XL Fortran Enterprise Edition for AIX : User's Guide - IBM

Related Information: See “Environment Variables for National Language Support”
on page 13.
The C library routine setlocale is defined in the AIX Technical Reference: Base
Operating System and Extensions Volume 1.
Setting Run-Time Options
Internal switches in an XL Fortran program control run-time behavior, similar to
the way compiler options control compile-time behavior. You can set the run-time
options through either environment variables or a procedure call within the
program. You can specify all XL Fortran run-time option settings by using one of
two environment variables: XLFRTEOPTS and XLSMPOPTS.
The XLFRTEOPTS Environment Variable
The XLFRTEOPTS environment variable allows you to specify options that affect
I/O, EOF error-handling, and the specification of random-number generators. You
can declare XLFRTEOPTS by using the following ksh command format:
:
►►
XLFRTEOPTS= ▼ runtime_option_name = option_setting
" "
►◄
You can specify option names and settings in uppercase or lowercase. You can add
blanks before and after the colons and equal signs to improve readability.
However, if the XLFRTEOPTS option string contains imbedded blanks, you must
enclose the entire option string in double quotation marks (").
The environment variable is checked when the program first encounters one of the
following conditions:
v An I/O statement is executed.
v The RANDOM_SEED procedure is executed.
v An ALLOCATE statement needs to issue a run-time error message.
v A DEALLOCATE statement needs to issue a run-time error message.
v The multi-threaded implementation of the MATMUL procedure is executed.
Changing the XLFRTEOPTS environment variable during the execution of a
program has no effect on the program.
The SETRTEOPTS procedure (which is defined in the XL Fortran Enterprise Edition
for AIX Language Reference) accepts a single-string argument that contains the same
name-value pairs as the XLFRTEOPTS environment variable. It overrides the
environment variable and can be used to change settings during the execution of a
program. The new settings remain in effect for the rest of the program unless
changed by another call to SETRTEOPTS. Only the settings that you specified in
the procedure call are changed.
You can specify the following run-time options with the XLFRTEOPTS
environment variable or the SETRTEOPTS procedure:
buffering={enable | disable_preconn | disable_all}
Determines whether the XL Fortran run-time library performs buffering for
I/O operations.
The library reads data from, or writes data to the file system in chunks for
READ or WRITE statements, instead of piece by piece. The major benefit of
buffering is performance improvement.
Editing, Compiling, Linking, and Running XL Fortran Programs 51