fspec(4)

NAME

     fspec - format specification in text files

DESCRIPTION

     It is sometimes convenient to maintain  text  files  on  the
     system  with  non-standard  tabs,  (tabs that are not set at
     every eighth column). Such files must generally be converted
     to  a standard format, frequently by replacing all tabs with
     the appropriate number of spaces, before they  can  be  pro-
     cessed  by system commands. A format specification occurring
     in the first line of a text file specifies how tabs  are  to
     be expanded in the remainder of the file.

     A format specification consists of a sequence of  parameters
     separated  by  blanks  and surrounded by the brackets <: and
     :>. Each parameter consists of a  keyletter,  possibly  fol-
     lowed  immediately  by a value. The following parameters are
     recognized:

     ttabs The t parameter specifies the  tab  settings  for  the
           file. The value of tabs must be one of the following:

              o  A list of column numbers  separated  by  commas,
                 indicating tabs set at the specified columns.

              o  A '-' followed  immediately  by  an  integer  n,
                 indicating tabs at intervals of n columns.

              o  A '-' followed by the name of a  ``canned''  tab
                 specification.
           Standard tabs are specified by t-8,  or  equivalently,
           t1,9,17,25,  etc.  The canned tabs that are recognized
           are defined by the tabs(1) command.

     ssize The s parameter specifies a  maximum  line  size.  The
           value  of  size  must  be an integer. Size checking is
           performed after tabs have been  expanded,  but  before
           the margin is prepended.

     mmargin
           The m parameter specifies a number  of  spaces  to  be
           prepended to each line. The value of margin must be an
           integer.

     d     The d parameter takes no value. Its presence indicates
           that  the  line containing the format specification is
           to be deleted from the converted file.

     e     The e parameter takes no value. Its presence indicates
           that  the  current  format  is  to  prevail only until
           another format specification  is  encountered  in  the
           file.

     Default values, which are assumed for  parameters  not  sup-
     plied,  are t-8 and m0. If the s parameter is not specified,
     no size checking is performed. If the first line of  a  file
     does  not contain a format specification, the above defaults
     are assumed for the entire file. The following is an example
     of a line containing a format specification:

          * <:t5,10,15 s72:> *

     If a format specification can be disguised as a comment,  it
     is not necessary to code the d parameter.

SEE ALSO

     ed(1), newform(1), tabs(1)