===================================================================
RCS file: /cvs/mandoc/mandoc.1,v
retrieving revision 1.231
retrieving revision 1.258
diff -u -p -r1.231 -r1.258
--- mandoc/mandoc.1	2018/11/22 11:30:23	1.231
+++ mandoc/mandoc.1	2022/04/28 16:21:09	1.258
@@ -1,7 +1,7 @@
-.\"	$Id: mandoc.1,v 1.231 2018/11/22 11:30:23 schwarze Exp $
+.\" $Id: mandoc.1,v 1.258 2022/04/28 16:21:09 schwarze Exp $
 .\"
+.\" Copyright (c) 2012, 2014-2022 Ingo Schwarze <schwarze@openbsd.org>
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
-.\" Copyright (c) 2012, 2014-2018 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 22 2018 $
+.Dd $Mdocdate: April 28 2022 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -52,13 +52,13 @@ The options are as follows:
 If the standard output is a terminal device and
 .Fl c
 is not specified, use
-.Xr more 1
+.Xr less 1
 to paginate the output, just like
 .Xr man 1
 would.
 .It Fl c
 Copy the formatted manual pages to the standard output without using
-.Xr more 1
+.Xr less 1
 to paginate them.
 This is the default.
 It can be specified to override
@@ -222,7 +222,8 @@ reads from standard input.
 .Pp
 The options
 .Fl fhklw
-are also supported and are documented in man(1).
+are also supported and are documented in
+.Xr man 1 .
 In
 .Fl f
 and
@@ -256,10 +257,28 @@ where
 is the back-space character number 8.
 Emboldened characters are rendered as
 .Sq c Ns \e[bs] Ns c .
+This markup is typically converted to appropriate terminal sequences by
+the pager or
+.Xr ul 1 .
+To remove the markup, pipe the output to
+.Xr col 1
+.Fl b
+instead.
 .Pp
 The special characters documented in
 .Xr mandoc_char 7
 are rendered best-effort in an ASCII equivalent.
+In particular, opening and closing
+.Sq single quotes
+are represented as characters number 0x60 and 0x27, respectively,
+which agrees with all ASCII standards from 1965 to the latest
+revision (2012) and which matches the traditional way in which
+.Xr roff 7
+formatters represent single quotes in ASCII output.
+This correct ASCII rendering may look strange with modern
+Unicode-compatible fonts because contrary to ASCII, Unicode uses
+the code point U+0060 for the grave accent only, never for an opening
+quote.
 .Pp
 The following
 .Fl O
@@ -282,8 +301,8 @@ Format
 input files in
 .Xr mdoc 7
 output style.
-Specifically, this suppresses the two additional blank lines near the
-top and the bottom of each page, and it implies
+This prints the operating system name rather than the page title
+on the right side of the footer line, and it implies
 .Fl O Cm indent Ns =5 .
 One useful application is for checking that
 .Fl T Cm man
@@ -300,8 +319,16 @@ If no
 is specified, reuse the first command line argument that is not a
 .Ar section
 number.
-This is useful when it is the name of a manual page,
-in particular the name of a library function.
+If that argument is in
+.Xr apropos 1
+.Ar key Ns = Ns Ar val
+format, only the
+.Ar val
+is used rather than the argument as a whole.
+This is useful for commands like
+.Ql man -akO tag Ic=ulimit
+to search for a keyword and jump right to its definition
+in the matching manual pages.
 .It Cm width Ns = Ns Ar width
 The output width is set to
 .Ar width
@@ -320,9 +347,9 @@ Equations rendered from
 .Xr eqn 7
 blocks use MathML.
 .Pp
-The
-.Pa mandoc.css
-file documents style-sheet classes available for customising output.
+The file
+.Pa /usr/share/misc/mandoc.css
+documents style-sheet classes available for customising output.
 If a style-sheet is not specified with
 .Fl O Cm style ,
 .Fl T Cm html
@@ -383,6 +410,30 @@ The file
 is used for an external style-sheet.
 This must be a valid absolute or
 relative URI.
+.It Cm tag Ns Op = Ns Ar term
+Same syntax and semantics as for
+.Sx ASCII Output .
+This is implemented by passing a
+.Ic file://
+URI ending in a fragment identifier to the pager
+rather than passing merely a file name.
+When using this argument, use a pager supporting such URIs, for example
+.Bd -literal -offset 3n
+MANPAGER='lynx -force_html' man -T html -O tag=MANPAGER man
+MANPAGER='w3m -T text/html' man -T html -O tag=toc mandoc
+.Ed
+.Pp
+Consequently, for HTML output, this argument does not work with
+.Xr more 1
+or
+.Xr less 1 .
+For example,
+.Ql MANPAGER=less man -T html -O tag=toc mandoc
+does not work because
+.Xr less 1
+does not support
+.Ic file://
+URIs.
 .It Cm toc
 If an input file contains at least two non-standard sections,
 print a table of contents near the beginning of the output.
@@ -416,13 +467,15 @@ This is useful for distributing manual sources to lega
 lacking
 .Xr mdoc 7
 formatters.
+Embedded
+.Xr eqn 7
+and
+.Xr tbl 7
+code is not supported.
 .Pp
 If the input format of a file is
 .Xr man 7 ,
-the input is copied to the output, expanding any
-.Xr roff 7
-.Ic so
-requests.
+the input is copied to the output.
 The parser is also run, and as usual, the
 .Fl W
 level controls which
@@ -434,10 +487,10 @@ Use
 to translate
 .Xr mdoc 7
 input to the markdown format conforming to
-.Lk http://daringfireball.net/projects/markdown/syntax.text\
+.Lk https://daringfireball.net/projects/markdown/syntax.text\
  "John Gruber's 2004 specification" .
 The output also almost conforms to the
-.Lk http://commonmark.org/ CommonMark
+.Lk https://commonmark.org/ CommonMark
 specification.
 .Pp
 The character set used for the markdown output is ASCII.
@@ -601,7 +654,7 @@ It never affects the interpretation of input files.
 Any non-empty value of the environment variable
 .Ev MANPAGER
 is used instead of the standard pagination program,
-.Xr more 1 ;
+.Xr less 1 ;
 see
 .Xr man 1
 for details.
@@ -615,8 +668,7 @@ Specifies the pagination program to use when
 .Ev MANPAGER
 is not defined.
 If neither PAGER nor MANPAGER is defined,
-.Xr more 1
-.Fl s
+.Xr less 1
 is used.
 Only used if
 .Fl a
@@ -671,7 +723,7 @@ No input files have been read.
 .It 6
 An operating system error occurred, for example exhaustion
 of memory, file descriptors, or process table entries.
-Such errors cause
+Such errors may cause
 .Nm
 to exit at once, possibly in the middle of parsing or formatting a file.
 .El
@@ -683,13 +735,13 @@ output mode implies
 .Sh EXAMPLES
 To page manuals to the terminal:
 .Pp
-.Dl $ mandoc -l mandoc.1 man.1 apropos.1 makewhatis.8
+.Dl $ mandoc -a mandoc.1 man.1 apropos.1 makewhatis.8
 .Pp
 To produce HTML manuals with
-.Pa mandoc.css
+.Pa /usr/share/misc/mandoc.css
 as the style-sheet:
 .Pp
-.Dl $ mandoc \-T html -O style=mandoc.css mdoc.7 \*(Gt mdoc.7.html
+.Dl $ mandoc \-T html -O style=/usr/share/misc/mandoc.css mdoc.7 > mdoc.7.html
 .Pp
 To check over a large set of manuals:
 .Pp
@@ -697,7 +749,7 @@ To check over a large set of manuals:
 .Pp
 To produce a series of PostScript manuals for A4 paper:
 .Pp
-.Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
+.Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 > manuals.ps
 .Pp
 Convert a modern
 .Xr mdoc 7
@@ -707,20 +759,36 @@ format, for use on systems lacking an
 .Xr mdoc 7
 parser:
 .Pp
-.Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
+.Dl $ mandoc \-T man foo.mdoc > foo.man
 .Sh DIAGNOSTICS
 Messages displayed by
 .Nm
 follow this format:
 .Bd -ragged -offset indent
 .Nm :
-.Ar file : Ns Ar line : Ns Ar column : level : message : macro args
+.Ar file : Ns Ar line : Ns Ar column : level : message : macro arguments
 .Pq Ar os
 .Ed
 .Pp
-Line and column numbers start at 1.
+The first three fields identify the
+.Ar file
+name,
+.Ar line
+number, and
+.Ar column
+number of the input file where the message was triggered.
+The line and column numbers start at 1.
 Both are omitted for messages referring to an input file as a whole.
-Macro names and arguments are omitted where meaningless.
+All
+.Ar level
+and
+.Ar message
+strings are explained below.
+The name of the
+.Ar macro
+triggering the message and its
+.Ar arguments
+are omitted where meaningless.
 The
 .Ar os
 operating system specifier is omitted for messages that are relevant
@@ -735,6 +803,13 @@ fields.
 .Pp
 Message levels have the following meanings:
 .Bl -tag -width "warning"
+.It Cm syserr
+An operating system error occurred.
+There isn't necessarily anything wrong with the input files.
+Output may all the same be missing or incomplete.
+.It Cm badarg
+Invalid command line arguments were specified.
+No input files have been read and no output is produced.
 .It Cm unsupp
 An input file uses unsupported low-level
 .Xr roff 7
@@ -760,7 +835,7 @@ message levels, the
 .Cm style
 level tries to reduce the probability that issues go unnoticed,
 so it may occasionally issue bogus suggestions.
-Please use your good judgement to decide whether any particular
+Use your judgement to decide whether any particular
 .Cm style
 suggestion really justifies a change to the input file.
 .It Cm base
@@ -783,8 +858,7 @@ Messages of the
 .Cm error ,
 and
 .Cm unsupp
-levels except those about non-existent or unreadable input files
-are hidden unless their level, or a lower level, is requested using a
+levels are hidden unless their level, or a lower level, is requested using a
 .Fl W
 option or
 .Fl T Cm lint
@@ -848,14 +922,6 @@ generated by CVS
 or
 .Ic NetBSD
 keyword substitution as conventionally used in these operating systems.
-.It Sy "referenced manual not found"
-.Pq mdoc
-An
-.Ic \&Xr
-macro references a manual page that is not found in the base system.
-The path to look for base system manuals is configurable at compile
-time and defaults to
-.Pa /usr/share/man : /usr/X11R6/man .
 .El
 .Ss Style suggestions
 .Bl -ohang
@@ -942,6 +1008,35 @@ list contains two consecutive
 entries describing the same
 .Ic \&Er
 number.
+.It Sy "referenced manual not found"
+.Pq mdoc
+An
+.Ic \&Xr
+macro references a manual page that was not found.
+When running with
+.Fl W Cm base ,
+the search is restricted to the base system, by default to
+.Pa /usr/share/man : Ns Pa /usr/X11R6/man .
+This path can be configured at compile time using the
+.Dv MANPATH_BASE
+preprocessor macro.
+When running with
+.Fl W Cm style ,
+the search is done along the full search path as described in the
+.Xr man 1
+manual page, respecting the
+.Fl m
+and
+.Fl M
+command line options, the
+.Ev MANPATH
+environment variable, the
+.Xr man.conf 5
+file and falling back to the default of
+.Pa /usr/share/man : Ns Pa /usr/X11R6/man : Ns Pa /usr/local/man ,
+also configurable at compile time using the
+.Dv MANPATH_DEFAULT
+preprocessor macro.
 .It Sy "trailing delimiter"
 .Pq mdoc
 The last argument of an
@@ -971,6 +1066,9 @@ An
 request occurs even though the document already switched to no-fill mode
 and did not switch back to fill mode yet.
 It has no effect.
+.It Sy "input text line longer than 80 bytes"
+Consider breaking the input text line
+at one of the blank characters before column 80.
 .It Sy "verbatim \(dq--\(dq, maybe consider using \e(em"
 .Pq mdoc
 Even though the ASCII output device renders an em-dash as
@@ -1024,7 +1122,21 @@ macro lacks the mandatory section argument.
 The section number in a
 .Ic \&Dt
 line is invalid, but still used.
-.It Sy "missing date, using today's date"
+.It Sy "filename/section mismatch"
+.Pq mdoc , man
+The name of the input file being processed is known and its file
+name extension starts with a non-zero digit, but the
+.Ic \&Dt
+or
+.Ic \&TH
+macro contains a
+.Ar section
+argument that starts with a different non-zero digit.
+The
+.Ar section
+argument is used as provided anyway.
+Consider checking whether the file name or the argument need a correction.
+.It Sy "missing date, using \(dq\(dq"
 .Pq mdoc, man
 The document was parsed as
 .Xr mdoc 7
@@ -1642,6 +1754,15 @@ request or a
 layout modifier has an unknown
 .Ar font
 argument.
+.It Sy "ignoring distance argument"
+.Pq roff
+In addition to the margin character, an
+.Ic \&mc
+request has a second argument supposed to represent a distance, but the
+.Nm
+implementation of
+.Ic \&mc
+always ignores the second argument.
 .It Sy "odd number of characters in request"
 .Pq roff
 A
@@ -1657,9 +1778,12 @@ The meaning of blank input lines is only well-defined 
 In fill mode, line breaks of text input lines are not supposed to be
 significant.
 However, for compatibility with groff, blank lines in fill mode
-are replaced with
+are formatted like
 .Ic \&sp
 requests.
+To request a paragraph break, use
+.Ic \&Pp
+instead of a blank line.
 .It Sy "tab in filled text"
 .Pq mdoc , man
 The meaning of tab characters is only well-defined in non-fill mode:
@@ -1676,7 +1800,8 @@ Start it on a new input line to help formatters produc
 .It Sy "invalid escape sequence"
 .Pq roff
 An escape sequence has an invalid opening argument delimiter, lacks the
-closing argument delimiter, or the argument has too few characters.
+closing argument delimiter, the argument is of an invalid form, or it is
+a character escape sequence with an invalid name.
 If the argument is incomplete,
 .Ic \e*
 and
@@ -1689,6 +1814,12 @@ and
 .Ic \ew
 to the length of the incomplete argument.
 All other invalid escape sequences are ignored.
+.It Sy "undefined escape, printing literally"
+.Pq roff
+In an escape sequence, the first character
+right after the leading backslash is invalid.
+That character is printed literally,
+which is equivalent to ignoring the backslash.
 .It Sy "undefined string, using \(dq\(dq"
 .Pq roff
 If a string is used without being defined before,
@@ -1752,6 +1883,10 @@ The invalid character is discarded.
 A table layout specification contains an opening parenthesis,
 but no matching closing parenthesis.
 The rest of the input line, starting from the parenthesis, has no effect.
+.It Sy "ignoring excessive spacing in tbl layout"
+.Pq tbl
+A spacing modifier in a table layout is unreasonably large.
+The default spacing of 3n is used instead.
 .It Sy "tbl without any data cells"
 .Pq tbl
 A table does not contain any data cells.
@@ -1956,6 +2091,13 @@ and expands to the empty string.
 .Pq roff
 The argument of the escape sequence \e$ is not a digit;
 the escape sequence expands to the empty string.
+.It Sy "negative argument, using 0"
+.Pq roff
+A
+.Ic \&shift
+request has a negative argument
+or an argument that is negative due to integer overflow.
+Macro argument numbering remains unchanged.
 .It Sy "NOT IMPLEMENTED: Bd -file"
 .Pq mdoc
 For security reasons, the
@@ -1991,6 +2133,13 @@ The first argument of a
 request is neither a single ASCII character
 nor a single character escape sequence.
 The request is ignored including all its arguments.
+.It Sy "skipping unusable escape sequence"
+.Pq roff
+The first argument of an
+.Ic mc
+request is neither a single ASCII character
+nor a single character escape sequence.
+All arguments are ignored and printing of a margin character is disabled.
 .It Sy "missing manual name, using \(dq\(dq"
 .Pq mdoc
 The first call to
@@ -2154,6 +2303,13 @@ implementations but not by
 .Nm
 was found in an input file.
 It is replaced by a question mark.
+.It Sy "unsupported escape sequence"
+.Pq roff
+An input file contains an escape sequence supported by GNU troff
+or Heirloom troff but not by
+.Nm ,
+and it is likely that this will cause information loss
+or considerable misformatting.
 .It Sy "unsupported roff request"
 .Pq roff
 An input file contains a
@@ -2181,6 +2337,71 @@ or
 macro or of an undefined macro.
 The macro is ignored, and its arguments are handled
 as if they were a text line.
+.It Sy "skipping tbl in -Tman mode"
+.Pq mdoc , tbl
+An input file contains the
+.Ic \&TS
+macro.
+This message is only generated in
+.Fl T Cm man
+output mode, where
+.Xr tbl 7
+input is not supported.
+.It Sy "skipping eqn in -Tman mode"
+.Pq mdoc , eqn
+An input file contains the
+.Ic \&EQ
+macro.
+This message is only generated in
+.Fl T Cm man
+output mode, where
+.Xr eqn 7
+input is not supported.
+.El
+.Ss Bad command line arguments
+.Bl -ohang
+.It Sy "bad command line argument"
+The argument following one of the
+.Fl IKMmOTW
+command line options is invalid, or a
+.Ar file
+given as a command line argument cannot be opened.
+.It Sy "duplicate command line argument"
+The
+.Fl I
+command line option was specified twice.
+.It Sy "option has a superfluous value"
+An argument to the
+.Fl O
+option has a value but does not accept one.
+.It Sy "missing option value"
+An argument to the
+.Fl O
+option has no argument but requires one.
+.It Sy "bad option value"
+An argument to the
+.Fl O
+.Cm indent
+or
+.Cm width
+option has an invalid value.
+.It Sy "duplicate option value"
+The same
+.Fl O
+option is specified more than once.
+.It Sy "no such tag"
+The
+.Fl O Cm tag
+option was specified but the tag was not found in any of the displayed
+manual pages.
+.It Sy "\-Tmarkdown unsupported for man(7) input"
+.Pq man
+The
+.Fl T Cm markdown
+option was specified but an input file uses the
+.Xr man 7
+language.
+No output is produced for that input file.
 .El
 .Sh SEE ALSO
 .Xr apropos 1 ,