


This variable specifies a format for naming the index segments of a Vision
Version 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 "_INDEX_FMT"
string.
Suppose that the regular name of your COBOL file is "/usr1/gl.dat". The
variable you would use to set the format for naming the file's index segments is
GL_DAT_INDEX_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 how to form the
extension for each segment. Part of this pattern is a special character (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_INDEX_FMT=gl%d.idx would result in
index segments named /usr1/gl0.idx, /usr1/gl1.idx, /usr1/gl2.idx, and so forth.
Escape Sequence Definitions:
The %d in the value of the filename_INDEX_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 he
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.