4.5.5 A Simple Dynamic Library

Building a dynamic library requires a compilation of the source files with the -xcode option and linker options -G, -ztext, and -hname. These linker options are available through the compiler command line.

You can create a dynamic library with the same files used in the static library example.

Example: Compile with -pic and other linker options:

demo% f95 -o libtestlib.so.1 -G -xcode=pic13 -ztext  \ 
–hlibtestlib.so.1 *.f

–G tells the linker to build a dynamic library.

–ztext warns you if it finds anything other than position-independent code, such as relocatable text.

Example: Make an executable file a.out using the dynamic library:

demo% f95 -o trylib -R”pwd” trylib.f libtestlib.so.1
demo% file trylib
trylib:ELF 32–bit MSB executable SPARC Version 1, dynamically linked, not stripped
demo% ldd trylib
     libtestlib.so.1 => /export/home/U/Tests/libtestlib.so.1
     libfui.so.1 => /opt/SUNWspro/lib/libfui.so.1
     libfai.so.1 => /opt/SUNWspro/lib/libfai.so.1
     libc.so.1 => /usr/lib/libc.so.1

Note that the example uses the -R option to bind into the executable the path (the current directory) to the dynamic library.

The file command shows that the executable is dynamically linked.