tbl
format tables for troff
see also :
groff - troff
Synopsis
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examples
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description
This manual
page describes the GNU version of tbl, which is part
of the groff document formatting system. tbl compiles
descriptions of tables embedded within troff input
files into commands that are understood by troff.
Normally, it should be invoked using the -t
option of groff. It is highly compatible with Unix
tbl. The output generated by GNU tbl cannot be
processed with Unix troff; it must be processed with
GNU troff. If no files are given on the command line
or a filename of - is given, the standard input
is read.
options
-C
Enable compatibility mode to
recognize .TS and .TE even when followed by a
character other than space or newline. Leader characters
(\a) are handled as interpreted.
-v
Print the version number.
gnu tbl enhancements
There is no limit on the number of columns in a table, nor any
limit on the number of text blocks. All the lines of a table are
considered in deciding column widths, not just the first 200.
Table continuation (.T&) lines are not restricted to the
first 200 lines.
Numeric and alphabetic items may appear in the same column.
Numeric and alphabetic items may span horizontally.
tbl uses register, string, macro and diversion names
beginning with the digit 3. When using tbl you
should avoid using any names beginning with a 3.
gnu tbl within macros
Since tbl defines its own macros (right before each table)
it is necessary to use an ’end-of-macro’ macro. Additionally, the
escape character has to be switched off. Here an example.
.eo
.de ATABLE ..
.TS
allbox tab(;);
cl.
\$1;\$2
.TE
.ec
.ATABLE A table
.ATABLE Another table
.ATABLE And "another one"
Note, however, that not all features of tbl can be wrapped
into a macro because tbl sees the input earlier than
troff. For example, number formatting with vertically
aligned decimal points fails if those numbers are passed on as
macro parameters because decimal point alignment is handled by
tbl itself: It only sees ’\$1’, ’\$2’, etc., and therefore
can’t recognize the decimal point.
interaction with eqn
tbl(1) should always be called before eqn(1)
(groff(1) automatically takes care of the correct order of
preprocessors).
It is not advisable to use the hash character (#) as a delimiter
for in-line equations in eqn(1) since tbl uses a
macro called .T#, causing a clash.
reference
Lesk, M.E.: "TBL – A Program to Format Tables". For copyright
reasons it cannot be included in the groff distribution, but
copies can be found with a title search on the World Wide Web.
usage
tbl expects to find table descriptions wrapped in the
.TS (table start) and .TE (table end) macros.
Global options
The line immediately following the .TS macro may contain
any of the following global options (ignoring the case of
characters – Unix tbl only accepts options with all characters
lowercase or all characters uppercase), separated by spaces,
tabs, or commas:
allbox
Enclose each item of the table in a box.
box
Enclose the table in a box.
center
Center the table (default is left-justified). The alternative
keyword name centre is also recognized (this is a GNU tbl
extension).
decimalpoint(c)
Set the character to be recognized as the decimal point in
numeric columns (GNU tbl only).
delim(xy)
Use x and y as start and end delimiters for
eqn(1).
doublebox
Enclose the table in a double box.
doubleframe
Same as doublebox (GNU tbl only).
expand
Make the table as wide as the current line length (providing a
column separation factor). Ignored if one or more ’x’ column
specifiers are used (see below).
In case the sum of the column widths is larger than the current
line length, the column separation factor is set to zero; such
tables extend into the right margin, and there is no column
separation at all.
frame
Same as box (GNU tbl only).
linesize(n)
Set lines or rules (e.g. from box) in n-point type.
nokeep
Don’t use diversions to prevent page breaks (GNU tbl only).
Normally tbl attempts to prevent undesirable breaks in
boxed tables by using diversions. This can sometimes interact
badly with macro packages’ own use of diversions, when footnotes,
for example, are used.
nospaces
Ignore leading and trailing spaces in data items (GNU tbl only).
nowarn
Turn off warnings related to tables exceeding the current line
width (GNU tbl only).
tab(x)
Use the character x instead of a tab to separate items in
a line of input data.
The global options must end with a semicolon. There might be
whitespace between an option and its argument in parentheses.
Table format specification
After global options come lines describing the format of each
line of the table. Each such format line describes one line of
the table itself, except that the last format line (which you
must end with a period) describes all remaining lines of the
table. A single-key character describes each column of each line
of the table. Key characters can be separated by spaces or tabs.
You may run format specifications for multiple lines together on
the same line by separating them with commas.
You may follow each key character with specifiers that determine
the font and point size of the corresponding item, that determine
column width, inter-column spacing, etc.
The longest format line defines the number of columns in the
table; missing format descriptors at the end of format lines are
assumed to be L. Extra columns in the data (which
have no corresponding format entry) are ignored.
The available key characters are:
a,A
Center longest line in this column and then left-justifies all
other lines in this column with respect to that centered line.
The idea is to use such alphabetic subcolumns (hence the name of
the key character) in combination with L; they are called
subcolumns because A items are indented by 1n
relative to L entries. Example:
.TS
tab(;);
ln,an.
item one;1
subitem two;2
subitem three;3
.T&
ln,an.
item eleven;11
subitem twentytwo;22
subitem thirtythree;33
.TE
Result:
c,C
Center item within the column.
l,L
Left-justify item within the column.
n,N
Numerically justify item in the column: Units positions of
numbers are aligned vertically. If there is one or more dots
adjacent to a digit, use the rightmost one for vertical
alignment. If there is no dot, use the rightmost digit for
vertical alignment; otherwise, center the item within the column.
Alignment can be forced to a certain position using ’\&’; if
there is one or more instances of this special (non-printing)
character present within the data, use the leftmost one for
alignment. Example:
.TS
n.
1
1.5
1.5.3
abcde
a\&bcde
.TE
Result:
If numerical entries are combined with L or
R entries – this can happen if the table format is
changed with .T& –, center the widest number (of
the data entered under the N specifier regime)
relative to the widest L or R entry,
preserving the alignment of all numerical entries. Contrary to
A type entries, there is no extra indentation.
Using equations (to be processed with eqn) within columns
which use the N specifier is problematic in most
cases due to tbl’s algorithm for finding the vertical
alignment, as described above. Using the global delim
option, however, it is possible to make tbl ignore the
data within eqn delimiters for that purpose.
r,R
Right-justify item within the column.
s,S
Span previous item on the left into this column. Not allowed for
the first column.
^
Span down entry from previous row in this column. Not allowed for
the first row.
_,-
Replace this entry with a horizontal line. Note that ’_’ and ’-’
can be used for table fields only, not for column separator
lines.
=
Replace this entry with a double horizontal line. Note that ’=’
can be used for table fields only, not for column separator
lines.
|
The corresponding column becomes a vertical rule (if two of these
are adjacent, a double vertical rule).
A vertical bar to the left of the first key letter or to the
right of the last one produces a line at the edge of the table.
To change the data format within a table, use the .T&
command (at the start of a line). It is followed by format and
data lines (but no global options) similar to the .TS
request.
Column specifiers
Here are the specifiers that can appear in suffixes to column key
letters (in any order):
b,B
Short form of fB (make affected entries bold).
d,D
Start an item that vertically spans rows, using the ’^’ column
specifier or ’\^’ data item, at the bottom of its range rather
than vertically centering it (GNU tbl only). Example:
.TS
tab(;) allbox;
l l
l ld
r ^
l rd.
0000;foobar
T{
1111
.br
2222
T};foo
r;
T{
3333
.br
4444
T};bar
.TE
Result:
e,E
Make equally-spaced columns. All columns marked with this
specifier get the same width; this happens after the affected
column widths have been computed (this means that the largest
width value rules).
f,F
Either of these specifiers may be followed by a font name (either
one or two characters long), font number (a single digit), or
long name in parentheses (the last form is a GNU tbl extension).
A one-letter font name must be separated by one or more blanks
from whatever follows.
i,I
Short form of fI (make affected entries italic).
m,M
This is a GNU tbl extension. Either of these specifiers may be
followed by a macro name (either one or two characters long), or
long name in parentheses. A one-letter macro name must be
separated by one or more blanks from whatever follows. The macro
which name can be specified here must be defined before creating
the table. It is called just before the table’s cell text is
output. As implemented currently, this macro is only called if
block input is used, that is, text between ’T{’ and ’T}’. The
macro should contain only simple troff requests to change
the text block formatting, like text adjustment, hyphenation,
size, or font. The macro is called after other cell
modifications like b, f or v are output.
Thus the macro can overwrite other modification specifiers.
p,P
Followed by a number, this does a point size change for the
affected fields. If signed, the current point size is incremented
or decremented (using a signed number instead of a signed digit
is a GNU tbl extension). A point size specifier followed by a
column separation number must be separated by one or more blanks.
t,T
Start an item vertically spanning rows at the top of its range
rather than vertically centering it.
u,U
Move the corresponding column up one half-line.
v,V
Followed by a number, this indicates the vertical line spacing to
be used in a multi-line table entry. If signed, the current
vertical line spacing is incremented or decremented (using a
signed number instead of a signed digit is a GNU tbl extension).
A vertical line spacing specifier followed by a column separation
number must be separated by one or more blanks. No effect if the
corresponding table entry isn’t a text block.
w,W
Minimum column width value. Must be followed either by a
troff(1) width expression in parentheses or a unitless
integer. If no unit is given, en units are used. Also used as the
default line length for included text blocks. If used multiple
times to specify the width for a particular column, the last
entry takes effect.
x,X
An expanded column. After computing all column widths without an
x specifier, use the remaining line width for this
column. If there is more than one expanded column, distribute the
remaining horizontal space evenly among the affected columns
(this is a GNU extension). This feature has the same effect as
specifying a minimum column width.
z,Z
Ignore the corresponding column for width-calculation purposes,
this is, don’t use the fields but only the specifiers of this
column to compute its width.
A number suffix on a key character is interpreted as a column
separation in en units (multiplied in proportion if the
expand option is on – in case of overfull tables this
might be zero). Default separation is 3n.
The column specifier x is mutually exclusive with
e and w (but e is not mutually
exclusive with w); if specified multiple times for a
particular column, the last entry takes effect:
x unsets both e and w, while
either e or w overrides x.
Table data
The format lines are followed by lines containing the actual data
for the table, followed finally by .TE. Within such data
lines, items are normally separated by tab characters (or the
character specified with the tab option). Long input lines
can be broken across multiple lines if the last character on the
line is ’\’ (which vanishes after concatenation).
Note that tbl computes the column widths line by line,
applying \w on each entry which isn’t a text block. As a
consequence, constructions like
.TS
c,l.
\s[20]MM
MMMM
.TE
fail; you must either say
.TS
cp20,lp20.
MM
MMMM
.TE
or
.TS
c,l.
\s[20]MM
\s[20]MMMM
.TE
A dot starting a line, followed by anything but a digit is
handled as a troff command, passed through without changes. The
table position is unchanged in this case.
If a data line consists of only ’_’ or ’=’, a single or double
line, respectively, is drawn across the table at that point; if a
single item in a data line consists of only ’_’ or ’=’, then that
item is replaced by a single or double line, joining its
neighbours. If a data item consists only of ’\_’ or ’\=’, a
single or double line, respectively, is drawn across the field at
that point which does not join its neighbours.
A data item consisting only of ’\Rx’ (’x’ any character) is
replaced by repetitions of character ’x’ as wide as the column
(not joining its neighbours).
A data item consisting only of ’\^’ indicates that the field
immediately above spans downward over this row.
Text blocks
A text block can be used to enter data as a single entry which
would be too long as a simple string between tabs. It is started
with ’T{’ and closed with ’T}’. The former must end a line, and
the latter must start a line, probably followed by other data
columns (separated with tabs or the character given with the
tab global option).
By default, the text block is formatted with the settings which
were active before entering the table, possibly overridden by the
m, v, and w tbl specifiers. For example, to
make all text blocks ragged-right, insert .na right before
the starting .TS (and .ad after the table).
If either ’w’ or ’x’ specifiers are not given for all
columns of a text block span, the default length of the text
block (to be more precise, the line length used to process the
text block diversion) is computed as L×C/(N+1), where ’L’ is the
current line length, ’C’ the number of columns spanned by the
text block, and ’N’ the total number of columns in the table.
Note, however, that the actual diversion width as returned in
register \n[dl] is used eventually as the text block
width. If necessary, you can also control the text block width
with a direct insertion of a .ll request right after ’T{’.
Miscellaneous
The number register \n[TW] holds the table width; it can’t
be used within the table itself but is defined right before
calling .TE so that this macro can make use of it.
tbl also defines a macro .T# which produces the
bottom and side lines of a boxed table. While tbl does
call this macro itself at the end of the table, it can be used by
macro packages to create boxes for multi-page tables by calling
it within the page footer. An example of this is shown by the
-ms macros which provide this functionality if a table
starts with .TS H instead of the standard call to the
.TS macro.
bugs
You should use
.TS H/.TH in conjunction with a
supporting macro package for all multi-page boxed
tables. If there is no header that you wish to appear at the
top of each page of the table, place the .TH line
immediately after the format section. Do not enclose a
multi-page table within keep/release macros, or divert it in
any other way.
A text block
within a table must be able to fit on one page.
The bp
request cannot be used to force a page-break in a multi-page
table. Instead, define BP as follows
.de BP
. ie ’\\n(.z’’ .bp \\$1
. el \!.BP \\$1
..
and use
BP instead of bp.
Using \a
directly in a table to get leaders does not work (except in
compatibility mode). This is correct behaviour: \a is an
uninterpreted leader. To get leaders use a real
leader, either by using a control A or like this:
.ds a \a
.TS
tab(;);
lw(1i) l.
A\*a;B
.TE
A leading
and/or trailing ’|’ in a format line, such
as
|l r|.
gives output
which has a 1n space between the resulting bordering
vertical rule and the content of the adjacent column, as
in
.TS
tab(#);
|l r|.
left column#right column
.TE
If it is
desired to have zero space (so that the rule touches the
content), this can be achieved by introducing extra
“dummy” columns, with no content and zero
separation, before and/or after, as in
.TS
tab(#);
r0|l r0|l.
#left column#right column#
.TE
The resulting
“dummy” columns are invisible and have zero
width; note that such columns usually don’t work with
TTY devices.
see also
groff ,
troff