cafrun - Man Page

Coarray Fortran executable launcher for OpenCoarrays


cafrun [-s] -np <N> </path/to/coarray-executable> [arg1 [arg2 ...]]


cafrun is wrapper script which will launch Coarray Fortran executables across <N> images using the appropriate parallel runtime that OpenCoarrays was compiled against, (e.g., mpiexec(1)). cafrun ensures the correct flags are passed to the parallel runtime job launcher, as determined by system introspection at OpenCoarrays build time. Advanced users may compile their Coarray Fortran code however they please, but we recommend using the caf(1)

compiler wrapper script for a more user friendly experience.

To see the default command run by cafrun, add the -s or --show flags. To see how a specific command would be executed, simply construct the command you plan to use to launch your job, and add -s or --show as the very first flag after cafrun, e.g., cafrun -s ... to see how cafrun is translating your invocation for the parallel runtime job launcher (e.g., mpiexec(1)).


--help, -h

Print a brief help/usage message and return without performing any substantive action.

-np <N>

Mandatory flag with argument to specify the number of Coarray Fortran images to be spawned. <N> must be a positive integer.


If OpenCoarrays is built supporting failed images, which requires GFortran >= 7.0 and an MPI implementation with user level failure mitigation support (ULFM) and NOT disabling it at build time, then cafrun turns OFF mpi auto cleanup, and handles cleanup in the OpenCoarrays library. This is required to properly support failed images. --reenable-auto-cleanup re-enables the parallel runtime's auto cleanup features which breaks the failed images functionality but provides more robust error detection and application aborting. If failed images support was not enabled at OpenCoarrays build time, then this flag is a noop.

--show, -s

Print the default invocation of the underlying parallel runtime's job launcher (e.g., mpiexec), including what flags are passed, etc. This also functions as a dry-run for executing a specific cafrun command, showing the user how the compiler would be called with the additional files and arguments passed by the user.

--version, -V, -v

Print OpenCoarrays version and copyright information and exit.

--wrapping, --wraps, -w

Report the version of the parallel runtime cafrun is wrapping and exit.


For a list of bugs currently affecting OpenCoarrays, or to report a new one, please report any bugs to the OpenCoarrays project at ⟨


Izaak Beekman ⟨⟩

See Also

caf(1), mpiexec(1), gfortran(1), OpenCoarrays project page ⟨⟩, OpenCoarrays website ⟨

Referenced By


2017-09-12 OpenCoarrays-1.9.1 cafrun coarray Fortran job launcher manual