


This variable specifies a format for naming the data segments of a Vision 4
file. The configuration variable used is constructed from the file's base name
and extension, with all letters converted to upper case and all non-alphanumeric
characters converted to underscores, followed by the "_DATA_FMT" string.
Suppose that the regular name of your COBOL file is "/usr1/gl.dat". The
variable you would use to set the data segment naming format for this file is
GL_DAT_DATA_FMT.
The variable must be set equal to a pattern that shows how to create the
segment names. The pattern shows how to form the base name and extension for each
segment. Part of this pattern is a special escape sequence (such as %d) that
specifies how the segment number should be represented. Choices include %d
(decimal segment numbers), %x (lowercase hexadecimal numbers), %X (uppercase
hexadecimal numbers), and %o (octal numbers).
For example, setting the variable GL_DAT_DATA_FMT=gl%d.dat would result in
data segments named /usr1/gl.dat (remember that the first data segment is not
affected), /usr1/gl1.dat, /usr1/gl2.dat, and so forth.
Escape Sequence Definitions:
The %d in the value of the filename_DATA_FMT above is a printf-style escape sequence. Most reference books on
the C language contain an in-depth explanation of these escape sequences, and
UNIX systems typically have a man page ("man printf") that explains them in
detail. Here are the basics:
"%d" expands into the decimal representation of the segment number.
"%x" expands into the hexadecimal representation (with lower case a-f) of the
segment number.
"%X" expands into the hexadecimal representation (with upper case A-F) of the
segment number.
"%o" expands into the octal representation of the segment number.
You can add leading zeros to the number (to keep all the file names the same
length) by placing a zero and a length digit between the percent sign and the
following character. "%02d" would result in "00", "01", "02", and so forth, when
expanded.
To embed a literal "%" in the file name, use "%%".
The escape sequence can be positioned anywhere in the file name, including the
extension.