format specification in text files
It is sometimes convenient to maintain text files on the UNIX
system with non-standard tabs,
(that is, tabs which 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 UNIX 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 followed immediately by a value.
The following parameters are recognized:
The d parameter takes no value.
Its presence indicates that the line containing the format specification
is to be deleted from the converted file.
If a format specification can be disguised as a comment,
it is not necessary to code the d parameter.
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.
The m parameter specifies a number of spaces to be
prepended to each line.
The value of margin must be an integer.
The s parameter specifies a maximum line size.
The value of size must be an integer.
Size checking is performed after the tabs have been expanded,
but before the margin is prepended.
The t parameter specifies
the tab settings for the file.
The value of tabs
must be one of the following:
a list of column numbers separated by commas,
indicating tabs set at the specified columns
a - (dash) followed by an integer n,
indicating tabs at intervals of n columns
a dash (-) followed by the name of a ``canned'' tab specification
Standard tabs are specified by t-8, or equivalently,
and so on. The canned tabs that are recognized are defined by the
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 performed.
If the first line of a file does not contain a format specification,
these defaults are assumed for the entire file.
The following is an example of a line containing a format specification:
/* <:t5,10,15 s72:> */
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003