Library Naming Conventions

By convention, library names have the form:

libname. suffix

name

is a string of one or more characters that identifies the library.

suffix

is .a if the library is an archive library, .sl if the library is a PA-RISC shared library,

 

or .so if the library is a shared library. (The suffix can be .sl for an IPF shared library.

 

This naming convention is not recommended, but it is supported for backwards

 

compatibility with PA-32 and PA-64.)

Typically, library names are referred to without the suffix. For instance, the standard C library is referred to as libc.

Default Libraries

A compiler driver automatically specifies certain default libraries when it invokes ld. For example, cc automatically links in the standard library libc, as shown by the -lc option to ld in this example:

$ cc -Aa -v main.c func.c

...

/usr/ccs/bin/ld -o a.out -u__exit -umain main.o func.o -lc cc: informational note 413: Entering Link editor.

Similarly, the Series 700/800 Fortran90 compiler automatically links with the libcl (C interface), libisamstub (ISAM file I/O), and libc libraries:

$ f90 -v sumnum.f

...

/usr/ccs/bin/ld -x /opt/langtools/lib/crt0.o \ sumnum.o -lcl -lisamstub -lc

The Default Library Search Path

Following are the default search paths for the libraries:

•On Itanium systems, ld searches for libraries in the directory /usr/lib/hpux32 for 32-bit executables and /usr/lib/hpux64 for 64-bit executables.

•On PA-RISC systems, ld searches for libraries in the directory /usr/lib/ for 32-bit executables and /usr/lib/pa20_64/ for 64-bit executables.

If the -por -Gcompiler profiling option is specified on the command line, the compiler directs the linker to also search:

/usr/lib/libp (for PA32) /usr/lib/pa20__64/libp (for PA64) /usr/lib/hpux32/libp (for IPF 32-bit) /usr/lib/hpux64/libp (for IPF 64-bit)

The default order can be overridden with the LPATH environment variable, the -Llinker option, specifies $ORIGIN in the library path, or the +origin option. These are described in Changing the“Changing the Default Library Search Path with -L, LPATH, and $ORIGIN” (page 30) .

Link Order

The linker searches libraries in the order in which they are specified on the command line - the link order. Link order is important in that a library containing an external reference to another library must precede the library containing the definition. This is why libc is typically the last

24 Compiling and Linking Programs on HP-UX