TBL(7)

NAME
tbl - tbl language reference for mandoc

DESCRIPTION
The tbl language is a table-formatting language. It is used within mdoc(7) and man(7) UNIX manual pages. This manual describes the subset of the tbl language accepted by the mandoc(1) utility.

Tables within mdoc(7) or man(7) are enclosed by the ‘TS’ and ‘TE’ macro tags, whose precise syntax is documented in roff(7). Tables consist of a series of options on a single line, followed by the table layout, followed by data.

For example, the following creates a boxed table with digits centered in the cells.

    .TS
    tab(:) box;
    c5 c5 c5.
    1:2:3
    4:5:6
    .TE

When formatted, the following output is produced:
1 | 2 | 3
4 | 5 | 6

TABLE STRUCTURE
Tables are enclosed by the ‘TS’ and ‘TE’ roff(7) macros. A table consists of an optional single line of table Options terminated by a semicolon, followed by one or more lines of Layout specifications terminated by a period, then Data. All input must be 7-bit ASCII. Example:

    .TS
    box tab(:);
    c | c
    | c | c.
    1:2
    3:4
    .TE

Table data is pre-processed, that is, data rows are parsed then inserted into the underlying stream of input data. This allows data rows to be interspersed by arbitrary roff(7), mdoc(7), and man(7) macros such as

    .TS
    tab(:);
    c c c.
    1:2:3
    .Ao
    3:2:1
    .Ac
    .TE

in the case of mdoc(7) or

    .TS
    tab(:);
    c c c.
    .ds ab 2
    1:\*(ab:3
    .I
    3:2:1
    .TE

in the case of man(7).

  Options
The first line of a table may contain options separated by spaces, tabs, or commas and terminated by a semicolon. If the first line does not have a terminating semicolon, it is assumed that no options are specified and instead a Layout is processed. Some options require arguments enclosed by parentheses. The following case-insensitive options are available:

allbox
    Draw a single-line box around each table cell. Currently treated as a synonym for box.

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 and currently ignored.

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 tab character is used.

  Layout
The table layout follows Options or a ‘T&’ macro invocation. Layout specifies how data rows are displayed on output. Each layout line corresponds to a line of data; the last layout line applies to all remaining data lines. Layout lines may also be separated by a comma. Each layout cell consists of one of the following case-insensitive keys:

c   Center a literal string within its column.

r   Right-justify a literal string within its column.

l   Left-justify a literal string within its column.

n   Justify a number around its last decimal point. If the decimal point is not found on the number, it's assumed to trail the number.

s   Horizontally span columns from the last non-s data cell. It is an error if spanning columns follow a - or | cell, or come first. This option is not supported by mandoc(1).

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

^   Vertically span rows from the last non-^ data cell. It is an error to invoke a vertical span on the first layout row. Unlike a horizontal spanner, you must specify an empty cell (if it not empty, the data is discarded) in the corresponding data cell.

-   Replace the data cell (its contents will be lost) with a single horizontal line. This may also be invoked with _.

=   Replace the data cell (its contents will be lost) with a double horizontal line.

|   Emit a vertical bar instead of data.

||  Emit a double-vertical bar instead of data.

Keys may be followed by a set of modifiers. A modifier is either a modifier key or a natural number for specifying the minimum width of a column. The following case-insensitive modifier keys are available:

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

d   Move cell content down to the last cell of a 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 character selects the font to use for this column. See the roff(7) manual for supported one-character font names.

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

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 cell content in the vertical span, leave it at the top. Currently ignored.

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

w   Specify minimum column width. Currently ignored.

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.

For example, the following layout specifies a center-justified column of minimum width 10, followed by vertical bar, followed by a left-justified column of minimum width 10, another vertical bar, then a column using bold font justified about the decimal point in numbers:

    c10 | l10 | nfB

  Data
The data section follows the last layout row. By default, cells in a data section are delimited by a tab. This behaviour may be changed with the tab option. If _ or = is specified, a single or double line, respectively, is drawn across the data field. If \- or \= is specified, a line is drawn within the data field (i.e. terminating within the cell and not draw to the border). If the last cell of a line is T{, all subsequent lines are included as part of the cell until T} is specified as its own data cell. It may then be followed by a tab (or as designated by tab) or an end-of-line to terminate the row.

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

SEE ALSO
mandoc(1), man(7), mandoc_char(7), mdoc(7), roff(7) M. E. Lesk, Tbl—A Program to Format Tables, June 11, 1976.

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 is part of the mandoc(1) utility.

AUTHORS
This tbl reference was written by Kristaps Dzonsons <kristaps@bsd.lv>.