As with the C/C++/Fortran compilers, you can set an environment variable before running configure to set compiler flags. If you do not specify any of these flags, configure will choose suitable optimization flags for your architecture (such as -O or -fast).

For example, to enable debugging support for the LAM C and C++ libraries (i.e., to enable debugging support within the LAM functions when debugging user code):

with a C shell or C shell derrivative:

shell% cd lam-7.1.1
shell% setenv CFLAGS -g
shell% setenv CXXFLAGS -g
shell% ./configure

or, with the sh or derivative shell:

shell$ cd lam-7.1.1
shell$ CFLAGS=-g
shell$ CXXFLAGS=-g
shell$ export CFLAGS CXXFLAGS
shell$ ./configure

Just as with the compile flags, you can set the environment variable LDFLAGS before you run configure:

For example, to enable debugging support for all LAM executables:

with a C shell or C shell derrivative:

shell% cd lam-7.1.1
shell% setenv LDFLAGS -g
shell% ./configure

or with sh or derivative shell:

shell$ cd lam-7.1.1 
shell$ LDFLAGS=-g
shell$ export LDFLAGS
shell$ ./configure

Generally, you will have to specify C, C++, and Fortran flags in the configuration step. However, each vendor's compiler flags are different. For example, the following will configure LAM for 64 bit mode under using the Solaris Forte 6.0 compilers (using Bourne-like shells):

shell$ CFLAGS="-xarch=v9"
shell$ CXXFLAGS="-xarch=v9"
shell$ FFLAGS="-xarch=v9"
shell$ export CFLAGS CXXFLAGS FFLAGS
shell$ ./configure ...

LAM/MPI uses GNU Libtool to build its libraries. Hence, all LAM/MPI supports all platforms that Libtool supports.

Starting with LAM 7.0, the message passing mechanism selection is a run-time option. See the Running LAM/MPI Applications section of the FAQ for more information.

If you do not specify one, the configure script will choose a remote shell program appropriate for your architecture. You can override the default with the --with-rsh option to configure. You can specify a different remote shell program, and optionally specify command line options for it (be sure to put them in quotes). This may be necessary at some sites where rsh is disabled for security reasons.

For example, to specify the ssh secure shell program, use:

shell% cd lam-7.1.1 
shell% ./configure --with-rsh="/bin/ssh -x"

Note that the -x option to ssh may be necessary for the 1.x series of ssh clients. -x disables X forwarding; using X forwarding will trigger a status message from xauth that ssh outputs to the standard error. Any output in the standard error will cause LAM binaries to fail (because they assume that an error has occurred). The -p option may also be helpful in suppressing stderr output; see the ssh documentation.

The compiled-in value for the remote shell program can be overriden at run-time by the user by setting the LAMRSH environment variable. Using this option only sets the default remote shell program that LAM will use if the user does not override it.

For example, to specify the ssh secure shell program, use (with a Bourne shell, or sh derrivative):

shell$ LAMRSH="ssh -x"
shell$ export LAMRSH
shell$ mpirun ...

shell% setenv LAMRSH "ssh -x"
shell% mpirun ...

Note that the -x option to ssh is necessary for the 1.x series of ssh clients. -x disables X forwarding; using X forwarding will trigger a status message from xauth that ssh outputs to the standard error. Any output in the standard error will cause LAM binaries to fail (because they assume that an error has occurred). The -p option may also be helpful in suppressing stderr output; see the ssh documentation.

By default, LAM uses SIGUSR2 internally for some of its signalling. LAM must use some signal -- but it does not need to be SIGUSR2. You can change it with the --with-signal command line argument to configure.

As the argument to the --with-signal option, you can use either a name that is defined in signal.h or an integer number. It is probably safer to use a name from signal.h.

For example, to change the signal that LAM uses internally to SIGUSR1:

shell% cd lam-7.1.1 
shell% ./configure --with-signal=SIGUSR1

ROMIO support is now enabled by default (it wasn't in prior versions of LAM/MPI).

If you do not wish to build LAM with the MPI 2 C++ bindings, you can use the --without-mpi2cpp option to configure. Note that you still must have a C++ compiler available to build LAM 7.0 and later.

Simply type make and LAM will build itself. To install LAM, use the command make install and LAM will install itself into the tree specified with the --prefix option (or /usr/local, if not specified).