .Sx Markdown Output .
296 Produce PostScript output.
298 .Sx PostScript Output .
300 Produce an indented parse tree.
302 .Sx Syntax tree output .
304 Encode output in the UTF\-8 multi-byte format.
308 This is a synonym for
312 If multiple input files are specified, these will be processed by the
313 corresponding filter in-order.
317 is rendered in standard 7-bit ASCII documented in
320 Font styles are applied by using back-spaced encoding such that an
324 .Sq _ Ns \e[bs] Ns c ,
327 is the back-space character number 8.
328 Emboldened characters are rendered as
329 .Sq c Ns \e[bs] Ns c .
331 The special characters documented in
333 are rendered best-effort in an ASCII equivalent.
335 Output width is limited to 78 visible columns unless literal input lines
340 arguments are accepted:
342 .It Cm indent Ns = Ns Ar indent
343 The left margin for normal text is set to
345 blank characters instead of the default of five for
349 Increasing this is not recommended; it may result in degraded formatting,
350 for example overfull lines or ugly line breaks.
351 .It Cm width Ns = Ns Ar width
352 The output width is set to
354 which will normalise to \(>=58.
359 conforms to HTML5 using optional self-closing tags.
360 Default styles use only CSS1.
361 Equations rendered from
367 file documents style-sheet classes available for customising output.
368 If a style-sheet is not specified with
371 defaults to simple output (via an embedded style-sheet)
372 readable in any graphical or text-based web
375 Special characters are rendered in decimal-encoded UTF\-8.
379 arguments are accepted:
382 Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
383 elements and only emit the subtree below the <body> element.
386 argument will be ignored.
387 This is useful when embedding manual content within existing documents.
388 .It Cm includes Ns = Ns Ar fmt
393 is used as a template for linked header files (usually via the
398 are replaced with the include filename.
399 The default is not to present a
401 .It Cm man Ns = Ns Ar fmt
405 .Ar ../html%S/%N.%S.html ,
406 is used as a template for linked manuals (usually via the
413 are replaced with the linked manual's name and section, respectively.
414 If no section is included, section 1 is assumed.
415 The default is not to
417 .It Cm style Ns = Ns Ar style.css
420 is used for an external style-sheet.
421 This must be a valid absolute or
425 Locale-depending output encoding is triggered with
429 This option is not available on all systems: systems without locale
430 support, or those whose internal representation is not natively UCS-4,
435 for font style specification and available command-line arguments.
437 Translate input format into
440 This is useful for distributing manual sources to legacy systems
447 is passed as input, it is translated into
449 If the input format is
451 the input is copied to the output, expanding any
455 The parser is also run, and as usual, the
459 are displayed before copying the input to the output.
466 .Lk http://daringfireball.net/projects/markdown/syntax.text\
467 "John Gruber's 2004 specification" .
469 Markdown is a very weak markup language, so all semantic markup is
470 lost, and even part of the presentational markup may be lost.
471 Do not use this as an intermediate step in converting to HTML;
481 input languages are not supported by
485 PDF-1.1 output may be generated by
488 .Sx PostScript Output
491 arguments and defaults.
492 .Ss PostScript Output
495 Level-2 pages may be generated by
497 Output pages default to letter sized and are rendered in the Times font
499 Margins are calculated as 1/9 the page length and width.
502 Special characters are rendered as in
507 arguments are accepted:
509 .It Cm paper Ns = Ns Ar name
519 You may also manually specify dimensions as
521 width by height in millimetres.
522 If an unknown value is encountered,
529 to force a UTF\-8 locale.
532 for details and options.
533 .Ss Syntax tree output
536 to show a human readable representation of the syntax tree.
537 It is useful for debugging the source code of manual pages.
538 The exact format is subject to change, so don't write parsers for it.
540 The first paragraph shows meta data found in the
545 line, or the fallbacks used.
547 In the tree dump, each output line shows one syntax tree node.
548 Child nodes are indented with respect to their parent node.
553 For macro nodes, the macro name; for text and
556 There is a special format for
560 Node type (text, elem, block, head, body, body-end, tail, tbl, eqn).
565 An opening parenthesis if the node is an opening delimiter.
567 An asterisk if the node starts a new input line.
569 The input line number (starting at one).
573 The input column number (starting at one).
575 A closing parenthesis if the node is a closing delimiter.
577 A full stop if the node ends a sentence.
579 BROKEN if the node is a block broken by another block.
581 NOSRC if the node is not in the input file,
582 but automatically generated from macros.
584 NOPRT if the node is not supposed to generate output
585 for any output format.
591 argument is accepted:
594 Skip validation and show the unvalidated syntax tree.
595 This can help to find out whether a given behaviour is caused by
596 the parser or by the validator.
597 Meta data is not available in this case.
600 .Bl -tag -width MANPAGER
602 Any non-empty value of the environment variable
604 will be used instead of the standard pagination program,
607 Specifies the pagination program to use when
610 If neither PAGER nor MANPAGER is defined,
618 utility exits with one of the following values, controlled by the message
624 .Bl -tag -width Ds -compact
626 No warnings or errors occurred, or those that did were ignored because
627 they were lower than the requested
630 At least one warning occurred, but no error, and
634 At least one parsing error occurred,
635 but no unsupported feature was encountered, and
641 At least one unsupported feature was encountered, and
648 Invalid command line arguments were specified.
649 No input files have been read.
651 An operating system error occurred, for example exhaustion
652 of memory, file descriptors, or process table entries.
655 to exit at once, possibly in the middle of parsing or formatting a file.
663 To page manuals to the terminal:
665 .Dl $ mandoc \-W all,stop mandoc.1 2\*(Gt&1 | less
666 .Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
668 To produce HTML manuals with
672 .Dl $ mandoc \-T html -O style=mandoc.css mdoc.7 \*(Gt mdoc.7.html
674 To check over a large set of manuals:
676 .Dl $ mandoc \-T lint \(gafind /usr/src -name \e*\e.[1-9]\(ga
678 To produce a series of PostScript manuals for A4 paper:
680 .Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
686 format, for use on systems lacking an
690 .Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
692 Messages displayed by
696 .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
698 Line and column numbers start at 1.
699 Both are omitted for messages referring to an input file as a whole.
700 Macro names and arguments are omitted where meaningless.
701 Fatal messages about invalid command line arguments
702 or operating system errors, for example when memory is exhausted,
709 Message levels have the following meanings:
710 .Bl -tag -width "warning"
712 An input file uses unsupported low-level
715 The output may be incomplete and/or misformatted,
716 so using GNU troff instead of
718 to process the file may be preferable.
720 An input file contains invalid syntax that cannot be safely interpreted.
721 By discarding part of the input or inserting missing tokens,
722 the parser is able to continue, and the error does not prevent
723 generation of formatted output, but typically, preparing that
724 output involves information loss, broken document structure
725 or unintended formatting, no matter whether
727 or GNU troff is used.
728 In many cases, the output of
730 and GNU troff is identical, but in some,
732 is more resilient than GNU troff with respect to malformed input.
734 Non-existent or unreadable input files are also reported on the
737 In that case, the parser cannot even be started and no output
738 is produced from those input files.
740 An input file uses obsolete, discouraged or non-portable syntax.
741 All the same, the meaning of the input is unambiguous and a correct
742 rendering can be produced.
743 Documents causing warnings may render poorly when using other
744 formatting tools instead of
753 levels except those about non-existent or unreadable input files
754 are hidden unless their level, or a lower level, is requested using a
759 .Ss Warnings related to the document prologue
761 .It Sy "missing manual title, using UNTITLED"
765 macro has no arguments, or there is no
767 macro before the first non-prologue macro.
768 .It Sy "missing manual title, using \(dq\(dq"
772 macro, or it has no arguments.
773 .It Sy "lower case character in document title"
775 The title is still used as given in the
780 .It Sy "missing manual section, using \(dq\(dq"
786 macro lacks the mandatory section argument.
787 .It Sy "unknown manual section"
789 The section number in a
791 line is invalid, but still used.
792 .It Sy "missing date, using today's date"
794 The document was parsed as
800 macro has no arguments or only empty arguments;
801 or the document was parsed as
807 macro has less than three arguments or its third argument is empty.
808 .It Sy "cannot parse date, using it verbatim"
814 macro does not follow the conventional format.
815 .It Sy "missing Os macro, using \(dq\(dq"
817 The default or current system is not shown in this case.
818 .It Sy "duplicate prologue macro"
820 One of the prologue macros occurs more than once.
821 The last instance overrides all previous ones.
822 .It Sy "late prologue macro"
828 macro occurs after some non-prologue macro, but still takes effect.
829 .It Sy "skipping late title macro"
833 macro appears after the first non-prologue macro.
834 Traditional formatters cannot handle this because
835 they write the page header before parsing the document body.
836 Even though this technical restriction does not apply to
838 traditional semantics is preserved.
839 The late macro is discarded including its arguments.
840 .It Sy "prologue macros out of order"
842 The prologue macros are not given in the conventional order
846 All three macros are used even when given in another order.
848 .Ss Warnings regarding document structure
850 .It Sy ".so is fragile, better use ln(1)"
852 Including files only works when the parser program runs with the correct
853 current working directory.
854 .It Sy "no document body"
856 The document body contains neither text nor macros.
857 An empty document is shown, consisting only of a header and a footer line.
858 .It Sy "content before first section header"
860 Some macros or text precede the first
865 The offending macros and text are parsed and added to the top level
866 of the syntax tree, outside any section block.
867 .It Sy "first section is not NAME"
869 The argument of the first
877 .It Sy "NAME section without Nm before Nd"
879 The NAME section does not contain any
881 child macro before the first
884 .It Sy "NAME section without description"
886 The NAME section lacks the mandatory
889 .It Sy "description not at the end of NAME"
891 The NAME section does contain an
893 child macro, but other content follows it.
894 .It Sy "bad NAME section content"
896 The NAME section contains plain text or macros other than
900 .It Sy "missing comma before name"
902 The NAME section contains an
904 macro that is neither the first one nor preceded by a comma.
905 .It Sy "missing description line, using \(dq\(dq"
909 macro lacks the required argument.
910 The title line of the manual will end after the dash.
911 .It Sy "sections out of conventional order"
913 A standard section occurs after another section it usually precedes.
914 All section titles are used as given,
915 and the order of sections is not changed.
916 .It Sy "duplicate section title"
918 The same standard section title occurs more than once.
919 .It Sy "unexpected section"
921 A standard section header occurs in a section of the manual
922 where it normally isn't useful.
923 .It Sy "unusual Xr order"
925 In the SEE ALSO section, an
927 macro with a lower section number follows one with a higher number,
930 macros referring to the same section are out of alphabetical order.
931 .It Sy "unusual Xr punctuation"
933 In the SEE ALSO section, punctuation between two
935 macros differs from a single comma, or there is trailing punctuation
939 .It Sy "AUTHORS section without An macro"
941 An AUTHORS sections contains no
943 macros, or only empty ones.
944 Probably, there are author names lacking markup.
946 .Ss "Warnings related to macros and nesting"
948 .It Sy "obsolete macro"
952 manual for replacements.
953 .It Sy "macro neither callable nor escaped"
955 The name of a macro that is not callable appears on a macro line.
956 It is printed verbatim.
957 If the intention is to call it, move it to its own input line;
958 otherwise, escape it by prepending
960 .It Sy "skipping paragraph macro"
963 documents, this happens
966 at the beginning and end of sections and subsections
968 right before non-compact lists and displays
970 at the end of items in non-column, non-compact lists
972 and for multiple consecutive paragraph macros.
976 documents, it happens
988 macros having neither head nor body arguments
999 .It Sy "moving paragraph macro out of list"
1003 list contains a trailing paragraph macro.
1004 The paragraph macro is moved after the end of the list.
1005 .It Sy "skipping no-space macro"
1007 An input line begins with an
1010 The macro is ignored.
1011 .It Sy "blocks badly nested"
1013 If two blocks intersect, one should completely contain the other.
1014 Otherwise, rendered output is likely to look strange in any output
1015 format, and rendering in SGML-based output formats is likely to be
1016 outright wrong because such languages do not support badly nested
1018 Typical examples of badly nested blocks are
1019 .Qq Ic \&Ao \&Bo \&Ac \&Bc
1021 .Qq Ic \&Ao \&Bq \&Ac .
1029 .It Sy "nested displays are not portable"
1036 display occurs nested inside another
1041 but fails with most other implementations.
1042 .It Sy "moving content out of list"
1046 list block contains text or macros before the first
1049 The offending children are moved before the beginning of the list.
1050 .It Sy "fill mode already enabled, skipping"
1054 request occurs even though the document is still in fill mode,
1055 or already switched back to fill mode.
1057 .It Sy "fill mode already disabled, skipping"
1061 request occurs even though the document already switched to no-fill mode
1062 and did not switch back to fill mode yet.
1064 .It Sy "line scope broken"
1066 While parsing the next-line scope of the previous macro,
1067 another macro is found that prematurely terminates the previous one.
1068 The previous, interrupted macro is deleted from the parse tree.
1070 .Ss "Warnings related to missing arguments"
1072 .It Sy "skipping empty request"
1074 The macro name is missing from a macro definition request,
1077 control statement or operation keyword lacks its required argument.
1078 .It Sy "conditional request controls empty scope"
1080 A conditional request is only useful if any of the following
1081 follows it on the same logical input line:
1086 keyword to open a multi-line scope.
1088 A request or macro or some text, resulting in a single-line scope.
1090 The immediate end of the logical line without any intervening whitespace,
1091 resulting in next-line scope.
1093 Here, a conditional request is followed by trailing whitespace only,
1094 and there is no other content on its logical input line.
1095 Note that it doesn't matter whether the logical input line is split
1096 across multiple physical input lines using
1098 line continuation characters.
1099 This is one of the rare cases
1100 where trailing whitespace is syntactically significant.
1101 The conditional request controls a scope containing whitespace only,
1102 so it is unlikely to have a significant effect,
1103 except that it may control a following
1106 .It Sy "skipping empty macro"
1108 The indicated macro has no arguments and hence no effect.
1109 .It Sy "empty block"
1120 block contains nothing in its body and will produce no output.
1121 .It Sy "empty argument, using 0n"
1123 The required width is missing after
1130 .It Sy "missing display type, using -ragged"
1134 macro is invoked without the required display type.
1135 .It Sy "list type is not the first argument"
1139 macro, at least one other argument precedes the type argument.
1142 utility copes with any argument order, but some other
1144 implementations do not.
1145 .It Sy "missing -width in -tag list, using 8n"
1154 .It Sy "missing utility name, using \(dq\(dq"
1158 macro is called without an argument before
1160 has first been called with an argument.
1161 .It Sy "missing function name, using \(dq\(dq"
1165 macro is called without an argument.
1166 No function name is printed.
1167 .It Sy "empty head in list item"
1179 macro lacks the required argument.
1180 The item head is left empty.
1181 .It Sy "empty list item"
1193 An empty list item is shown.
1194 .It Sy "missing font type, using \efR"
1198 macro has no argument.
1199 It switches to the default font.
1200 .It Sy "unknown font type, using \efR"
1204 argument is invalid.
1205 The default font is used instead.
1206 .It Sy "nothing follows prefix"
1210 macro has no argument, or only one argument and no macro follows
1211 on the same input line.
1212 This defeats its purpose; in particular, spacing is not suppressed
1213 before the text or macros following on the next input line.
1214 .It Sy "empty reference block"
1218 macro is immediately followed by an
1220 macro on the next input line.
1221 Such an empty block does not produce any output.
1222 .It Sy "missing section argument"
1226 macro lacks its second, section number argument.
1227 The first argument, i.e. the name, is printed, but without subsequent
1229 .It Sy "missing -std argument, adding it"
1235 macro lacks the required
1242 even when it is not specified, but other implementations may not.
1243 .It Sy "missing option string, using \(dq\(dq"
1247 macro is invoked without any argument.
1248 An empty pair of square brackets is shown.
1249 .It Sy "missing resource identifier, using \(dq\(dq"
1253 macro is invoked without any argument.
1254 An empty pair of angle brackets is shown.
1255 .It Sy "missing eqn box, using \(dq\(dq"
1257 A diacritic mark or a binary operator is found,
1258 but there is nothing to the left of it.
1259 An empty box is inserted.
1261 .Ss "Warnings related to bad macro arguments"
1263 .It Sy "unterminated quoted argument"
1265 Macro arguments can be enclosed in double quote characters
1266 such that space characters and macro names contained in the quoted
1267 argument need not be escaped.
1268 The closing quote of the last argument of a macro can be omitted.
1269 However, omitting it is not recommended because it makes the code
1271 .It Sy "duplicate argument"
1277 macro has more than one
1284 All but the last instances of these arguments are ignored.
1285 .It Sy "skipping duplicate argument"
1289 macro has more than one
1294 All but the first of these arguments are ignored.
1295 .It Sy "skipping duplicate display type"
1299 macro has more than one type argument; the first one is used.
1300 .It Sy "skipping duplicate list type"
1304 macro has more than one type argument; the first one is used.
1305 .It Sy "skipping -width argument"
1319 .It Sy "wrong number of cells"
1322 list, the number of tabs or
1324 macros is less than the number expected from the list header line
1325 or exceeds the expected number by more than one.
1326 Missing cells remain empty, and all cells exceeding the number of
1327 columns are joined into one single cell.
1328 .It Sy "unknown AT&T UNIX version"
1332 macro has an invalid argument.
1333 It is used verbatim, with
1336 .It Sy "comma in function argument"
1342 macro contains a comma; it should probably be split into two arguments.
1343 .It Sy "parenthesis in function name"
1345 The first argument of an
1349 macro contains an opening or closing parenthesis; that's probably wrong,
1350 parentheses are added automatically.
1351 .It Sy "invalid content in Rs block"
1355 block contains plain text or non-% macros.
1356 The bogus content is left in the syntax tree.
1357 Formatting may be poor.
1358 .It Sy "invalid Boolean argument"
1362 macro has an argument other than
1366 The invalid argument is moved out of the macro, which leaves the macro
1367 empty, causing it to toggle the spacing mode.
1368 .It Sy "unknown font, skipping request"
1376 layout modifier has an unknown
1379 .It Sy "odd number of characters in request"
1383 request contains an odd number of characters.
1384 The last character is mapped to the blank character.
1386 .Ss "Warnings related to plain text"
1388 .It Sy "blank line in fill mode, using .sp"
1390 The meaning of blank input lines is only well-defined in non-fill mode:
1391 In fill mode, line breaks of text input lines are not supposed to be
1393 However, for compatibility with groff, blank lines in fill mode
1397 .It Sy "tab in filled text"
1399 The meaning of tab characters is only well-defined in non-fill mode:
1400 In fill mode, whitespace is not supposed to be significant
1401 on text input lines.
1402 As an implementation dependent choice, tab characters on text lines
1403 are passed through to the formatters in any case.
1404 Given that the text before the tab character will be filled,
1405 it is hard to predict which tab stop position the tab will advance to.
1406 .It Sy "whitespace at end of input line"
1407 .Pq mdoc , man , roff
1408 Whitespace at the end of input lines is almost never semantically
1409 significant \(em but in the odd case where it might be, it is
1410 extremely confusing when reviewing and maintaining documents.
1411 .It Sy "new sentence, new line"
1413 A new sentence starts in the middle of a text line.
1414 Start it on a new input line to help formatters produce correct spacing.
1415 .It Sy "bad comment style"
1417 Comment lines start with a dot, a backslash, and a double-quote character.
1420 utility treats the line as a comment line even without the backslash,
1421 but leaving out the backslash might not be portable.
1422 .It Sy "invalid escape sequence"
1424 An escape sequence has an invalid opening argument delimiter, lacks the
1425 closing argument delimiter, or the argument has too few characters.
1426 If the argument is incomplete,
1430 expand to an empty string,
1436 to the length of the incomplete argument.
1437 All other invalid escape sequences are ignored.
1438 .It Sy "undefined string, using \(dq\(dq"
1440 If a string is used without being defined before,
1441 its value is implicitly set to the empty string.
1442 However, defining strings explicitly before use
1443 keeps the code more readable.
1445 .Ss "Warnings related to tables"
1447 .It Sy "tbl line starts with span"
1449 The first cell in a table layout line is a horizontal span
1451 Data provided for this cell is ignored, and nothing is printed in the cell.
1452 .It Sy "tbl column starts with span"
1454 The first line of a table layout specification
1455 requests a vertical span
1457 Data provided for this cell is ignored, and nothing is printed in the cell.
1458 .It Sy "skipping vertical bar in tbl layout"
1460 A table layout specification contains more than two consecutive vertical bars.
1461 A double bar is printed, all additional bars are discarded.
1463 .Ss "Errors related to tables"
1465 .It Sy "non-alphabetic character in tbl options"
1467 The table options line contains a character other than a letter,
1468 blank, or comma where the beginning of an option name is expected.
1469 The character is ignored.
1470 .It Sy "skipping unknown tbl option"
1472 The table options line contains a string of letters that does not
1473 match any known option name.
1474 The word is ignored.
1475 .It Sy "missing tbl option argument"
1477 A table option that requires an argument is not followed by an
1478 opening parenthesis, or the opening parenthesis is immediately
1479 followed by a closing parenthesis.
1480 The option is ignored.
1481 .It Sy "wrong tbl option argument size"
1483 A table option argument contains an invalid number of characters.
1484 Both the option and the argument are ignored.
1485 .It Sy "empty tbl layout"
1487 A table layout specification is completely empty,
1488 specifying zero lines and zero columns.
1489 As a fallback, a single left-justified column is used.
1490 .It Sy "invalid character in tbl layout"
1492 A table layout specification contains a character that can neither
1493 be interpreted as a layout key character nor as a layout modifier,
1494 or a modifier precedes the first key.
1495 The invalid character is discarded.
1496 .It Sy "unmatched parenthesis in tbl layout"
1498 A table layout specification contains an opening parenthesis,
1499 but no matching closing parenthesis.
1500 The rest of the input line, starting from the parenthesis, has no effect.
1501 .It Sy "tbl without any data cells"
1503 A table does not contain any data cells.
1504 It will probably produce no output.
1505 .It Sy "ignoring data in spanned tbl cell"
1507 A table cell is marked as a horizontal span
1511 in the table layout, but it contains data.
1512 The data is ignored.
1513 .It Sy "ignoring extra tbl data cells"
1515 A data line contains more cells than the corresponding layout line.
1516 The data in the extra cells is ignored.
1517 .It Sy "data block open at end of tbl"
1519 A data block is opened with
1521 but never closed with a matching
1523 The remaining data lines of the table are all put into one cell,
1524 and any remaining cells stay empty.
1526 .Ss "Errors related to roff, mdoc, and man code"
1528 .It Sy "input stack limit exceeded, infinite loop?"
1530 Explicit recursion limits are implemented for the following features,
1531 in order to prevent infinite loops:
1534 expansion of nested escape sequences
1535 including expansion of strings and number registers,
1537 expansion of nested user-defined macros,
1543 When a limit is hit, the output is incorrect, typically losing
1544 some content, but the parser can continue.
1545 .It Sy "skipping bad character"
1546 .Pq mdoc , man , roff
1547 The input file contains a byte that is not a printable
1550 The message mentions the character number.
1551 The offending byte is replaced with a question mark
1553 Consider editing the input file to replace the byte with an ASCII
1554 transliteration of the intended character.
1555 .It Sy "skipping unknown macro"
1556 .Pq mdoc , man , roff
1557 The first identifier on a request or macro line is neither recognized as a
1559 request, nor as a user-defined macro, nor, respectively, as an
1564 It may be mistyped or unsupported.
1565 The request or macro is discarded including its arguments.
1566 .It Sy "skipping insecure request"
1568 An input file attempted to run a shell command
1569 or to read or write an external file.
1570 Such attempts are denied for security reasons.
1571 .It Sy "skipping item outside list"
1575 macro occurs outside any
1580 delimiter occurs outside any pile.
1581 It is discarded including its arguments.
1582 .It Sy "skipping column outside column list"
1586 macro occurs outside any
1589 It is discarded including its arguments.
1590 .It Sy "skipping end of block that is not open"
1591 .Pq mdoc , man , eqn , tbl , roff
1592 Various syntax elements can only be used to explicitly close blocks
1593 that have previously been opened.
1596 block closing macro, a
1603 right delimiter or closing brace, or the end of an equation, table, or
1605 conditional request is encountered but no matching block is open.
1606 The offending request or macro is discarded.
1607 .It Sy "fewer RS blocks open, skipping"
1611 macro is invoked with an argument, but less than the specified number of
1617 .It Sy "inserting missing end of block"
1621 macros as well as tables require explicit closing by dedicated macros.
1622 A block that doesn't support bad nesting
1623 ends before all of its children are properly closed.
1624 The open child nodes are closed implicitly.
1625 .It Sy "appending missing end of block"
1626 .Pq mdoc , man , eqn , tbl , roff
1627 At the end of the document, an explicit
1635 block, an equation, table, or
1637 conditional or ignore block is still open.
1638 The open block is closed implicitly.
1639 .It Sy "escaped character not allowed in a name"
1641 Macro, string and register identifiers consist of printable,
1642 non-whitespace ASCII characters.
1643 Escape sequences and characters and strings expressed in terms of them
1644 cannot form part of a name.
1645 The first argument of an
1653 request, or any argument of an
1655 request, or the name of a request or user defined macro being called,
1656 is terminated by an escape sequence.
1662 the request has no effect at all.
1669 what was parsed up to this point is used as the arguments to the request,
1670 and the rest of the input line is discarded including the escape sequence.
1671 When parsing for a request or a user-defined macro name to be called,
1672 only the escape sequence is discarded.
1673 The characters preceding it are used as the request or macro name,
1674 the characters following it are used as the arguments to the request or macro.
1675 .It Sy "NOT IMPLEMENTED: Bd -file"
1677 For security reasons, the
1679 macro does not support the
1682 By requesting the inclusion of a sensitive file, a malicious document
1683 might otherwise trick a privileged user into inadvertently displaying
1684 the file on the screen, revealing the file content to bystanders.
1685 The argument is ignored including the file name following it.
1686 .It Sy "skipping display without arguments"
1690 block macro does not have any arguments.
1691 The block is discarded, and the block content is displayed in
1692 whatever mode was active before the block.
1693 .It Sy "missing list type, using -item"
1697 macro fails to specify the list type.
1698 .It Sy "missing manual name, using \(dq\(dq"
1702 or any call in the NAME section, lacks the required argument.
1703 .It Sy "uname(3) system call failed, using UNKNOWN"
1707 macro is called without arguments, and the
1712 can be compiled with
1714 .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
1716 .It Sy "unknown standard specifier"
1720 macro has an unknown argument and is discarded.
1721 .It Sy "skipping request without numeric argument"
1730 statement has a non-numeric or negative argument or no argument at all.
1731 The invalid request or statement is ignored.
1732 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
1734 For security reasons,
1738 file inclusion requests only with relative paths
1739 and only without ascending to any parent directory.
1740 By requesting the inclusion of a sensitive file, a malicious document
1741 might otherwise trick a privileged user into inadvertently displaying
1742 the file on the screen, revealing the file content to bystanders.
1744 only shows the path as it appears behind
1746 .It Sy ".so request failed"
1750 request requires reading an external file, but the file could not be
1753 only shows the path as it appears behind
1755 .It Sy "skipping all arguments"
1756 .Pq mdoc , man , eqn , roff
1772 macro in a list that don't support item heads, a
1791 block closing request is invoked with at least one argument.
1792 All arguments are ignored.
1793 .It Sy "skipping excess arguments"
1794 .Pq mdoc , man , roff
1795 A macro or request is invoked with too many arguments:
1796 .Bl -dash -offset 2n -width 2n -compact
1805 with more than one argument
1808 with another argument after
1814 with more than one argument or with a non-integer argument
1819 family with more than two arguments
1822 with more than three arguments
1825 with more than five arguments
1831 with invalid arguments
1833 The excess arguments are ignored.
1835 .Ss Unsupported features
1837 .It Sy "input too large"
1841 cannot handle input files larger than its arbitrary size limit
1842 of 2^31 bytes (2 Gigabytes).
1843 Since useful manuals are always small, this is not a problem in practice.
1844 Parsing is aborted as soon as the condition is detected.
1845 .It Sy "unsupported control character"
1847 An ASCII control character supported by other
1849 implementations but not by
1851 was found in an input file.
1852 It is replaced by a question mark.
1853 .It Sy "unsupported roff request"
1855 An input file contains a
1857 request supported by GNU troff or Heirloom troff but not by
1859 and it is likely that this will cause information loss
1860 or considerable misformatting.
1861 .It Sy "eqn delim option in tbl"
1863 The options line of a table defines equation delimiters.
1864 Any equation source code contained in the table will be printed unformatted.
1865 .It Sy "unsupported table layout modifier"
1867 A table layout specification contains an
1870 The modifier is discarded.
1871 .It Sy "ignoring macro in table"
1872 .Pq tbl , mdoc , man
1873 A table contains an invocation of an
1877 macro or of an undefined macro.
1878 The macro is ignored, and its arguments are handled
1879 as if they were a text line.
1893 utility first appeared in
1907 utility was written by
1908 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1909 and is maintained by
1910 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .