Affects the characteristics of MVS text files opened with the default
attributes. Issuing the following command causes text files opened
with the default characteristics to be opened with a record format
of FIXED and a logical record length of 254 in accordance with the
ANSI standard for C.
setenv("_EDC_ANSI_OPEN_DEFAULT","Y",1);
When this environment variable is not specified and a text file
is created without its record format or LRECL defined, then the default
is a variable record format.