tabs(1)								      tabs(1)

  tabs - Sets tab stops on terminals


  tabs [tab_spec] [+mnumber] [-Tterminal]

  The tabs command clears up to 20 previous tabs and sets up to 40 tabs on
  the terminal according to the supplied tab_spec.


  If the same flag occurs more than once, only the last one takes effect.

  -n  Specifies repetitive tab stops separated by a uniform number of column
      positions, n, where n is a single-digit number. The default usage of
      tabs with no arguments is equivalent to tabs -8. If you use -0, the tab
      stops are cleared and no new ones are set.

      Identifies the terminal so that tabs can set tabs and margins
      correctly.  The terminal argument is one of the conventional terminal
      names supported by your system.

      If the terminal you specify is not known to the system, tabs tries a
      general value that works for most terminals.

      If you do not provide a -T flag, tabs uses the TERM shell variable.

      Moves all tabs to the right number columns, and makes column number+1
      the left margin.	(Note that columns = bytes.)

       If m is given without a value, 10 is assumed.  The leftmost margin on
      most terminals is defined by m0.


  The tab_spec argument can be a flag representing one of the pre-set tab
  specifications listed below.	It can also be an alternative specification
  using either column numbers or the name of an existing file, as described
  below.  If you do not specify a tab_spec, the default value is -8.

  The available flags cover formats required by most structured programming

  When you use the tabs command, always consider the leftmost column number
  to be 1, even if your terminal refers to it as 0 (zero).  Tab-stop position
  n means that tabbing to position n causes the next character output to be
  in the n+1th column position on that line.

  Tab Specification Flags

  -a  Sets the tabs to 1, 10, 16, 36, and 72.

  -a2 Sets the tabs to 1, 10, 16, 40, and 72.

  -c  Sets the tabs to 1, 8, 12, 16, 20, and 55 (COBOL normal format)

  -c2 Sets the tabs to 1, 6, 10, 14, and 49 (COBOL compact format, columns 1
      to 6 omitted).  With this code, the first column position corresponds
      to card column 7.	 One space gets you to column 8, and a tab reaches
      column 12.  Files using this code must include the following format
	   <:t-c2  m6  s66  d:>

      See Format Specifications later in this manpage.

  -c3 Sets the tabs to 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54,
      58, 62, and 67 (COBOL compact format with more tabs than -c2).  This is
      the recommended format for COBOL.	 Files using this code must include
      the following format specification:
	   <:t-c3  m6  s66  d:>

  -f  Sets the tabs to 1, 7, 11, 15, 19, and 23 (FORTRAN).

  -p  Sets the tabs to 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53,
      57, and 61 (PL/I).

  -s  Sets the tabs to 1, 10, and 55 (SNOBOL).

  -u  Sets the tabs to 1, 12, 20, and 44.

  In addition to the preset formats, three other types of tab_specs are

      Sets regularly repeating tabs at every number column.  The standard tab
      setting is -8 and is the setting required for use with the nroff -h
      flag.  Another special case is -0, which implies no tabs at all.

  number[,number] ...
      Sets tabs at the named column numbers (a list in ascending order,
      separated by commas).  You can specify up to 40 numbers.	If any number
      except the first has a plus sign prefix, the prefixed number is added
      to the previous number for the next setting.  Thus, the tab lists
      1,10,20,30 and 1,10,+10,+10 provide the same tab settings.

  Format Specifications

       A format specification consists of a sequence of arguments separated
       by blanks and enclosed in brackets and colons: <: :>.  Each argument
       consists of a keyletter and an optional value which immediately fol-
       lows it.	 The following arguments can be used:

      Specifies tab settings.  tabs can be: a list of column numbers
      separated by commas, indicating tab stops at the specified columns; a -
      (dash) followed by a number n, specifying tabs stops every n columns;
      or a - (dash) followed by a pre-set tab specification, for example a2
      (see DESCRIPTION).

      Specifies a maximum line size, or length.	 The size specification must
      be an integer.  (size is checked after tabs have been expanded but
      before the margin is prepended.)

      Specifies a number of spaces to be inserted at the beginning of each
      line.  The margin specification must be an integer.

  d   Indicates that the line containing the format specification is to be
      deleted from the converted file.

  e   Indicates that the current format should prevail only until another
      format specification is encountered in the file.

  Default values of t-8 and m0 are assumed if t and m arguments are not
  included in the specification; if s is not included, line size is not
  checked.  If the first line of a file does not contain a format specifica-
  tion, these defaults are assumed for the entire file.

  If a format specification can be disguised as a comment, for example *
  <:t5,10,15 s75 m5:> *, you do not need to include the d keyletter.


  To set tabs every four spaces, enter:

       tabs -4


  Commands: nroff(1), tset(1).