HP Fortran Programmer's Guide (B3908-90031; September 2011)

Compiling and linking
Using environment variables
Chapter 298
The syntax of the HP_F90OPTS variable allows the bar (|) character to be used to specify that options
appearing before | are to be recognized before any options on the command line and that options appearing
after | are to be recognized after any options on the command line. For example, the commands:
$ export HP_F90OPTS="-O|-lmylib"
$ f90 -v hello.f90
are equivalent to:
$ f90 -O -v hello.f90 -lmylib
If you are programming in the csh, the command line to define HP_F90OPTS would be:
% setenv HP_F90OPTS "-O|-lmylib"
LPATH environment variable
The LPATH environment variable is read by the linker to determine where to look for libraries to link with a
program’s object file. Depending on whether LPATH is set or not, one of the following actions occurs:
•If LPATH is already set, only the directories listed in LPATH are searched. This happens, for example,
when LPATH is set in a user’s .kshrc or .cshrc file, or after LPATH is defined from the command
line.
•If LPATH is not set, the f90 command sets default LPATH settings that are used when linking the object
files listed on the f90 command line.
Because the f90 command sets LPATH before calling the linker, it should not be necessary to set this
variable for most compilations. However, if you do need to set it (for example, you use the ld command to
link), the following directories should be the first items in LPATH:
• /opt/fortran90/lib
• /usr/lib
• /opt/langtools/lib
The following command lines set LPATH to include these directories, using (respectively) the ksh and csh
syntax:
$ export LPATH:/opt/fortran90/lib:/usr/lib:/opt/langtools/lib
% setenv LPATH "/opt/fortran90/lib:/usr/lib:/opt/langtools/lib"
To see how f90 sets LPATH before calling the linker, compile with the -v option for verbose output. For an
example, see “Linking with f90 vs. ld” on page 78.