TABS(1) RISC/os Reference Manual TABS(1)
NAME
tabs - set tabs on a terminal
SYNOPSIS
tabs [tabspec] [-Ttype] [+mn]
DESCRIPTION
tabs sets the tab stops on the user's terminal according to
the tab specification tabspec, after clearing any previous
settings. The user's terminal must have remotely settable
hardware tabs.
tabspec Four types of tab specification are accepted for
tabspec. They are described below: canned (-code),
repetitive (-n), arbitrary (n1,n2,...), and file
(--file). If no tabspec is given, the default value
is -8, i.e., UNIX system ``standard'' tabs. The
lowest column number is 1. Note that for tabs,
column 1 always refers to the leftmost column on a
terminal, even one whose column markers begin at 0,
e.g., the DASI 300, DASI 300s, and DASI 450.
-code Use one of the codes listed below to select a canned
set of tabs. 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(4)):
<: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 recom-
mended format for COBOL. The appropriate
format specification is [see fspec(4)]:
<: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
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TABS(1) RISC/os Reference Manual TABS(1)
-u 1,12,20,44
UNIVAC 1100 Assembler
-n A repetitive specification requests tabs at columns
1+n, 1+2*n, etc. Of particular importance is the
value 8: this represents the UNIX system ``stan-
dard'' tab setting, and is the most likely tab set-
ting to be found at a terminal. Another special
case is the value 0, implying no tabs at all.
n1,n2,...
The arbitrary format permits the user to type any
chosen set of numbers, separated by commas, 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 identi-
cal.
--file If the name of a file is given, tabs reads the first
line of the file, searching for a format specifica-
tion [see fspec(4)]. 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:
tabs -- file; pr file
Any of the following also may be used; if a given flag
occurs more than once, the last value given takes effect:
-Ttype tabs usually needs to know the type of terminal in
order to set tabs and always needs to know the type
to set margins. type is a name listed in term(5).
If no -T flag is supplied, tabs uses the value of
the environment variable TERM. If TERM is not
defined in the environment [see environ(5)], tabs
tries a sequence that will work for many terminals.
+mn 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 termi-
nals is obtained by +m0. The margin for most termi-
nals is reset only when the +m flag is given expli-
citly.
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TABS(1) RISC/os Reference Manual TABS(1)
Tab and margin setting is performed via the standard output.
EXAMPLES
tabs -a example using -code (canned specification) to
set tabs to the settings required by the IBM
assembler: columns 1, 10, 16, 36, 72.
tabs -8 example of using -n (repetitive specifica-
tion), where n is 8, causes tabs to be set
every eighth position:
1+(1*8), 1+(2*8), ... which evaluates to
columns 9, 17, ...
tabs 1,8,36 example of using n1,n2,... (arbitrary
specification) to set tabs at columns 1, 8,
and 36.
tabs --$HOME/fspec.list/att4425
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(4)].
DIAGNOSTICS
illegal tabs when arbitrary tabs are ordered
incorrectly
illegal increment when a zero or missing increment is
found in an arbitrary specification
unknown tab code when a canned code cannot be found
can't open if --file option used, and file can't be
opened
file indirection if --file option used and the specifica-
tion in that file points to yet another
file. Indirection of this form is not
permitted
SEE ALSO
newform(1), pr(1), tput(1).
fspec(4), terminfo(4), environ(5), term(5) in the System
Administrator's Reference Manual.
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.
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