Link with the UnifyFS library

This section describes how to link an application with the UnifyFS library. The UnifyFS library contains symbols for the UnifyFS API, like unifyfs_mount, as well as wrappers for I/O routines, like open, write, and close. In the examples below, replace <unifyfs> with the path to your UnifyFS install.

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Static link

For a static link, UnifyFS utilizes the --wrap feature of the ld command. One must specify a --wrap option for every I/O call that is wrapped, for which there are many. To make this easier, UnifyFS installs a unifyfs-config script that one should invoke to specify those flags, e.g.,

$ mpicc -o test_write \
      `<unifyfs>/bin/unifyfs-config --pre-ld-flags` \
      test_write.c \
      `<unifyfs>/bin/unifyfs-config --post-ld-flags`

Dynamic link

To intercept I/O calls using gotcha, use the following syntax to link an application:

C

$ mpicc -o test_write test_write.c \
    -I<unifyfs>/include -L<unifyfs>/lib -lunifyfs_gotcha \
    -L<gotcha>/lib64 -lgotcha

Fortran

$ mpif90 -o test_write test_write.F \
    -I<unifyfs>/include -L<unifyfs>/lib -lunifyfsf -lunifyfs_gotcha