1 .\" $Id: mandoc.1,v 1.157 2015/03/27 21:40:04 schwarze Exp $
3 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4 .\" Copyright (c) 2012, 2014, 2015 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 27 2015 $
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
78 .It Fl I Cm os Ns = Ns Ar name
79 Override the default operating system
89 Display only the SYNOPSIS lines.
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 Encode output in the UTF\-8 multi-byte format.
292 This is a synonym for
296 If multiple input files are specified, these will be processed by the
297 corresponding filter in-order.
301 is rendered in standard 7-bit ASCII documented in
304 Font styles are applied by using back-spaced encoding such that an
308 .Sq _ Ns \e[bs] Ns c ,
311 is the back-space character number 8.
312 Emboldened characters are rendered as
313 .Sq c Ns \e[bs] Ns c .
315 The special characters documented in
317 are rendered best-effort in an ASCII equivalent.
319 Output width is limited to 78 visible columns unless literal input lines
324 arguments are accepted:
326 .It Cm indent Ns = Ns Ar indent
327 The left margin for normal text is set to
329 blank characters instead of the default of five for
333 Increasing this is not recommended; it may result in degraded formatting,
334 for example overfull lines or ugly line breaks.
335 .It Cm width Ns = Ns Ar width
336 The output width is set to
338 which will normalise to \(>=58.
343 conforms to HTML5 using optional self-closing tags.
344 Default styles use only CSS1.
345 Equations rendered from
350 .Pa example.style.css
351 file documents style-sheet classes available for customising output.
352 If a style-sheet is not specified with
355 defaults to simple output (via an embedded style-sheet)
356 readable in any graphical or text-based web
359 Special characters are rendered in decimal-encoded UTF\-8.
363 arguments are accepted:
366 Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
367 elements and only emit the subtree below the <body> element.
370 argument will be ignored.
371 This is useful when embedding manual content within existing documents.
372 .It Cm includes Ns = Ns Ar fmt
377 is used as a template for linked header files (usually via the
382 are replaced with the include filename.
383 The default is not to present a
385 .It Cm man Ns = Ns Ar fmt
389 .Ar ../html%S/%N.%S.html ,
390 is used as a template for linked manuals (usually via the
397 are replaced with the linked manual's name and section, respectively.
398 If no section is included, section 1 is assumed.
399 The default is not to
401 .It Cm style Ns = Ns Ar style.css
404 is used for an external style-sheet.
405 This must be a valid absolute or
409 Locale-depending output encoding is triggered with
413 This option is not available on all systems: systems without locale
414 support, or those whose internal representation is not natively UCS-4,
419 for font style specification and available command-line arguments.
421 Translate input format into
424 This is useful for distributing manual sources to legacy systems
431 is passed as input, it is translated into
433 If the input format is
435 the input is copied to the output, expanding any
439 The parser is also run, and as usual, the
443 are displayed before copying the input to the output.
445 PDF-1.1 output may be generated by
448 .Sx PostScript Output
451 arguments and defaults.
452 .Ss PostScript Output
455 Level-2 pages may be generated by
457 Output pages default to letter sized and are rendered in the Times font
459 Margins are calculated as 1/9 the page length and width.
462 Special characters are rendered as in
467 arguments are accepted:
469 .It Cm paper Ns = Ns Ar name
479 You may also manually specify dimensions as
481 width by height in millimetres.
482 If an unknown value is encountered,
489 to force a UTF\-8 locale.
492 for details and options.
494 .Bl -tag -width MANPAGER
496 Any non-empty value of the environment variable
498 will be used instead of the standard pagination program,
501 Specifies the pagination program to use when
504 If neither PAGER nor MANPAGER is defined,
505 .Pa /usr/bin/more Fl s
511 utility exits with one of the following values, controlled by the message
517 .Bl -tag -width Ds -compact
519 No warnings or errors occurred, or those that did were ignored because
520 they were lower than the requested
523 At least one warning occurred, but no error, and
527 At least one parsing error occurred,
528 but no unsupported feature was encountered, and
534 At least one unsupported feature was encountered, and
541 Invalid command line arguments were specified.
542 No input files have been read.
544 An operating system error occurred, for example exhaustion
545 of memory, file descriptors, or process table entries.
548 to exit at once, possibly in the middle of parsing or formatting a file.
556 To page manuals to the terminal:
558 .Dl $ mandoc \-W all,stop mandoc.1 2\*(Gt&1 | less
559 .Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
561 To produce HTML manuals with
565 .Dl $ mandoc \-T html -O style=style.css mdoc.7 \*(Gt mdoc.7.html
567 To check over a large set of manuals:
569 .Dl $ mandoc \-T lint `find /usr/src -name \e*\e.[1-9]`
571 To produce a series of PostScript manuals for A4 paper:
573 .Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
579 format, for use on systems lacking an
583 .Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
585 Messages displayed by
589 .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
591 Line and column numbers start at 1.
592 Both are omitted for messages referring to an input file as a whole.
593 Macro names and arguments are omitted where meaningless.
594 Fatal messages about invalid command line arguments
595 or operating system errors, for example when memory is exhausted,
602 Message levels have the following meanings:
603 .Bl -tag -width "warning"
605 An input file uses unsupported low-level
608 The output may be incomplete and/or misformatted,
609 so using GNU troff instead of
611 to process the file may be preferable.
613 An input file contains invalid syntax that cannot be safely interpreted.
614 By discarding part of the input or inserting missing tokens,
615 the parser is able to continue, and the error does not prevent
616 generation of formatted output, but typically, preparing that
617 output involves information loss, broken document structure
618 or unintended formatting, no matter whether
620 or GNU troff is used.
621 In many cases, the output of
623 and GNU troff is identical, but in some,
625 is more resilient than GNU troff with respect to malformed input.
627 Non-existent or unreadable input files are also reported on the
630 In that case, the parser cannot even be started and no output
631 is produced from those input files.
633 An input file uses obsolete, discouraged or non-portable syntax.
634 All the same, the meaning of the input is unambiguous and a correct
635 rendering can be produced.
636 Documents causing warnings may render poorly when using other
637 formatting tools instead of
646 levels except those about non-existent or unreadable input files
647 are hidden unless their level, or a lower level, is requested using a
652 .Ss Warnings related to the document prologue
654 .It Sy "missing manual title, using UNTITLED"
658 macro has no arguments, or there is no
660 macro before the first non-prologue macro.
661 .It Sy "missing manual title, using \(dq\(dq"
665 macro, or it has no arguments.
666 .It Sy "lower case character in document title"
668 The title is still used as given in the
673 .It Sy "missing manual section, using \(dq\(dq"
679 macro lacks the mandatory section argument.
680 .It Sy "unknown manual section"
682 The section number in a
684 line is invalid, but still used.
685 .It Sy "missing date, using today's date"
687 The document was parsed as
693 macro has no arguments or only empty arguments;
694 or the document was parsed as
700 macro has less than three arguments or its third argument is empty.
701 .It Sy "cannot parse date, using it verbatim"
707 macro does not follow the conventional format.
708 .It Sy "missing Os macro, using \(dq\(dq"
710 The default or current system is not shown in this case.
711 .It Sy "duplicate prologue macro"
713 One of the prologue macros occurs more than once.
714 The last instance overrides all previous ones.
715 .It Sy "late prologue macro"
721 macro occurs after some non-prologue macro, but still takes effect.
722 .It Sy "skipping late title macro"
726 macro appears after the first non-prologue macro.
727 Traditional formatters cannot handle this because
728 they write the page header before parsing the document body.
729 Even though this technical restriction does not apply to
731 traditional semantics is preserved.
732 The late macro is discarded including its arguments.
733 .It Sy "prologue macros out of order"
735 The prologue macros are not given in the conventional order
739 All three macros are used even when given in another order.
741 .Ss Warnings regarding document structure
743 .It Sy ".so is fragile, better use ln(1)"
745 Including files only works when the parser program runs with the correct
746 current working directory.
747 .It Sy "no document body"
749 The document body contains neither text nor macros.
750 An empty document is shown, consisting only of a header and a footer line.
751 .It Sy "content before first section header"
753 Some macros or text precede the first
758 The offending macros and text are parsed and added to the top level
759 of the syntax tree, outside any section block.
760 .It Sy "first section is not NAME"
762 The argument of the first
770 .It Sy "NAME section without name"
772 The NAME section does not contain any
775 .It Sy "NAME section without description"
777 The NAME section lacks the mandatory
780 .It Sy "description not at the end of NAME"
782 The NAME section does contain an
784 child macro, but other content follows it.
785 .It Sy "bad NAME section content"
787 The NAME section contains plain text or macros other than
791 .It Sy "missing description line, using \(dq\(dq"
795 macro lacks the required argument.
796 The title line of the manual will end after the dash.
797 .It Sy "sections out of conventional order"
799 A standard section occurs after another section it usually precedes.
800 All section titles are used as given,
801 and the order of sections is not changed.
802 .It Sy "duplicate section title"
804 The same standard section title occurs more than once.
805 .It Sy "unexpected section"
807 A standard section header occurs in a section of the manual
808 where it normally isn't useful.
809 .It Sy "unusual Xr order"
811 In the SEE ALSO section, an
813 macro with a lower section number follows one with a higher number,
816 macros referring to the same section are out of alphabetical order.
817 .It Sy "unusual Xr punctuation"
819 In the SEE ALSO section, punctuation between two
821 macros differs from a single comma, or there is trailing punctuation
825 .It Sy "AUTHORS section without An macro"
827 An AUTHORS sections contains no
829 macros, or only empty ones.
830 Probably, there are author names lacking markup.
832 .Ss "Warnings related to macros and nesting"
834 .It Sy "obsolete macro"
838 manual for replacements.
839 .It Sy "macro neither callable nor escaped"
841 The name of a macro that is not callable appears on a macro line.
842 It is printed verbatim.
843 If the intention is to call it, move it to its own input line;
844 otherwise, escape it by prepending
846 .It Sy "skipping paragraph macro"
849 documents, this happens
852 at the beginning and end of sections and subsections
854 right before non-compact lists and displays
856 at the end of items in non-column, non-compact lists
858 and for multiple consecutive paragraph macros.
862 documents, it happens
874 macros having neither head nor body arguments
885 .It Sy "moving paragraph macro out of list"
889 list contains a trailing paragraph macro.
890 The paragraph macro is moved after the end of the list.
891 .It Sy "skipping no-space macro"
893 An input line begins with an
896 The macro is ignored.
897 .It Sy "blocks badly nested"
899 If two blocks intersect, one should completely contain the other.
900 Otherwise, rendered output is likely to look strange in any output
901 format, and rendering in SGML-based output formats is likely to be
902 outright wrong because such languages do not support badly nested
904 Typical examples of badly nested blocks are
905 .Qq Ic \&Ao \&Bo \&Ac \&Bc
907 .Qq Ic \&Ao \&Bq \&Ac .
915 .It Sy "nested displays are not portable"
922 display occurs nested inside another
927 but fails with most other implementations.
928 .It Sy "moving content out of list"
932 list block contains text or macros before the first
935 The offending children are moved before the beginning of the list.
936 .It Sy ".Vt block has child macro"
940 macro supports plain text arguments only.
941 Formatting may be ugly and semantic searching
942 for the affected content might not work.
943 .It Sy "fill mode already enabled, skipping"
947 request occurs even though the document is still in fill mode,
948 or already switched back to fill mode.
950 .It Sy "fill mode already disabled, skipping"
954 request occurs even though the document already switched to no-fill mode
955 and did not switch back to fill mode yet.
957 .It Sy "line scope broken"
959 While parsing the next-line scope of the previous macro,
960 another macro is found that prematurely terminates the previous one.
961 The previous, interrupted macro is deleted from the parse tree.
963 .Ss "Warnings related to missing arguments"
965 .It Sy "skipping empty request"
967 The macro name is missing from a macro definition request,
970 control statement or operation keyword lacks its required argument.
971 .It Sy "conditional request controls empty scope"
973 A conditional request is only useful if any of the following
974 follows it on the same logical input line:
979 keyword to open a multi-line scope.
981 A request or macro or some text, resulting in a single-line scope.
983 The immediate end of the logical line without any intervening whitespace,
984 resulting in next-line scope.
986 Here, a conditional request is followed by trailing whitespace only,
987 and there is no other content on its logical input line.
988 Note that it doesn't matter whether the logical input line is split
989 across multiple physical input lines using
991 line continuation characters.
992 This is one of the rare cases
993 where trailing whitespace is syntactically significant.
994 The conditional request controls a scope containing whitespace only,
995 so it is unlikely to have a significant effect,
996 except that it may control a following
999 .It Sy "skipping empty macro"
1001 The indicated macro has no arguments and hence no effect.
1002 .It Sy "empty block"
1013 block contains nothing in its body and will produce no output.
1014 .It Sy "empty argument, using 0n"
1016 The required width is missing after
1023 .It Sy "missing display type, using -ragged"
1027 macro is invoked without the required display type.
1028 .It Sy "list type is not the first argument"
1032 macro, at least one other argument precedes the type argument.
1035 utility copes with any argument order, but some other
1037 implementations do not.
1038 .It Sy "missing -width in -tag list, using 8n"
1047 .It Sy "missing utility name, using \(dq\(dq"
1051 macro is called without an argument before
1053 has first been called with an argument.
1054 .It Sy "missing function name, using \(dq\(dq"
1058 macro is called without an argument.
1059 No function name is printed.
1060 .It Sy "empty head in list item"
1072 macro lacks the required argument.
1073 The item head is left empty.
1074 .It Sy "empty list item"
1086 An empty list item is shown.
1087 .It Sy "missing font type, using \efR"
1091 macro has no argument.
1092 It switches to the default font.
1093 .It Sy "unknown font type, using \efR"
1097 argument is invalid.
1098 The default font is used instead.
1099 .It Sy "nothing follows prefix"
1103 macro has no argument, or only one argument and no macro follows
1104 on the same input line.
1105 This defeats its purpose; in particular, spacing is not suppressed
1106 before the text or macros following on the next input line.
1107 .It Sy "empty reference block"
1111 macro is immediately followed by an
1113 macro on the next input line.
1114 Such an empty block does not produce any output.
1115 .It Sy "missing -std argument, adding it"
1121 macro lacks the required
1128 even when it is not specified, but other implementations may not.
1129 .It Sy "missing option string, using \(dq\(dq"
1133 macro is invoked without any argument.
1134 An empty pair of square brackets is shown.
1135 .It Sy "missing resource identifier, using \(dq\(dq"
1139 macro is invoked without any argument.
1140 An empty pair of angle brackets is shown.
1141 .It Sy "missing eqn box, using \(dq\(dq"
1143 A diacritic mark or a binary operator is found,
1144 but there is nothing to the left of it.
1145 An empty box is inserted.
1147 .Ss "Warnings related to bad macro arguments"
1149 .It Sy "unterminated quoted argument"
1151 Macro arguments can be enclosed in double quote characters
1152 such that space characters and macro names contained in the quoted
1153 argument need not be escaped.
1154 The closing quote of the last argument of a macro can be omitted.
1155 However, omitting it is not recommended because it makes the code
1157 .It Sy "duplicate argument"
1163 macro has more than one
1170 All but the last instances of these arguments are ignored.
1171 .It Sy "skipping duplicate argument"
1175 macro has more than one
1180 All but the first of these arguments are ignored.
1181 .It Sy "skipping duplicate display type"
1185 macro has more than one type argument; the first one is used.
1186 .It Sy "skipping duplicate list type"
1190 macro has more than one type argument; the first one is used.
1191 .It Sy "skipping -width argument"
1205 .It Sy "wrong number of cells"
1208 list, the number of tabs or
1210 macros is less than the number expected from the list header line
1211 or exceeds the expected number by more than one.
1212 Missing cells remain empty, and all cells exceeding the number of
1213 columns are joined into one single cell.
1214 .It Sy "unknown AT&T UNIX version"
1218 macro has an invalid argument.
1219 It is used verbatim, with
1222 .It Sy "comma in function argument"
1228 macro contains a comma; it should probably be split into two arguments.
1229 .It Sy "parenthesis in function name"
1231 The first argument of an
1235 macro contains an opening or closing parenthesis; that's probably wrong,
1236 parentheses are added automatically.
1237 .It Sy "invalid content in Rs block"
1241 block contains plain text or non-% macros.
1242 The bogus content is left in the syntax tree.
1243 Formatting may be poor.
1244 .It Sy "invalid Boolean argument"
1248 macro has an argument other than
1252 The invalid argument is moved out of the macro, which leaves the macro
1253 empty, causing it to toggle the spacing mode.
1254 .It Sy "unknown font, skipping request"
1262 layout modifier has an unknown
1265 .It Sy "odd number of characters in request"
1269 request contains an odd number of characters.
1270 The last character is mapped to the blank character.
1272 .Ss "Warnings related to plain text"
1274 .It Sy "blank line in fill mode, using .sp"
1276 The meaning of blank input lines is only well-defined in non-fill mode:
1277 In fill mode, line breaks of text input lines are not supposed to be
1279 However, for compatibility with groff, blank lines in fill mode
1283 .It Sy "tab in filled text"
1285 The meaning of tab characters is only well-defined in non-fill mode:
1286 In fill mode, whitespace is not supposed to be significant
1287 on text input lines.
1288 As an implementation dependent choice, tab characters on text lines
1289 are passed through to the formatters in any case.
1290 Given that the text before the tab character will be filled,
1291 it is hard to predict which tab stop position the tab will advance to.
1292 .It Sy "whitespace at end of input line"
1293 .Pq mdoc , man , roff
1294 Whitespace at the end of input lines is almost never semantically
1295 significant \(em but in the odd case where it might be, it is
1296 extremely confusing when reviewing and maintaining documents.
1297 .It Sy "bad comment style"
1299 Comment lines start with a dot, a backslash, and a double-quote character.
1302 utility treats the line as a comment line even without the backslash,
1303 but leaving out the backslash might not be portable.
1304 .It Sy "invalid escape sequence"
1306 An escape sequence has an invalid opening argument delimiter, lacks the
1307 closing argument delimiter, or the argument has too few characters.
1308 If the argument is incomplete,
1312 expand to an empty string,
1318 to the length of the incomplete argument.
1319 All other invalid escape sequences are ignored.
1320 .It Sy "undefined string, using \(dq\(dq"
1322 If a string is used without being defined before,
1323 its value is implicitly set to the empty string.
1324 However, defining strings explicitly before use
1325 keeps the code more readable.
1327 .Ss "Warnings related to tables"
1329 .It Sy "tbl line starts with span"
1331 The first cell in a table layout line is a horizontal span
1333 Data provided for this cell is ignored, and nothing is printed in the cell.
1334 .It Sy "tbl column starts with span"
1336 The first line of a table layout specification
1337 requests a vertical span
1339 Data provided for this cell is ignored, and nothing is printed in the cell.
1340 .It Sy "skipping vertical bar in tbl layout"
1342 A table layout specification contains more than two consecutive vertical bars.
1343 A double bar is printed, all additional bars are discarded.
1345 .Ss "Errors related to tables"
1347 .It Sy "non-alphabetic character in tbl options"
1349 The table options line contains a character other than a letter,
1350 blank, or comma where the beginning of an option name is expected.
1351 The character is ignored.
1352 .It Sy "skipping unknown tbl option"
1354 The table options line contains a string of letters that does not
1355 match any known option name.
1356 The word is ignored.
1357 .It Sy "missing tbl option argument"
1359 A table option that requires an argument is not followed by an
1360 opening parenthesis, or the opening parenthesis is immediately
1361 followed by a closing parenthesis.
1362 The option is ignored.
1363 .It Sy "wrong tbl option argument size"
1365 A table option argument contains an invalid number of characters.
1366 Both the option and the argument are ignored.
1367 .It Sy "empty tbl layout"
1369 A table layout specification is completely empty,
1370 specifying zero lines and zero columns.
1371 As a fallback, a single left-justified column is used.
1372 .It Sy "invalid character in tbl layout"
1374 A table layout specification contains a character that can neither
1375 be interpreted as a layout key character nor as a layout modifier,
1376 or a modifier precedes the first key.
1377 The invalid character is discarded.
1378 .It Sy "unmatched parenthesis in tbl layout"
1380 A table layout specification contains an opening parenthesis,
1381 but no matching closing parenthesis.
1382 The rest of the input line, starting from the parenthesis, has no effect.
1383 .It Sy "tbl without any data cells"
1385 A table does not contain any data cells.
1386 It will probably produce no output.
1387 .It Sy "ignoring data in spanned tbl cell"
1389 A table cell is marked as a horizontal span
1393 in the table layout, but it contains data.
1394 The data is ignored.
1395 .It Sy "ignoring extra tbl data cells"
1397 A data line contains more cells than the corresponding layout line.
1398 The data in the extra cells is ignored.
1399 .It Sy "data block open at end of tbl"
1401 A data block is opened with
1403 but never closed with a matching
1405 The remaining data lines of the table are all put into one cell,
1406 and any remaining cells stay empty.
1408 .Ss "Errors related to roff, mdoc, and man code"
1410 .It Sy "input stack limit exceeded, infinite loop?"
1412 Explicit recursion limits are implemented for the following features,
1413 in order to prevent infinite loops:
1416 expansion of nested escape sequences
1417 including expansion of strings and number registers,
1419 expansion of nested user-defined macros,
1425 When a limit is hit, the output is incorrect, typically losing
1426 some content, but the parser can continue.
1427 .It Sy "skipping bad character"
1428 .Pq mdoc , man , roff
1429 The input file contains a byte that is not a printable
1432 The message mentions the character number.
1433 The offending byte is replaced with a question mark
1435 Consider editing the input file to replace the byte with an ASCII
1436 transliteration of the intended character.
1437 .It Sy "skipping unknown macro"
1438 .Pq mdoc , man , roff
1439 The first identifier on a request or macro line is neither recognized as a
1441 request, nor as a user-defined macro, nor, respectively, as an
1446 It may be mistyped or unsupported.
1447 The request or macro is discarded including its arguments.
1448 .It Sy "skipping insecure request"
1450 An input file attempted to run a shell command
1451 or to read or write an external file.
1452 Such attempts are denied for security reasons.
1453 .It Sy "skipping item outside list"
1457 macro occurs outside any
1462 delimiter occurs outside any pile.
1463 It is discarded including its arguments.
1464 .It Sy "skipping column outside column list"
1468 macro occurs outside any
1471 It is discarded including its arguments.
1472 .It Sy "skipping end of block that is not open"
1473 .Pq mdoc , man , eqn , tbl , roff
1474 Various syntax elements can only be used to explicitly close blocks
1475 that have previously been opened.
1478 block closing macro, a
1485 right delimiter or closing brace, or the end of an equation, table, or
1487 conditional request is encountered but no matching block is open.
1488 The offending request or macro is discarded.
1489 .It Sy "fewer RS blocks open, skipping"
1493 macro is invoked with an argument, but less than the specified number of
1499 .It Sy "inserting missing end of block"
1503 macros as well as tables require explicit closing by dedicated macros.
1504 A block that doesn't support bad nesting
1505 ends before all of its children are properly closed.
1506 The open child nodes are closed implicitly.
1507 .It Sy "appending missing end of block"
1508 .Pq mdoc , man , eqn , tbl , roff
1509 At the end of the document, an explicit
1517 block, an equation, table, or
1519 conditional or ignore block is still open.
1520 The open block is closed implicitly.
1521 .It Sy "escaped character not allowed in a name"
1523 Macro, string and register identifiers consist of printable,
1524 non-whitespace ASCII characters.
1525 Escape sequences and characters and strings expressed in terms of them
1526 cannot form part of a name.
1527 The first argument of an
1535 request, or any argument of an
1537 request, or the name of a request or user defined macro being called,
1538 is terminated by an escape sequence.
1544 the request has no effect at all.
1551 what was parsed up to this point is used as the arguments to the request,
1552 and the rest of the input line is discarded including the escape sequence.
1553 When parsing for a request or a user-defined macro name to be called,
1554 only the escape sequence is discarded.
1555 The characters preceding it are used as the request or macro name,
1556 the characters following it are used as the arguments to the request or macro.
1557 .It Sy "NOT IMPLEMENTED: Bd -file"
1559 For security reasons, the
1561 macro does not support the
1564 By requesting the inclusion of a sensitive file, a malicious document
1565 might otherwise trick a privileged user into inadvertently displaying
1566 the file on the screen, revealing the file content to bystanders.
1567 The argument is ignored including the file name following it.
1568 .It Sy "missing list type, using -item"
1572 macro fails to specify the list type.
1573 .It Sy "missing manual name, using \(dq\(dq"
1577 lacks the required argument.
1578 .It Sy "uname(3) system call failed, using UNKNOWN"
1582 macro is called without arguments, and the
1587 can be compiled with
1589 .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
1591 .It Sy "unknown standard specifier"
1595 macro has an unknown argument and is discarded.
1596 .It Sy "skipping request without numeric argument"
1605 statement has a non-numeric or negative argument or no argument at all.
1606 The invalid request or statement is ignored.
1607 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
1609 For security reasons,
1613 file inclusion requests only with relative paths
1614 and only without ascending to any parent directory.
1615 By requesting the inclusion of a sensitive file, a malicious document
1616 might otherwise trick a privileged user into inadvertently displaying
1617 the file on the screen, revealing the file content to bystanders.
1619 only shows the path as it appears behind
1621 .It Sy ".so request failed"
1625 request requires reading an external file, but the file could not be
1628 only shows the path as it appears behind
1630 .It Sy "skipping all arguments"
1631 .Pq mdoc , man , eqn , roff
1647 macro in a list that don't support item heads, a
1666 block closing request is invoked with at least one argument.
1667 All arguments are ignored.
1668 .It Sy "skipping excess arguments"
1669 .Pq mdoc , man , roff
1670 A macro or request is invoked with too many arguments:
1671 .Bl -dash -offset 2n -width 2n -compact
1680 with more than one argument
1683 with another argument after
1689 with more than one argument or with a non-integer argument
1694 family with more than two arguments
1697 with more than three arguments
1700 with more than five arguments
1706 with invalid arguments
1708 The excess arguments are ignored.
1710 .Ss Unsupported features
1712 .It Sy "input too large"
1716 cannot handle input files larger than its arbitrary size limit
1717 of 2^31 bytes (2 Gigabytes).
1718 Since useful manuals are always small, this is not a problem in practice.
1719 Parsing is aborted as soon as the condition is detected.
1720 .It Sy "unsupported control character"
1722 An ASCII control character supported by other
1724 implementations but not by
1726 was found in an input file.
1727 It is replaced by a question mark.
1728 .It Sy "unsupported roff request"
1730 An input file contains a
1732 request supported by GNU troff or Heirloom troff but not by
1734 and it is likely that this will cause information loss
1735 or considerable misformatting.
1736 .It Sy "eqn delim option in tbl"
1738 The options line of a table defines equation delimiters.
1739 Any equation source code contained in the table will be printed unformatted.
1740 .It Sy "unsupported table layout modifier"
1742 A table layout specification contains an
1745 The modifier is discarded.
1746 .It Sy "ignoring macro in table"
1747 .Pq tbl , mdoc , man
1748 A table contains an invocation of an
1752 macro or of an undefined macro.
1753 The macro is ignored, and its arguments are handled
1754 as if they were a text line.
1769 utility was written by
1770 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1771 and is maintained by
1772 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .
1776 the maximum size of an element attribute is determined by
1778 which is usually 1024 bytes.
1779 Be aware of this when setting long link
1781 .Fl O Cm style Ns = Ns Ar really/long/link .