TABS(1) User Commands TABS(1)

NAME

tabs - set tabs on a terminal

SYNOPSIS

tabs [-n | --file
[[-code] | -a | -a2 | -c | -c2 | -c3 | -f | -p | -s | -u]]
q!! [+m [n]] [-T type]


tabs [-T type] [+ m [n]] n1 [, n2 ,...]

DESCRIPTION

The tabs utility sets the tab stops on the user's terminal according
to a tab specification, after clearing any previous settings. The
user's terminal must have remotely settable hardware tabs.

OPTIONS

The following options are supported. If a given flag occurs more than
once, the last value given takes effect:

-T type
tabs needs to know the type of terminal in order to set
tabs and margins. type is a name listed in term(7). If
no -T flag is supplied, tabs uses the value of the
environment variable TERM. If the value of TERM is NULL
or TERM is not defined in the environment (see
environ(7)), tabs uses ansi+tabs as the terminal type to
provide a sequence that will work for many terminals.


+m[n]
The margin argument may be used for some terminals. It
causes all tabs to be moved over n columns by making
column n+1 the left margin. If +m is given without a
value of n, the value assumed is 10. For a TermiNet, the
first value in the tab list should be 1, or the margin
will move even further to the right. The normal
(leftmost) margin on most terminals is obtained by +m0.
The margin for most terminals is reset only when the +m
flag is given explicitly.

Tab Specification

Four types of tab specification are accepted. They are described
below: canned, repetitive (-n), arbitrary (n1,n2,...), and file
(-file).


If no tab specification is given, the default value is -8, that is,
UNIX system ``standard'' tabs. The lowest column number is 1. Note:
For tabs, column 1 always refers to the leftmost column on a
terminal, even one whose column markers begin at 0, for example, the
DASI 300, DASI 300s, and DASI 450.

Canned -code
Use one of the codes listed below to select a canned set of tabs. If
more than one code is specified, the last code option will be used.
The legal codes and their meanings are as follows:

-a
1,10,16,36,72 Assembler, IBM S/370, first format


-a2
1,10,16,40,72

Assembler, IBM S/370, second format


-c
1,8,12,16,20,55

COBOL, normal format


-c2
1,6,10,14,49

COBOL compact format (columns 1-6 omitted). Using this code,
the first typed character corresponds to card column 7, one
space gets you to column 8, and a tab reaches column 12. Files
using this tab setup should include a format specification as
follows (see fspec(5)):

<:t-c2 m6 s66 d:>


-c3
1,6,10,14,18,22,26,30,34,38,42,46,50,54,58,62,67

COBOL compact format (columns 1-6 omitted), with more tabs
than -c2. This is the recommended format for COBOL. The
appropriate format specification is (see fspec(5)):

<:t-c3 m6 s66 d:>


-f
1,7,11,15,19,23

FORTRAN


-p
1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61

PL/I


-s
1,10,55

SNOBOL


-u
1,12,20,44

UNIVAC 1100 Assembler


Repetitive
-n
A repetitive specification requests tabs at columns 1+n,
1+2*n, etc., where n is a single-digit decimal number. Of
particular importance is the value 8: this represents the UNIX
system ``standard'' tab setting, and is the most likely tab
setting to be found at a terminal. When -0 is used, the tab
stops are cleared and no new ones are set.


Arbitrary
See OPERANDS.

File
-file
If the name of a file is given, tabs reads the first line of
the file, searching for a format specification (see
fspec(5)). If it finds one there, it sets the tab stops
according to it, otherwise it sets them as -8. This type of
specification may be used to make sure that a tabbed file is
printed with correct tab settings, and would be used with
the pr command:

example% tabs - file; pr file


Tab and margin setting is performed via the standard output.

OPERANDS

The following operand is supported:

n1[,n2,...]
The arbitrary format consists of tab-stop
values separated by commas or spaces. The tab-
stop values must be positive decimal integers
in ascending order. Up to 40 numbers are
allowed. If any number (except the first one)
is preceded by a plus sign, it is taken as an
increment to be added to the previous value.
Thus, the formats 1,10,20,30, and 1,10,+10,+10
are considered identical.

EXAMPLES

Example 1: Using the tabs command

The following command is an example using -code ( canned
specification) to set tabs to the settings required by the IBM
assembler: columns 1, 10, 16, 36, 72:


example% tabs -a


The next command is an example of using -n (repetitive
specification), where n is 8, causes tabs to be set every eighth
position: 1+(1*8), 1+(2*8), ... which evaluate to columns 9, 17, ...:


example% tabs -8


This command uses n1,n2,... (arbitrary specification) to set tabs at
columns 1, 8, and 36:


example% tabs 1,8,36


The last command is an example of using -file (file specification) to
indicate that tabs should be set according to the first line of
$HOME/fspec.list/att4425 (see fspec(5)).


example% tabs -$HOME/fspec.list/att4425

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment
variables that affect the execution of tabs: LANG, LC_ALL, LC_CTYPE,
LC_MESSAGES, and NLSPATH.

TERM
Determine the terminal type. If this variable is unset or
null, and if the -T option is not specified, terminal type
ansi+tabs will be used.

EXIT STATUS

The following exit values are returned:

0
Successful completion.


>0
An error occurred.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+

SEE ALSO

expand(1), newform(1), pr(1), stty(1), tput(1), fspec(5),
terminfo(5), attributes(7), environ(7), standards(7), term(7)

NOTES

There is no consistency among different terminals regarding ways of
clearing tabs and setting the left margin.


tabs clears only 20 tabs (on terminals requiring a long sequence),
but is willing to set 64.


The tabspec used with the tabs command is different from the one used
with the newform command. For example, tabs -8 sets every eighth
position; whereas newform -i-8 indicates that tabs are set every
eighth position.

February 1, 1995 TABS(1)