[unix-history] / usr / doc / usd / 25.trofftut / tt05

.\"	@(#)tt05	6.1 (Berkeley) 5/23/86
.\"
.NH
Tabs
.PP
Tabs
(the \s8ASCII\s0 `horizontal tab' character)
can be used to produce output in columns,
or to set the horizontal position of output.
Typically
tabs are used only in unfilled text.
Tab stops are set by default every half inch from the
current indent,
but
can be changed by the
.BD .ta
command.
To set stops every inch, for example,
.P1
^ta 1i 2i 3i 4i 5i 6i
.P2
.PP
Unfortunately the stops are left-justified only
(as on a typewriter),
so lining up columns of right-justified numbers can be painful.
If you have many numbers,
or if you need more complicated table layout,
.ul
don't
use
.UL troff 
directly;
use the
.UL tbl
program described in [3].
.PP
For a handful of numeric columns, you can do it this way:
Precede every number by enough blanks to make it line up
when typed.
.P1
^nf
^ta 1i 2i 3i
\0\01\0\fItab\fR\0\0\02\0\fItab\fR\0\0\03
\040\0\fItab\fR\0\050\0\fItab\fR\0\060
700\0\fItab\fR\0800\0\fItab\fR\0900
^fi
.P2
Then change each leading blank into the string
.BD \e0 .
This is a character that does not print, but that has
the same width as a digit.
When printed, this will produce
.P1
.ta 1i 2i 3i
\0\01	\0\02	\0\03
\040	\050	\060
700	800	900
.P2
.PP
It is also possible to fill up tabbed-over space with
some character other than blanks by setting the `tab replacement character'
with the
.BD .tc
command:
.P1
^ta 1.5i 2.5i
^tc \e(ru	(\e(ru is "\(ru")
Name \fItab\fR Age \fItab\fR 
.P2
produces
.P1 3
.ta 1.5i 2.5i
.tc \(ru
Name	 Age 	
.tc
.P2
To reset the tab replacement character to a blank, use
.BD .tc
with no argument.
(Lines can also be drawn with the
.BD \el
command, described in Section 6.)
.PP
.UL troff
also provides a very general mechanism called `fields'
for setting up complicated columns.
(This is used by
.UL tbl ).
We will not go into it in this paper.
Commit	Line	Data
95f51977	1	.\" @(#)tt05 6.1 (Berkeley) 5/23/86
aa4faf0e KD	2	.\"
	3	.NH
	4	Tabs
	5	.PP
	6	Tabs
	7	(the \s8ASCII\s0 `horizontal tab' character)
	8	can be used to produce output in columns,
	9	or to set the horizontal position of output.
	10	Typically
	11	tabs are used only in unfilled text.
	12	Tab stops are set by default every half inch from the
	13	current indent,
	14	but
	15	can be changed by the
	16	.BD .ta
	17	command.
	18	To set stops every inch, for example,
	19	.P1
	20	^ta 1i 2i 3i 4i 5i 6i
	21	.P2
	22	.PP
	23	Unfortunately the stops are left-justified only
	24	(as on a typewriter),
	25	so lining up columns of right-justified numbers can be painful.
	26	If you have many numbers,
	27	or if you need more complicated table layout,
	28	.ul
	29	don't
	30	use
	31	.UL troff
	32	directly;
	33	use the
	34	.UL tbl
	35	program described in [3].
	36	.PP
	37	For a handful of numeric columns, you can do it this way:
	38	Precede every number by enough blanks to make it line up
	39	when typed.
	40	.P1
	41	^nf
	42	^ta 1i 2i 3i
	43	\0\01\0\fItab\fR\0\0\02\0\fItab\fR\0\0\03
	44	\040\0\fItab\fR\0\050\0\fItab\fR\0\060
	45	700\0\fItab\fR\0800\0\fItab\fR\0900
	46	^fi
	47	.P2
	48	Then change each leading blank into the string
	49	.BD \e0 .
	50	This is a character that does not print, but that has
	51	the same width as a digit.
	52	When printed, this will produce
	53	.P1
	54	.ta 1i 2i 3i
	55	\0\01 \0\02 \0\03
	56	\040 \050 \060
	57	700 800 900
	58	.P2
	59	.PP
	60	It is also possible to fill up tabbed-over space with
	61	some character other than blanks by setting the `tab replacement character'
	62	with the
	63	.BD .tc
	64	command:
	65	.P1
66	^ta 1.5i 2.5i
67	^tc \e(ru (\e(ru is "\(ru")
68	Name \fItab\fR Age \fItab\fR
69	.P2
70	produces
71	.P1 3
72	.ta 1.5i 2.5i
73	.tc \(ru
74	Name Age
75	.tc
76	.P2
77	To reset the tab replacement character to a blank, use
78	.BD .tc
79	with no argument.
80	(Lines can also be drawn with the
81	.BD \el
82	command, described in Section 6.)
83	.PP
84	.UL troff
85	also provides a very general mechanism called `fields'
86	for setting up complicated columns.
87	(This is used by
88	.UL tbl ).
89	We will not go into it in this paper.