===================================================================
RCS file: /cvs/mandoc/mandoc.1,v
retrieving revision 1.223
retrieving revision 1.244
diff -u -p -r1.223 -r1.244
--- mandoc/mandoc.1	2018/04/13 19:55:30	1.223
+++ mandoc/mandoc.1	2020/06/15 18:05:18	1.244
@@ -1,7 +1,7 @@
-.\"	$Id: mandoc.1,v 1.223 2018/04/13 19:55:30 schwarze Exp $
+.\" $OpenBSD: mandoc.1,v 1.244 2020/06/15 18:05:18 schwarze Exp $
 .\"
+.\" Copyright (c) 2012, 2014-2020 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: April 13 2018 $
+.Dd $Mdocdate: June 15 2020 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -34,9 +34,7 @@
 .Sh DESCRIPTION
 The
 .Nm
-utility formats
-.Ux
-manual pages for display.
+utility formats manual pages for display.
 .Pp
 By default,
 .Nm
@@ -132,13 +130,32 @@ With other arguments,
 is silently ignored.
 .It Fl O Ar options
 Comma-separated output options.
+See the descriptions of the individual output formats for supported
+.Ar options .
 .It Fl T Ar output
-Output format.
-See
-.Sx Output Formats
-for available formats.
-Defaults to
-.Fl T Cm locale .
+Select the output format.
+Supported values for the
+.Ar output
+argument are
+.Cm ascii ,
+.Cm html ,
+the default of
+.Cm locale ,
+.Cm man ,
+.Cm markdown ,
+.Cm pdf ,
+.Cm ps ,
+.Cm tree ,
+and
+.Cm utf8 .
+.Pp
+The special
+.Fl T Cm lint
+mode only parses the input and produces no output.
+It implies
+.Fl W Cm all
+and redirects parser messages, which usually appear on standard
+error output, to standard output.
 .It Fl W Ar level
 Specify the minimum message
 .Ar level
@@ -196,16 +213,17 @@ and
 are requested, they can be joined with a comma, for example
 .Fl W Cm error , Ns Cm stop .
 .It Ar file
-Read input from zero or more files.
-If unspecified, reads from stdin.
-If multiple files are specified,
+Read from the given input file.
+If multiple files are specified, they are processed in the given order.
+If unspecified,
 .Nm
-will halt with the first failed parse.
+reads from standard input.
 .El
 .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
@@ -220,69 +238,14 @@ manual.
 The options
 .Fl fkl
 are mutually exclusive and override each other.
-.Ss Output Formats
-The
-.Nm
-utility accepts the following
-.Fl T
-arguments, which correspond to output modes:
-.Bl -tag -width "-T markdown"
-.It Fl T Cm ascii
-Produce 7-bit ASCII output.
-See
-.Sx ASCII Output .
-.It Fl T Cm html
-Produce HTML5, CSS1, and MathML output.
-See
-.Sx HTML Output .
-.It Fl T Cm lint
-Parse only: produce no output.
-Implies
-.Fl W Cm all
-and redirects parser messages, which usually appear
-on standard error output, to standard output.
-.It Fl T Cm locale
-Encode output using the current locale.
-This is the default.
-See
-.Sx Locale Output .
-.It Fl T Cm man
-Produce
-.Xr man 7
-format output.
-See
-.Sx Man Output .
-.It Fl T Cm markdown
-Produce output in
-.Sy markdown
-format.
-See
-.Sx Markdown Output .
-.It Fl T Cm pdf
-Produce PDF output.
-See
-.Sx PDF Output .
-.It Fl T Cm ps
-Produce PostScript output.
-See
-.Sx PostScript Output .
-.It Fl T Cm tree
-Produce an indented parse tree.
-See
-.Sx Syntax tree output .
-.It Fl T Cm utf8
-Encode output in the UTF\-8 multi-byte format.
-See
-.Sx UTF\-8 Output .
-.El
-.Pp
-If multiple input files are specified, these will be processed by the
-corresponding filter in-order.
 .Ss ASCII Output
-Output produced by
+Use
 .Fl T Cm ascii
-is rendered in standard 7-bit ASCII documented in
-.Xr ascii 7 .
+to force text output in 7-bit ASCII character encoding documented in the
+.Xr ascii 7
+manual page, ignoring the
+.Xr locale 1
+set in the environment.
 .Pp
 Font styles are applied by using back-spaced encoding such that an
 underlined character
@@ -294,10 +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
@@ -328,6 +309,26 @@ One useful application is for checking that
 output formats in the same way as the
 .Xr mdoc 7
 source it was generated from.
+.It Cm tag Ns Op = Ns Ar term
+If the formatted manual page is opened in a pager,
+go to the definition of the
+.Ar term
+rather than showing the manual page from the beginning.
+If no
+.Ar term
+is specified, reuse the first command line argument that is not a
+.Ar section
+number.
+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
@@ -346,9 +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
@@ -356,7 +357,8 @@ defaults to simple output (via an embedded style-sheet
 readable in any graphical or text-based web
 browser.
 .Pp
-Special characters are rendered in decimal-encoded UTF\-8.
+Non-ASCII characters are rendered
+as hexadecimal Unicode character references.
 .Pp
 The following
 .Fl O
@@ -382,7 +384,7 @@ Instances of
 are replaced with the include filename.
 The default is not to present a
 hyperlink.
-.It Cm man Ns = Ns Ar fmt
+.It Cm man Ns = Ns Ar fmt Ns Op ; Ns Ar fmt
 The string
 .Ar fmt ,
 for example,
@@ -398,39 +400,73 @@ are replaced with the linked manual's name and section
 If no section is included, section 1 is assumed.
 The default is not to
 present a hyperlink.
+If two formats are given and a file
+.Ar %N.%S
+exists in the current directory, the first format is used;
+otherwise, the second format is used.
 .It Cm style Ns = Ns Ar style.css
 The file
 .Ar style.css
 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
+This argument does not work with
+.Xr more 1
+or
+.Xr less 1 .
+.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.
 .El
 .Ss Locale Output
-Locale-depending output encoding is triggered with
+By default,
+.Nm
+automatically selects UTF-8 or ASCII output according to the current
+.Xr locale 1 .
+If any of the environment variables
+.Ev LC_ALL ,
+.Ev LC_CTYPE ,
+or
+.Ev LANG
+are set and the first one that is set
+selects the UTF-8 character encoding, it produces
+.Sx UTF-8 Output ;
+otherwise, it falls back to
+.Sx ASCII Output .
+This output mode can also be selected explicitly with
 .Fl T Cm locale .
-This is the default.
-.Pp
-This option is not available on all systems: systems without locale
-support, or those whose internal representation is not natively UCS-4,
-will fall back to
-.Fl T Cm ascii .
-See
-.Sx ASCII Output
-for font style specification and available command-line arguments.
 .Ss Man Output
-Translate input format into
+Use
+.Fl T Cm man
+to translate
+.Xr mdoc 7
+input into
 .Xr man 7
 output format.
 This is useful for distributing manual sources to legacy systems
 lacking
 .Xr mdoc 7
 formatters.
+Embedded
+.Xr eqn 7
+and
+.Xr tbl 7
+code is not supported.
 .Pp
-If
-.Xr mdoc 7
-is passed as input, it is translated into
-.Xr man 7 .
-If the input format is
+If the input format of a file is
 .Xr man 7 ,
 the input is copied to the output, expanding any
 .Xr roff 7
@@ -442,11 +478,11 @@ level controls which
 .Sx DIAGNOSTICS
 are displayed before copying the input to the output.
 .Ss Markdown Output
-Translate
+Use
+.Fl T Cm markdown
+to translate
 .Xr mdoc 7
-input to the
-.Sy markdown
-format conforming to
+input to the markdown format conforming to
 .Lk http://daringfireball.net/projects/markdown/syntax.text\
  "John Gruber's 2004 specification" .
 The output also almost conforms to the
@@ -517,13 +553,24 @@ If an unknown value is encountered,
 .Ar letter
 is used.
 .El
-.Ss UTF\-8 Output
+.Ss UTF-8 Output
 Use
 .Fl T Cm utf8
-to force a UTF\-8 locale.
+to force text output in UTF-8 multi-byte character encoding,
+ignoring the
+.Xr locale 1
+settings in the environment.
 See
-.Sx Locale Output
-for details and options.
+.Sx ASCII Output
+regarding font styles and
+.Fl O
+arguments.
+.Pp
+On operating systems lacking locale or wide character support, and
+on those where the internal character representation is not UCS-4,
+.Nm
+always falls back to
+.Sx ASCII Output .
 .Ss Syntax tree output
 Use
 .Fl T Cm tree
@@ -592,6 +639,13 @@ Meta data is not available in this case.
 .El
 .Sh ENVIRONMENT
 .Bl -tag -width MANPAGER
+.It Ev LC_CTYPE
+The character encoding
+.Xr locale 1 .
+When
+.Sx Locale Output
+is selected, it decides whether to use ASCII or UTF-8 output format.
+It never affects the interpretation of input files.
 .It Ev MANPAGER
 Any non-empty value of the environment variable
 .Ev MANPAGER
@@ -666,7 +720,7 @@ 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
@@ -681,10 +735,10 @@ To page manuals to the terminal:
 .Dl $ mandoc -l 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
@@ -692,7 +746,7 @@ 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
@@ -702,20 +756,36 @@ 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
@@ -730,6 +800,13 @@ 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
@@ -778,8 +855,7 @@ 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
@@ -867,6 +943,16 @@ Consider using the conventional
 date format
 .Dq "Month dd, yyyy"
 instead.
+.It Sy "normalizing date format to" : No ...
+.Pq mdoc , man
+The
+.Ic \&Dd
+or
+.Ic \&TH
+macro provides an abbreviated month name or a day number with a
+leading zero.
+In the formatted output, the month name is written out in full
+and the leading zero is omitted.
 .It Sy "lower case character in document title"
 .Pq mdoc , man
 The title is still used as given in the
@@ -1009,7 +1095,21 @@ 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
@@ -1610,6 +1710,12 @@ or
 .Cm off .
 The invalid argument is moved out of the macro, which leaves the macro
 empty, causing it to toggle the spacing mode.
+.It Sy "argument contains two font escapes"
+.Pq roff
+The second argument of a
+.Ic char
+request contains more than one font escape sequence.
+A wrong font may remain active after using the character.
 .It Sy "unknown font, skipping request"
 .Pq man , tbl
 A
@@ -1636,9 +1742,12 @@ 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:
@@ -1655,7 +1764,8 @@ 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
@@ -1668,6 +1778,12 @@ 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,
@@ -1811,6 +1927,13 @@ or
 macro.
 It may be mistyped or unsupported.
 The request or macro is discarded including its arguments.
+.It Sy "skipping request outside macro"
+.Pq roff
+A
+.Ic shift
+or
+.Ic return
+request occurs outside any macro definition and has no effect.
 .It Sy "skipping insecure request"
 .Pq roff
 An input file attempted to run a shell command
@@ -1920,6 +2043,14 @@ When parsing for a request or a user-defined macro nam
 only the escape sequence is discarded.
 The characters preceding it are used as the request or macro name,
 the characters following it are used as the arguments to the request or macro.
+.It Sy "using macro argument outside macro"
+.Pq roff
+The escape sequence \e$ occurs outside any macro definition
+and expands to the empty string.
+.It Sy "argument number is not numeric"
+.Pq roff
+The argument of the escape sequence \e$ is not a digit;
+the escape sequence expands to the empty string.
 .It Sy "NOT IMPLEMENTED: Bd -file"
 .Pq mdoc
 For security reasons, the
@@ -1948,6 +2079,13 @@ macro fails to specify the list type.
 The argument of a
 .Ic \&ce
 request is not a number.
+.It Sy "argument is not a character"
+.Pq roff
+The first argument of a
+.Ic char
+request is neither a single ASCII character
+nor a single character escape sequence.
+The request is ignored including all its arguments.
 .It Sy "missing manual name, using \(dq\(dq"
 .Pq mdoc
 The first call to
@@ -1982,6 +2120,13 @@ or
 .Ic \&gsize
 statement has a non-numeric or negative argument or no argument at all.
 The invalid request or statement is ignored.
+.It Sy "excessive shift"
+.Pq roff
+The argument of a
+.Ic shift
+request is larger than the number of arguments of the macro that is
+currently being executed.
+All macro arguments are deleted and \en(.$ is set to zero.
 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
 .Pq roff
 For security reasons,
@@ -2104,6 +2249,13 @@ 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
@@ -2131,6 +2283,43 @@ or
 macro or of an undefined macro.
 The macro is ignored, and its arguments are handled
 as if they were a text line.
+.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.
 .El
 .Sh SEE ALSO
 .Xr apropos 1 ,