tbl

Process a file containing tables through tbl and groff

$ groff -t [file.roff] | [less]

$ tbl [file.roff] | eqn | troff

$ cat [file.roff] | tbl

$ tbl --version

$ tbl -C [file.roff]

tbl [-Cv] [file...]

tbl is a preprocessor for the groff/troff document formatting system that formats tables. It translates table descriptions embedded between .TS (table start) and .TE (table end) macros into troff formatting commands.
Tables are defined with a format section specifying column alignment and a data section containing the content. Column classifiers include L (left), R (right), C (center), N (numeric alignment), and A (alphabetic). Modifiers like b (bold) and i (italic) can be applied to columns.
Region options control table appearance: box draws a border, center horizontally centers the table, expand stretches it to fill the line width, and tab(c) sets the column separator character.
tbl is typically invoked via groff -t rather than directly. When using multiple preprocessors, tbl should run before eqn (equations). The groff command handles ordering automatically.

-C

Enable AT&T compatibility mode; recognize .TS and .TE followed by any character

Print version information and exit

Display usage information and exit

$ .TS
box center;
c c c
l l n.
Header1 Header2 Value
Data1 Data2 100
Data3 Data4 200
.TE

c/l/r/n = center/left/right/numeric alignment

Lines ending with . separate format from data

Tab character separates columns by default

GNU tbl output requires GNU troff; it cannot be processed by AT&T troff. Complex tables with many spans or nested elements can be difficult to debug. The tab character is the default separator; use tab(;) to change it.

tbl was written by M.E. Lesk at Bell Labs and first documented in 1976 in the paper "TBL -- A Program to Format Tables." The GNU version was written by James Clark as part of groff. It extends the original with features like unlimited columns and improved compatibility.

groff(1), troff(1), eqn(1), pic(1), refer(1)