1 .\" $Id: mandoc.1,v 1.174 2017/02/10 15:45:28 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: February 10 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:
102 .Bl -tag -width iso-8859-1
104 if the first three bytes of the input file
105 are the UTF-8 byte order mark (BOM, 0xefbbbf)
107 if the first or second line of the input file matches the
111 .D1 .\e" -*- Oo ...; Oc coding: Ar encoding ; No -*-
113 if the first non-ASCII byte in the file introduces a valid UTF-8 sequence
120 This overrides any earlier
128 Also reverts any earlier
133 .It Fl m Ns Ar format
137 for available formats.
141 Comma-separated output options.
146 for available formats.
150 Specify the minimum message
152 to be reported on the standard error output and to affect the exit status.
176 to exit after parsing a file that causes warnings or errors of at least
178 No formatted output will be produced from that file.
183 are requested, they can be joined with a comma, for example
184 .Fl W Cm error , Ns Cm stop .
186 Read input from zero or more files.
187 If unspecified, reads from stdin.
188 If multiple files are specified,
190 will halt with the first failed parse.
199 also supports the options
222 should only be used for legacy manuals.
226 which is also the default, determines encoding on-the-fly: if the first
233 parser is used; otherwise, the
238 files are specified with
240 each has its file-type determined this way.
241 If multiple files are
246 is specified, then this format is used exclusively.
250 utility accepts the following
252 arguments, which correspond to output modes:
253 .Bl -tag -width "-T locale"
255 Produce 7-bit ASCII output.
259 Produce HTML5, CSS1, and MathML output.
263 Parse only: produce no output.
267 Encode output using the current locale.
282 Produce PostScript output.
284 .Sx PostScript Output .
286 Produce an indented parse tree.
288 .Sx Syntax tree output .
290 Encode output in the UTF\-8 multi-byte format.
294 This is a synonym for
298 If multiple input files are specified, these will be processed by the
299 corresponding filter in-order.
303 is rendered in standard 7-bit ASCII documented in
306 Font styles are applied by using back-spaced encoding such that an
310 .Sq _ Ns \e[bs] Ns c ,
313 is the back-space character number 8.
314 Emboldened characters are rendered as
315 .Sq c Ns \e[bs] Ns c .
317 The special characters documented in
319 are rendered best-effort in an ASCII equivalent.
321 Output width is limited to 78 visible columns unless literal input lines
326 arguments are accepted:
328 .It Cm indent Ns = Ns Ar indent
329 The left margin for normal text is set to
331 blank characters instead of the default of five for
335 Increasing this is not recommended; it may result in degraded formatting,
336 for example overfull lines or ugly line breaks.
337 .It Cm width Ns = Ns Ar width
338 The output width is set to
340 which will normalise to \(>=58.
345 conforms to HTML5 using optional self-closing tags.
346 Default styles use only CSS1.
347 Equations rendered from
353 file documents style-sheet classes available for customising output.
354 If a style-sheet is not specified with
357 defaults to simple output (via an embedded style-sheet)
358 readable in any graphical or text-based web
361 Special characters are rendered in decimal-encoded UTF\-8.
365 arguments are accepted:
368 Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
369 elements and only emit the subtree below the <body> element.
372 argument will be ignored.
373 This is useful when embedding manual content within existing documents.
374 .It Cm includes Ns = Ns Ar fmt
379 is used as a template for linked header files (usually via the
384 are replaced with the include filename.
385 The default is not to present a
387 .It Cm man Ns = Ns Ar fmt
391 .Ar ../html%S/%N.%S.html ,
392 is used as a template for linked manuals (usually via the
399 are replaced with the linked manual's name and section, respectively.
400 If no section is included, section 1 is assumed.
401 The default is not to
403 .It Cm style Ns = Ns Ar style.css
406 is used for an external style-sheet.
407 This must be a valid absolute or
411 Locale-depending output encoding is triggered with
415 This option is not available on all systems: systems without locale
416 support, or those whose internal representation is not natively UCS-4,
421 for font style specification and available command-line arguments.
423 Translate input format into
426 This is useful for distributing manual sources to legacy systems
433 is passed as input, it is translated into
435 If the input format is
437 the input is copied to the output, expanding any
441 The parser is also run, and as usual, the
445 are displayed before copying the input to the output.
447 PDF-1.1 output may be generated by
450 .Sx PostScript Output
453 arguments and defaults.
454 .Ss PostScript Output
457 Level-2 pages may be generated by
459 Output pages default to letter sized and are rendered in the Times font
461 Margins are calculated as 1/9 the page length and width.
464 Special characters are rendered as in
469 arguments are accepted:
471 .It Cm paper Ns = Ns Ar name
481 You may also manually specify dimensions as
483 width by height in millimetres.
484 If an unknown value is encountered,
491 to force a UTF\-8 locale.
494 for details and options.
495 .Ss Syntax tree output
498 to show a human readable representation of the syntax tree.
499 It is useful for debugging the source code of manual pages.
500 The exact format is subject to change, so don't write parsers for it.
502 The first paragraph shows meta data found in the
507 line, or the fallbacks used.
509 In the tree dump, each output line shows one syntax tree node.
510 Child nodes are indented with respect to their parent node.
515 For macro nodes, the macro name; for text and
518 There is a special format for
522 Node type (text, elem, block, head, body, body-end, tail, tbl, eqn).
527 An opening parenthesis if the node is an opening delimiter.
529 An asterisk if the node starts a new input line.
531 The input line number (starting at one).
535 The input column number (starting at one).
537 A closing parenthesis if the node is a closing delimiter.
539 A full stop if the node ends a sentence.
541 BROKEN if the node is a block broken by another block.
543 NOSRC if the node is not in the input file,
544 but automatically generated from macros.
546 NOPRT if the node is not supposed to generate output
547 for any output format.
553 argument is accepted:
556 Skip validation and show the unvalidated syntax tree.
557 This can help to find out whether a given behaviour is caused by
558 the parser or by the validator.
559 Meta data is not available in this case.
562 .Bl -tag -width MANPAGER
564 Any non-empty value of the environment variable
566 will be used instead of the standard pagination program,
569 Specifies the pagination program to use when
572 If neither PAGER nor MANPAGER is defined,
580 utility exits with one of the following values, controlled by the message
586 .Bl -tag -width Ds -compact
588 No warnings or errors occurred, or those that did were ignored because
589 they were lower than the requested
592 At least one warning occurred, but no error, and
596 At least one parsing error occurred,
597 but no unsupported feature was encountered, and
603 At least one unsupported feature was encountered, and
610 Invalid command line arguments were specified.
611 No input files have been read.
613 An operating system error occurred, for example exhaustion
614 of memory, file descriptors, or process table entries.
617 to exit at once, possibly in the middle of parsing or formatting a file.
625 To page manuals to the terminal:
627 .Dl $ mandoc \-W all,stop mandoc.1 2\*(Gt&1 | less
628 .Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
630 To produce HTML manuals with
634 .Dl $ mandoc \-T html -O style=mandoc.css mdoc.7 \*(Gt mdoc.7.html
636 To check over a large set of manuals:
638 .Dl $ mandoc \-T lint \(gafind /usr/src -name \e*\e.[1-9]\(ga
640 To produce a series of PostScript manuals for A4 paper:
642 .Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
648 format, for use on systems lacking an
652 .Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
654 Messages displayed by
658 .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
660 Line and column numbers start at 1.
661 Both are omitted for messages referring to an input file as a whole.
662 Macro names and arguments are omitted where meaningless.
663 Fatal messages about invalid command line arguments
664 or operating system errors, for example when memory is exhausted,
671 Message levels have the following meanings:
672 .Bl -tag -width "warning"
674 An input file uses unsupported low-level
677 The output may be incomplete and/or misformatted,
678 so using GNU troff instead of
680 to process the file may be preferable.
682 An input file contains invalid syntax that cannot be safely interpreted.
683 By discarding part of the input or inserting missing tokens,
684 the parser is able to continue, and the error does not prevent
685 generation of formatted output, but typically, preparing that
686 output involves information loss, broken document structure
687 or unintended formatting, no matter whether
689 or GNU troff is used.
690 In many cases, the output of
692 and GNU troff is identical, but in some,
694 is more resilient than GNU troff with respect to malformed input.
696 Non-existent or unreadable input files are also reported on the
699 In that case, the parser cannot even be started and no output
700 is produced from those input files.
702 An input file uses obsolete, discouraged or non-portable syntax.
703 All the same, the meaning of the input is unambiguous and a correct
704 rendering can be produced.
705 Documents causing warnings may render poorly when using other
706 formatting tools instead of
715 levels except those about non-existent or unreadable input files
716 are hidden unless their level, or a lower level, is requested using a
721 .Ss Warnings related to the document prologue
723 .It Sy "missing manual title, using UNTITLED"
727 macro has no arguments, or there is no
729 macro before the first non-prologue macro.
730 .It Sy "missing manual title, using \(dq\(dq"
734 macro, or it has no arguments.
735 .It Sy "lower case character in document title"
737 The title is still used as given in the
742 .It Sy "missing manual section, using \(dq\(dq"
748 macro lacks the mandatory section argument.
749 .It Sy "unknown manual section"
751 The section number in a
753 line is invalid, but still used.
754 .It Sy "missing date, using today's date"
756 The document was parsed as
762 macro has no arguments or only empty arguments;
763 or the document was parsed as
769 macro has less than three arguments or its third argument is empty.
770 .It Sy "cannot parse date, using it verbatim"
776 macro does not follow the conventional format.
777 .It Sy "missing Os macro, using \(dq\(dq"
779 The default or current system is not shown in this case.
780 .It Sy "duplicate prologue macro"
782 One of the prologue macros occurs more than once.
783 The last instance overrides all previous ones.
784 .It Sy "late prologue macro"
790 macro occurs after some non-prologue macro, but still takes effect.
791 .It Sy "skipping late title macro"
795 macro appears after the first non-prologue macro.
796 Traditional formatters cannot handle this because
797 they write the page header before parsing the document body.
798 Even though this technical restriction does not apply to
800 traditional semantics is preserved.
801 The late macro is discarded including its arguments.
802 .It Sy "prologue macros out of order"
804 The prologue macros are not given in the conventional order
808 All three macros are used even when given in another order.
810 .Ss Warnings regarding document structure
812 .It Sy ".so is fragile, better use ln(1)"
814 Including files only works when the parser program runs with the correct
815 current working directory.
816 .It Sy "no document body"
818 The document body contains neither text nor macros.
819 An empty document is shown, consisting only of a header and a footer line.
820 .It Sy "content before first section header"
822 Some macros or text precede the first
827 The offending macros and text are parsed and added to the top level
828 of the syntax tree, outside any section block.
829 .It Sy "first section is not NAME"
831 The argument of the first
839 .It Sy "NAME section without Nm before Nd"
841 The NAME section does not contain any
843 child macro before the first
846 .It Sy "NAME section without description"
848 The NAME section lacks the mandatory
851 .It Sy "description not at the end of NAME"
853 The NAME section does contain an
855 child macro, but other content follows it.
856 .It Sy "bad NAME section content"
858 The NAME section contains plain text or macros other than
862 .It Sy "missing comma before name"
864 The NAME section contains an
866 macro that is neither the first one nor preceded by a comma.
867 .It Sy "missing description line, using \(dq\(dq"
871 macro lacks the required argument.
872 The title line of the manual will end after the dash.
873 .It Sy "sections out of conventional order"
875 A standard section occurs after another section it usually precedes.
876 All section titles are used as given,
877 and the order of sections is not changed.
878 .It Sy "duplicate section title"
880 The same standard section title occurs more than once.
881 .It Sy "unexpected section"
883 A standard section header occurs in a section of the manual
884 where it normally isn't useful.
885 .It Sy "unusual Xr order"
887 In the SEE ALSO section, an
889 macro with a lower section number follows one with a higher number,
892 macros referring to the same section are out of alphabetical order.
893 .It Sy "unusual Xr punctuation"
895 In the SEE ALSO section, punctuation between two
897 macros differs from a single comma, or there is trailing punctuation
901 .It Sy "AUTHORS section without An macro"
903 An AUTHORS sections contains no
905 macros, or only empty ones.
906 Probably, there are author names lacking markup.
908 .Ss "Warnings related to macros and nesting"
910 .It Sy "obsolete macro"
914 manual for replacements.
915 .It Sy "macro neither callable nor escaped"
917 The name of a macro that is not callable appears on a macro line.
918 It is printed verbatim.
919 If the intention is to call it, move it to its own input line;
920 otherwise, escape it by prepending
922 .It Sy "skipping paragraph macro"
925 documents, this happens
928 at the beginning and end of sections and subsections
930 right before non-compact lists and displays
932 at the end of items in non-column, non-compact lists
934 and for multiple consecutive paragraph macros.
938 documents, it happens
950 macros having neither head nor body arguments
961 .It Sy "moving paragraph macro out of list"
965 list contains a trailing paragraph macro.
966 The paragraph macro is moved after the end of the list.
967 .It Sy "skipping no-space macro"
969 An input line begins with an
972 The macro is ignored.
973 .It Sy "blocks badly nested"
975 If two blocks intersect, one should completely contain the other.
976 Otherwise, rendered output is likely to look strange in any output
977 format, and rendering in SGML-based output formats is likely to be
978 outright wrong because such languages do not support badly nested
980 Typical examples of badly nested blocks are
981 .Qq Ic \&Ao \&Bo \&Ac \&Bc
983 .Qq Ic \&Ao \&Bq \&Ac .
991 .It Sy "nested displays are not portable"
998 display occurs nested inside another
1003 but fails with most other implementations.
1004 .It Sy "moving content out of list"
1008 list block contains text or macros before the first
1011 The offending children are moved before the beginning of the list.
1012 .It Sy "fill mode already enabled, skipping"
1016 request occurs even though the document is still in fill mode,
1017 or already switched back to fill mode.
1019 .It Sy "fill mode already disabled, skipping"
1023 request occurs even though the document already switched to no-fill mode
1024 and did not switch back to fill mode yet.
1026 .It Sy "line scope broken"
1028 While parsing the next-line scope of the previous macro,
1029 another macro is found that prematurely terminates the previous one.
1030 The previous, interrupted macro is deleted from the parse tree.
1032 .Ss "Warnings related to missing arguments"
1034 .It Sy "skipping empty request"
1036 The macro name is missing from a macro definition request,
1039 control statement or operation keyword lacks its required argument.
1040 .It Sy "conditional request controls empty scope"
1042 A conditional request is only useful if any of the following
1043 follows it on the same logical input line:
1048 keyword to open a multi-line scope.
1050 A request or macro or some text, resulting in a single-line scope.
1052 The immediate end of the logical line without any intervening whitespace,
1053 resulting in next-line scope.
1055 Here, a conditional request is followed by trailing whitespace only,
1056 and there is no other content on its logical input line.
1057 Note that it doesn't matter whether the logical input line is split
1058 across multiple physical input lines using
1060 line continuation characters.
1061 This is one of the rare cases
1062 where trailing whitespace is syntactically significant.
1063 The conditional request controls a scope containing whitespace only,
1064 so it is unlikely to have a significant effect,
1065 except that it may control a following
1068 .It Sy "skipping empty macro"
1070 The indicated macro has no arguments and hence no effect.
1071 .It Sy "empty block"
1082 block contains nothing in its body and will produce no output.
1083 .It Sy "empty argument, using 0n"
1085 The required width is missing after
1092 .It Sy "missing display type, using -ragged"
1096 macro is invoked without the required display type.
1097 .It Sy "list type is not the first argument"
1101 macro, at least one other argument precedes the type argument.
1104 utility copes with any argument order, but some other
1106 implementations do not.
1107 .It Sy "missing -width in -tag list, using 8n"
1116 .It Sy "missing utility name, using \(dq\(dq"
1120 macro is called without an argument before
1122 has first been called with an argument.
1123 .It Sy "missing function name, using \(dq\(dq"
1127 macro is called without an argument.
1128 No function name is printed.
1129 .It Sy "empty head in list item"
1141 macro lacks the required argument.
1142 The item head is left empty.
1143 .It Sy "empty list item"
1155 An empty list item is shown.
1156 .It Sy "missing font type, using \efR"
1160 macro has no argument.
1161 It switches to the default font.
1162 .It Sy "unknown font type, using \efR"
1166 argument is invalid.
1167 The default font is used instead.
1168 .It Sy "nothing follows prefix"
1172 macro has no argument, or only one argument and no macro follows
1173 on the same input line.
1174 This defeats its purpose; in particular, spacing is not suppressed
1175 before the text or macros following on the next input line.
1176 .It Sy "empty reference block"
1180 macro is immediately followed by an
1182 macro on the next input line.
1183 Such an empty block does not produce any output.
1184 .It Sy "missing section argument"
1188 macro lacks its second, section number argument.
1189 The first argument, i.e. the name, is printed, but without subsequent
1191 .It Sy "missing -std argument, adding it"
1197 macro lacks the required
1204 even when it is not specified, but other implementations may not.
1205 .It Sy "missing option string, using \(dq\(dq"
1209 macro is invoked without any argument.
1210 An empty pair of square brackets is shown.
1211 .It Sy "missing resource identifier, using \(dq\(dq"
1215 macro is invoked without any argument.
1216 An empty pair of angle brackets is shown.
1217 .It Sy "missing eqn box, using \(dq\(dq"
1219 A diacritic mark or a binary operator is found,
1220 but there is nothing to the left of it.
1221 An empty box is inserted.
1223 .Ss "Warnings related to bad macro arguments"
1225 .It Sy "unterminated quoted argument"
1227 Macro arguments can be enclosed in double quote characters
1228 such that space characters and macro names contained in the quoted
1229 argument need not be escaped.
1230 The closing quote of the last argument of a macro can be omitted.
1231 However, omitting it is not recommended because it makes the code
1233 .It Sy "duplicate argument"
1239 macro has more than one
1246 All but the last instances of these arguments are ignored.
1247 .It Sy "skipping duplicate argument"
1251 macro has more than one
1256 All but the first of these arguments are ignored.
1257 .It Sy "skipping duplicate display type"
1261 macro has more than one type argument; the first one is used.
1262 .It Sy "skipping duplicate list type"
1266 macro has more than one type argument; the first one is used.
1267 .It Sy "skipping -width argument"
1281 .It Sy "wrong number of cells"
1284 list, the number of tabs or
1286 macros is less than the number expected from the list header line
1287 or exceeds the expected number by more than one.
1288 Missing cells remain empty, and all cells exceeding the number of
1289 columns are joined into one single cell.
1290 .It Sy "unknown AT&T UNIX version"
1294 macro has an invalid argument.
1295 It is used verbatim, with
1298 .It Sy "comma in function argument"
1304 macro contains a comma; it should probably be split into two arguments.
1305 .It Sy "parenthesis in function name"
1307 The first argument of an
1311 macro contains an opening or closing parenthesis; that's probably wrong,
1312 parentheses are added automatically.
1313 .It Sy "invalid content in Rs block"
1317 block contains plain text or non-% macros.
1318 The bogus content is left in the syntax tree.
1319 Formatting may be poor.
1320 .It Sy "invalid Boolean argument"
1324 macro has an argument other than
1328 The invalid argument is moved out of the macro, which leaves the macro
1329 empty, causing it to toggle the spacing mode.
1330 .It Sy "unknown font, skipping request"
1338 layout modifier has an unknown
1341 .It Sy "odd number of characters in request"
1345 request contains an odd number of characters.
1346 The last character is mapped to the blank character.
1348 .Ss "Warnings related to plain text"
1350 .It Sy "blank line in fill mode, using .sp"
1352 The meaning of blank input lines is only well-defined in non-fill mode:
1353 In fill mode, line breaks of text input lines are not supposed to be
1355 However, for compatibility with groff, blank lines in fill mode
1359 .It Sy "tab in filled text"
1361 The meaning of tab characters is only well-defined in non-fill mode:
1362 In fill mode, whitespace is not supposed to be significant
1363 on text input lines.
1364 As an implementation dependent choice, tab characters on text lines
1365 are passed through to the formatters in any case.
1366 Given that the text before the tab character will be filled,
1367 it is hard to predict which tab stop position the tab will advance to.
1368 .It Sy "whitespace at end of input line"
1369 .Pq mdoc , man , roff
1370 Whitespace at the end of input lines is almost never semantically
1371 significant \(em but in the odd case where it might be, it is
1372 extremely confusing when reviewing and maintaining documents.
1373 .It Sy "new sentence, new line"
1375 A new sentence starts in the middle of a text line.
1376 Start it on a new input line to help formatters produce correct spacing.
1377 .It Sy "bad comment style"
1379 Comment lines start with a dot, a backslash, and a double-quote character.
1382 utility treats the line as a comment line even without the backslash,
1383 but leaving out the backslash might not be portable.
1384 .It Sy "invalid escape sequence"
1386 An escape sequence has an invalid opening argument delimiter, lacks the
1387 closing argument delimiter, or the argument has too few characters.
1388 If the argument is incomplete,
1392 expand to an empty string,
1398 to the length of the incomplete argument.
1399 All other invalid escape sequences are ignored.
1400 .It Sy "undefined string, using \(dq\(dq"
1402 If a string is used without being defined before,
1403 its value is implicitly set to the empty string.
1404 However, defining strings explicitly before use
1405 keeps the code more readable.
1407 .Ss "Warnings related to tables"
1409 .It Sy "tbl line starts with span"
1411 The first cell in a table layout line is a horizontal span
1413 Data provided for this cell is ignored, and nothing is printed in the cell.
1414 .It Sy "tbl column starts with span"
1416 The first line of a table layout specification
1417 requests a vertical span
1419 Data provided for this cell is ignored, and nothing is printed in the cell.
1420 .It Sy "skipping vertical bar in tbl layout"
1422 A table layout specification contains more than two consecutive vertical bars.
1423 A double bar is printed, all additional bars are discarded.
1425 .Ss "Errors related to tables"
1427 .It Sy "non-alphabetic character in tbl options"
1429 The table options line contains a character other than a letter,
1430 blank, or comma where the beginning of an option name is expected.
1431 The character is ignored.
1432 .It Sy "skipping unknown tbl option"
1434 The table options line contains a string of letters that does not
1435 match any known option name.
1436 The word is ignored.
1437 .It Sy "missing tbl option argument"
1439 A table option that requires an argument is not followed by an
1440 opening parenthesis, or the opening parenthesis is immediately
1441 followed by a closing parenthesis.
1442 The option is ignored.
1443 .It Sy "wrong tbl option argument size"
1445 A table option argument contains an invalid number of characters.
1446 Both the option and the argument are ignored.
1447 .It Sy "empty tbl layout"
1449 A table layout specification is completely empty,
1450 specifying zero lines and zero columns.
1451 As a fallback, a single left-justified column is used.
1452 .It Sy "invalid character in tbl layout"
1454 A table layout specification contains a character that can neither
1455 be interpreted as a layout key character nor as a layout modifier,
1456 or a modifier precedes the first key.
1457 The invalid character is discarded.
1458 .It Sy "unmatched parenthesis in tbl layout"
1460 A table layout specification contains an opening parenthesis,
1461 but no matching closing parenthesis.
1462 The rest of the input line, starting from the parenthesis, has no effect.
1463 .It Sy "tbl without any data cells"
1465 A table does not contain any data cells.
1466 It will probably produce no output.
1467 .It Sy "ignoring data in spanned tbl cell"
1469 A table cell is marked as a horizontal span
1473 in the table layout, but it contains data.
1474 The data is ignored.
1475 .It Sy "ignoring extra tbl data cells"
1477 A data line contains more cells than the corresponding layout line.
1478 The data in the extra cells is ignored.
1479 .It Sy "data block open at end of tbl"
1481 A data block is opened with
1483 but never closed with a matching
1485 The remaining data lines of the table are all put into one cell,
1486 and any remaining cells stay empty.
1488 .Ss "Errors related to roff, mdoc, and man code"
1490 .It Sy "input stack limit exceeded, infinite loop?"
1492 Explicit recursion limits are implemented for the following features,
1493 in order to prevent infinite loops:
1496 expansion of nested escape sequences
1497 including expansion of strings and number registers,
1499 expansion of nested user-defined macros,
1505 When a limit is hit, the output is incorrect, typically losing
1506 some content, but the parser can continue.
1507 .It Sy "skipping bad character"
1508 .Pq mdoc , man , roff
1509 The input file contains a byte that is not a printable
1512 The message mentions the character number.
1513 The offending byte is replaced with a question mark
1515 Consider editing the input file to replace the byte with an ASCII
1516 transliteration of the intended character.
1517 .It Sy "skipping unknown macro"
1518 .Pq mdoc , man , roff
1519 The first identifier on a request or macro line is neither recognized as a
1521 request, nor as a user-defined macro, nor, respectively, as an
1526 It may be mistyped or unsupported.
1527 The request or macro is discarded including its arguments.
1528 .It Sy "skipping insecure request"
1530 An input file attempted to run a shell command
1531 or to read or write an external file.
1532 Such attempts are denied for security reasons.
1533 .It Sy "skipping item outside list"
1537 macro occurs outside any
1542 delimiter occurs outside any pile.
1543 It is discarded including its arguments.
1544 .It Sy "skipping column outside column list"
1548 macro occurs outside any
1551 It is discarded including its arguments.
1552 .It Sy "skipping end of block that is not open"
1553 .Pq mdoc , man , eqn , tbl , roff
1554 Various syntax elements can only be used to explicitly close blocks
1555 that have previously been opened.
1558 block closing macro, a
1565 right delimiter or closing brace, or the end of an equation, table, or
1567 conditional request is encountered but no matching block is open.
1568 The offending request or macro is discarded.
1569 .It Sy "fewer RS blocks open, skipping"
1573 macro is invoked with an argument, but less than the specified number of
1579 .It Sy "inserting missing end of block"
1583 macros as well as tables require explicit closing by dedicated macros.
1584 A block that doesn't support bad nesting
1585 ends before all of its children are properly closed.
1586 The open child nodes are closed implicitly.
1587 .It Sy "appending missing end of block"
1588 .Pq mdoc , man , eqn , tbl , roff
1589 At the end of the document, an explicit
1597 block, an equation, table, or
1599 conditional or ignore block is still open.
1600 The open block is closed implicitly.
1601 .It Sy "escaped character not allowed in a name"
1603 Macro, string and register identifiers consist of printable,
1604 non-whitespace ASCII characters.
1605 Escape sequences and characters and strings expressed in terms of them
1606 cannot form part of a name.
1607 The first argument of an
1615 request, or any argument of an
1617 request, or the name of a request or user defined macro being called,
1618 is terminated by an escape sequence.
1624 the request has no effect at all.
1631 what was parsed up to this point is used as the arguments to the request,
1632 and the rest of the input line is discarded including the escape sequence.
1633 When parsing for a request or a user-defined macro name to be called,
1634 only the escape sequence is discarded.
1635 The characters preceding it are used as the request or macro name,
1636 the characters following it are used as the arguments to the request or macro.
1637 .It Sy "NOT IMPLEMENTED: Bd -file"
1639 For security reasons, the
1641 macro does not support the
1644 By requesting the inclusion of a sensitive file, a malicious document
1645 might otherwise trick a privileged user into inadvertently displaying
1646 the file on the screen, revealing the file content to bystanders.
1647 The argument is ignored including the file name following it.
1648 .It Sy "skipping display without arguments"
1652 block macro does not have any arguments.
1653 The block is discarded, and the block content is displayed in
1654 whatever mode was active before the block.
1655 .It Sy "missing list type, using -item"
1659 macro fails to specify the list type.
1660 .It Sy "missing manual name, using \(dq\(dq"
1664 or any call in the NAME section, lacks the required argument.
1665 .It Sy "uname(3) system call failed, using UNKNOWN"
1669 macro is called without arguments, and the
1674 can be compiled with
1676 .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
1678 .It Sy "unknown standard specifier"
1682 macro has an unknown argument and is discarded.
1683 .It Sy "skipping request without numeric argument"
1692 statement has a non-numeric or negative argument or no argument at all.
1693 The invalid request or statement is ignored.
1694 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
1696 For security reasons,
1700 file inclusion requests only with relative paths
1701 and only without ascending to any parent directory.
1702 By requesting the inclusion of a sensitive file, a malicious document
1703 might otherwise trick a privileged user into inadvertently displaying
1704 the file on the screen, revealing the file content to bystanders.
1706 only shows the path as it appears behind
1708 .It Sy ".so request failed"
1712 request requires reading an external file, but the file could not be
1715 only shows the path as it appears behind
1717 .It Sy "skipping all arguments"
1718 .Pq mdoc , man , eqn , roff
1734 macro in a list that don't support item heads, a
1753 block closing request is invoked with at least one argument.
1754 All arguments are ignored.
1755 .It Sy "skipping excess arguments"
1756 .Pq mdoc , man , roff
1757 A macro or request is invoked with too many arguments:
1758 .Bl -dash -offset 2n -width 2n -compact
1767 with more than one argument
1770 with another argument after
1776 with more than one argument or with a non-integer argument
1781 family with more than two arguments
1784 with more than three arguments
1787 with more than five arguments
1793 with invalid arguments
1795 The excess arguments are ignored.
1797 .Ss Unsupported features
1799 .It Sy "input too large"
1803 cannot handle input files larger than its arbitrary size limit
1804 of 2^31 bytes (2 Gigabytes).
1805 Since useful manuals are always small, this is not a problem in practice.
1806 Parsing is aborted as soon as the condition is detected.
1807 .It Sy "unsupported control character"
1809 An ASCII control character supported by other
1811 implementations but not by
1813 was found in an input file.
1814 It is replaced by a question mark.
1815 .It Sy "unsupported roff request"
1817 An input file contains a
1819 request supported by GNU troff or Heirloom troff but not by
1821 and it is likely that this will cause information loss
1822 or considerable misformatting.
1823 .It Sy "eqn delim option in tbl"
1825 The options line of a table defines equation delimiters.
1826 Any equation source code contained in the table will be printed unformatted.
1827 .It Sy "unsupported table layout modifier"
1829 A table layout specification contains an
1832 The modifier is discarded.
1833 .It Sy "ignoring macro in table"
1834 .Pq tbl , mdoc , man
1835 A table contains an invocation of an
1839 macro or of an undefined macro.
1840 The macro is ignored, and its arguments are handled
1841 as if they were a text line.
1855 utility first appeared in
1869 utility was written by
1870 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1871 and is maintained by
1872 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .