User's Manual

Example 16 Specifying library paths in PA-32 mode and IPF/PA-64 mode
The following are examples of specifying library paths in PA-32 mode and IPF/PA-64 mode (IPF
(32-bit and 64-bit) and PA-64):
• Linking to libraries by fully qualifying paths. The library does not contain SONAME specified
by the linker +h option when building the shared library: In this example, the program is
linked with /opt/myapp/mylib.sl:
$ cc main.o /opt/myapp/mylib.sl
Perform 32-bit link.
$ cc +DD64 main.o /opt/myapp/mylib.sl
Perform 64-bit link.
At run-time, in both 32-bit and 64-bit mode, the dynamic loader only looks in /opt/myapp
to find mylib.sl.
• Linking to libraries using -l library or -l:library options:
In this example, the +s option is not explicitly enabled at link time. Both 32-bit and 64-bit
versions of a shared library called libfoo.sl exist in the default location.
◦ PA-32 and IPF 32-bit mode example:
$ cc main.o -lfoo -o main
Perform 32-bit link.
With the +DD32 default, when linked in PA-32 mode, main aborts at run time if
libfoo.sl is moved from /usr/lib. This is because the absolute path name of the
shared library /usr/lib/libfoo.sl is stored in the executable.
When linked in IPF 32-bit mode, main does not abort at run time if libfoo.sl is moved
from /usr/lib/hpux32 as long as LD_LIBRARY_PATH or SHLIB_PATH is set and
point to libfoo.sl.
◦ PA-64 and IPF 64-bit mode example:
$ cc +DD64 main.o -lfoo -o main
Perform 64-bit link.
When linked in IPF or PA-64 mode, main does not abort at run time if libfoo.sl is
moved, as long as LD_LIBRARY_PATH or SHLIB_PATH is set and point to
libfoo.sl.
• Linking to libraries using -L and +b path_list:
The -L option is used by the linker to locate libraries at link time. The +b option is used to
embed a library path list in the executable for use at run time.
◦ PA-32, IPF 32-bit mode example:
$ cc main.o -L. -Wl,+b/var/tmp -lme
Link the program.
$ mv libme.sl /var/tmp/libme.sl
Move libme.sl.
$ a.out
Run the program.
Dynamic Path Searching for Shared Libraries 85