FSPEC(4)FSPEC(4)NAMEfspec - format specification in text files
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 processed 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 con‐
sists of a keyletter, possibly followed immediately by a value. The
following parameters are recognized:
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, indi‐
cating tabs at intervals of n columns.
o A '−' followed by the name of a ``canned'' tab
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.
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.
The m parameter specifies a number of spaces to be prepended
to each line. The value of margin must be an integer.
The d parameter takes no value. Its presence indicates that
the line containing the format specification is to be
deleted from the converted file.
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 supplied, are t−8
and m0. If the s parameter is not specified, no size checking is per‐
formed. If the first line of a file does not contain a format specifi‐
cation, the above defaults are assumed for the entire file. The follow‐
ing 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 nec‐
essary to code the d parameter.
SEE ALSOed(1), newform(1), tabs(1)
Jul 3, 1990 FSPEC(4)