Ubuntu Manpage: tbl - tbl language reference for mandoc

NAME

       tbl - tbl language reference for mandoc

DESCRIPTION

The tbl language formats tables. It is used within mdoc(7) and man(7) pages. This manual
describes the subset of the tbl language accepted by the mandoc(1) utility.

Each table is started with a roff(7) TS macro, consist of at most one line of Options, one
or more Layout lines, one or more Data lines, and ends with a TE macro. All input must be
7-bit ASCII.

Options
If the first input line of a table ends with a semicolon, it contains case-insensitive
options separated by spaces, tabs, or commas. Otherwise, it is interpreted as the first
Layout line.

The following options are available. Some of them require arguments enclosed in
parentheses:

allbox Draw a single-line box around each table cell.

box Draw a single-line box around the table. For GNU compatibility, this may also be
invoked with frame.

center Center the table instead of left-adjusting it. For GNU compatibility, this may
also be invoked with centre.

decimalpoint
Use the single-character argument as the decimal point with the n layout key.
This is a GNU extension.

delim Use the two characters of the argument as eqn(7) delimiters. Currently
unsupported.

doublebox
Draw a double-line box around the table. For GNU compatibility, this may also be
invoked with doubleframe.

expand Increase the width of the table to the current line length. Currently ignored.

linesize
Draw lines with the point size given by the unsigned integer argument. Currently
ignored.

nokeep Allow page breaks within the table. This is a GNU extension and currently
ignored.

nospaces
Ignore leading and trailing spaces in data cells. This is a GNU extension.

nowarn Suppress warnings about tables exceeding the current line length. This is a GNU
extension and currently ignored.

tab Use the single-character argument as a delimiter between data cells. By default,
the horizontal tabulator character is used.

Layout
The table layout follows an Options line or a roff(7) TS or T& macro. Each layout line
specifies how one line of Data is formatted. The last layout line ends with a full stop.
It also applies to all remaining data lines. Multiple layout lines can be joined by
commas on a single physical input line.

Each layout line consists of one or more layout cell specifications, optionally separated
by whitespace. The following case-insensitive key characters start a new cell
specification:

c Center the string in this cell.

r Right-justify the string in this cell.

l Left-justify the string in this cell.

n Justify a number around its last decimal point. If no decimal point is found in the
number, it is assumed to trail the number.

s Horizontally span columns from the last non-s layout cell. It is an error if a column
span follows a _ or = cell, or comes first on a layout line. The combined cell as a
whole consumes only one cell of the corresponding data line.

a Left-justify a string and pad with one space.

^ Vertically span rows from the last non-^ layout cell. It is an error to invoke a
vertical span on the first layout line. Unlike a horizontal span, a vertical span
consumes a data cell and discards the content.

_ Draw a single horizontal line in this cell. This consumes a data cell and discards
the content. It may also be invoked with -.

= Draw a double horizontal line in this cell. This consumes a data cell and discards
the content.

Each cell key may be followed by zero or more of the following case-insensitive modifiers:

b Use a bold font for the contents of this cell.

d Move content down to the last row of this vertical span. Currently ignored.

e Make this column wider to match the maximum width of any other column also having the
e modifier.

f The next one or two characters select the font to use for this cell. One-character
font names must be followed by a blank or period. See the roff(7) manual for
supported font names.

i Use an italic font for the contents of this cell.

m Specify a cell start macro. This is a GNU extension and currently unsupported.

p Set the point size to the following unsigned argument, or change it by the following
signed argument. Currently ignored.

v Set the vertical line spacing to the following unsigned argument, or change it by the
following signed argument. Currently ignored.

t Do not vertically center content in this vertical span, leave it in the top row.
Currently ignored.

u Move cell content up by half a table row. Currently ignored.

w Specify a minimum column width.

x After determining the width of all other columns, distribute the rest of the line
length among all columns having the x modifier.

z Do not use this cell for determining the width of this column.

|
Draw a single vertical line to the right of this cell.

|| Draw a double vertical line to the right of this cell.

If a modifier consists of decimal digits, it specifies a minimum spacing in units of n
between this column and the next column to the right. The default is 3. If there is a
vertical line, it is drawn inside the spacing.

Data
The data section follows the last Layout line. Each data line consists of one or more
data cells, delimited by tab characters.

If a data cell contains only the two bytes ‘\^’, the cell above spans to this row, as if
the layout specification of this cell were ^.

If a data cell contains only the single character ‘_’ or ‘=’, a single or double
horizontal line is drawn across the cell, joining its neighbours. If a data cell contains
only the two character sequence ‘\_’ or ‘\=’, a single or double horizontal line is drawn
inside the cell, not joining its neighbours. If a data line contains nothing but the
single character ‘_’ or ‘=’, a horizontal line across the whole table is inserted without
consuming a layout row.

In place of any data cell, a text block can be used. It starts with T{ at the end of a
physical input line. Input line breaks inside the text block neither end the text block
nor its data cell. It only ends if T} occurs at the beginning of a physical input line
and is followed by an end-of-cell indicator. If the T} is followed by the end of the
physical input line, the text block, the data cell, and the data line ends at this point.
If the T} is followed by the tab character, only the text block and the data cell end, but
the data line continues with the data cell following the tab character. If T} is followed
by any other character, it does not end the text block, which instead continues to the
following physical input line.

EXAMPLES

       String justification and font selection:

             .TS
             rb c  lb
             r  ci l.
             r    center    l
             ri   ce   le
             right     c    left
             .TE

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

       Some ports in OpenBSD 6.1 to show number alignment and line drawing:

             .TS
             box tab(:);
             r| l
             r  n.
             software:version
             _
             AFL:2.39b
             Mutt:1.8.0
             Ruby:1.8.7.374
             TeX Live:2015
             .TE

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

       Spans and skipping width calculations:

             .TS
             box tab(:);
             lz  s | rt
             lt| cb| ^
             ^ | rz  s.
             left:r
             l:center:
             :right
             .TE

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

       Text blocks, specifying spacings and specifying and equalizing column widths, putting
       lines into individual cells, and overriding allbox:

             .TS
             allbox tab(:);
             le le||7 lw10.
             The fourth line:_:line 1
             of this column:=:line 2
             determines:_:line 3
             the column width.:T{
             This text is too wide to fit into a column of width 17.
             T}:line 4
             T{
             No break here.
             T}::line 5
             .TE

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

             The -T man output mode does not support tbl(7) input.

       These examples were constructed to demonstrate many tbl features in a compact way.  In
       real manual pages, keep tables as simple as possible.  They usually look better, are less
       fragile, and are more portable.

COMPATIBILITY

       The mandoc(1) implementation of tbl doesn't support mdoc(7) and man(7) macros and eqn(7)
       equations inside tables.

HISTORY

       The tbl utility, a preprocessor for troff, was originally written by M.  E. Lesk at Bell
       Labs in 1975.  The GNU reimplementation of tbl, part of the groff package, was released in
       1990 by James Clark.  A standalone tbl implementation was written by Kristaps Dzonsons in
       2010.  This formed the basis of the implementation that first appeared in OpenBSD 4.9 as a
       part of the mandoc(1) utility.

AUTHORS

       This tbl reference was written by Kristaps Dzonsons <kristaps@bsd.lv> and
       Ingo Schwarze <schwarze@openbsd.org>.

BUGS

       In -T utf8 output mode, heavy lines are drawn instead of double lines.  This cannot be
       improved because the Unicode standard only provides an incomplete set of box drawing
       characters with double lines, whereas it provides a full set of box drawing characters
       with heavy lines.  It is unlikely this can be improved in the future because the box
       drawing characters are already marked in Unicode as characters intended only for backward
       compatibility with legacy systems, and their use is not encouraged.  So it seems unlikely
       that the missing ones might get added in the future.