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

Answers to Frequently Asked Questions
Finding the Date and Time
Efficient Static Linking
Here are the answers to some questions that are often asked by users of XL
Fortran. Many of these questions are answered elsewhere in the XL Fortran
documentation, but they are also collected here for your convenience.
There are some common date and time subprograms that you may be familiar
with from programming in FORTRAN 77 on other systems. XL Fortran provides
equivalents to many of these subprograms. Some of the names have trailing
underscores to avoid conflicts with C library functions of the same name.
The XL Fortran subprograms that deal with the date and time are:
alarm_
clock_
ctime_
date
dtime_
etime_
fdate_
gmtime_
idate_
irtc
itime_
jdate
ltime_
rtc
sleep_
time_
timef
usleep_
See the section on Service and Utility Procedures in the XL Fortran Enterprise Edition
for AIX Language Reference for details about these subprograms.
For portable Fortran 90 and Fortran 95 programming, you can also use the
CPU_TIME, DATE_AND_TIME, and SYSTEM_CLOCK intrinsic subroutines.
“Dynamic and Static Linking” on page 46 discusses the respective strengths and
weaknesses of static and dynamic linking. A technique for static linking that
requires relatively little disk space is to link any XL Fortran libraries statically but
leave references to other system libraries dynamic. This example statically links just
the XL Fortran library:
# Build a temporary object:
ld -r -o libtmp.o -bnso -lxlf90
# Build the application with this object on the command line:
xlf95 -o appl appl1.o appl2.o libtmp.o
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