HP-UX Reference (11i v3 07/02) - 5 Miscellaneous Topics (vol 9)

pthread_stubs(5) pthread_stubs(5)

$ cc +DA2.0W thread.c -L. -l1 -l2

$ a.out

Error

$ ldd a.out

lib1.sl => ./lib1.sl

lib2.sl => ./lib2.sl

libc.2 => /usr/lib/pa20_64/libc.2

libpthread.1 => /lib/pa20_64/libpthread.1

libdl.1 => /usr/lib/pa20_64/libdl.1

$ LD_PRELOAD="/lib/pa20_64/libpthread.1" a.out

Success

a.out correctly lists -lpthread for a threaded application.

$ ld -b -o lib1.sl lib1.o

$ ld -b -o lib2.sl -lpthread lib2.o

$ cc +DA2.0W thread.c -L. -l1 -l2 -lpthread

$ a.out

Success

$ ldd a.out

lib1.sl => ./lib1.sl

lib2.sl => ./lib2.sl

libpthread.1 => /usr/lib/pa20_64/libpthread.1

libc.2 => /usr/lib/pa20_64/libc.2

libpthread.1 => /lib/pa20_64/libpthread.1

libdl.1 => /usr/lib/pa20_64/libdl.1

Example 4 (archived libc)

If the link line of your shared library contains -lc to explicitly link in libc, remove

-lc.Otherwise,

shared libraries may be referencing

libc.2 while the a.out may refer to older (archived) libc version.

Thus the application will actually be using two different versions of

libc and possibly mixing the code.

This may cause compatibility problems. Basically, an application or library should never directly link

against

libc. All programs need to be linked against libc (which the compiler does automatically), so a

shared library will always have the interfaces it needs to execute properly without needing to specify -lc

on the link line.