NAME

tabs — set terminal tabs

SYNOPSIS

DESCRIPTION

The tabs utility displays a series of characters that clear the hardware terminal tab settings then initialises tab stops at specified positions, and optionally adjusts the margin.

In the first synopsis form, the tab stops set depend on the command line options used, and may be one of the predefined formats or at regular intervals.

In the second synopsis form, tab stops are set at positions n1, n2, etc. If a position is preceded by a ‘+’, it is relative to the previous position set. No more than 20 positions may be specified.

If no tab stops are specified, the “standard” UNIX tab width of 8 is used.

The options are as follows:

-n

Set a tab stop every n columns. If n is 0, the tab stops are cleared but no new ones are set.

-a

Assembler format (columns 1, 10, 16, 36, 72).

-a2

Assembler format (columns 1, 10, 16, 40, 72).

-c

COBOL normal format (columns 1, 8, 12, 16, 20, 55)

-c2

COBOL compact format (columns 1, 6, 10, 14, 49)

-c3

COBOL compact format (columns 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58, 62, 67).

-f

FORTRAN format (columns 1, 7, 11, 15, 19, 23).

-p

PL/1 format (columns 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61).

-s

SNOBOL format (columns 1, 10, 55).

-u

Assembler format (columns 1, 12, 20, 44).

+m[n], +[n]

Set an n character left margin, or 10 if n is omitted.

-T type

Output escape sequence for the terminal type type.

ENVIRONMENT

The LANG, LC_ALL, LC_CTYPE and TERM environment variables affect the execution of tabs as described in environ(7).

The -T option overrides the setting of the TERM environment variable. If neither TERM nor the -T option are present, tabs will fail.

EXIT STATUS

The tabs utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

expand(1), stty(1), tput(1), unexpand(1), termcap(5)

STANDARDS

The tabs utility conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

HISTORY

/etc/tabs appeared in Version 1 AT&T UNIX which set tabs every 8 on Teletype model 37 and compatible printing terminals when printed. A tabs utility that worked on many terminals appeared in PWB UNIX. This implementation was introduced in FreeBSD 5.0.

BUGS

The current termcap(5) database does not define the ‘ML’ (set left soft margin) capability for any terminals.