shl_load_pa.3x (2010 09)

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shl_load_pa(3X)

PA-RISC Systems Only

shl_load_pa(3X)

NAME

shl_load_pa: shl_load(), shl_deﬁnesym(), shl_ﬁndsym(), shl_get(), shl_get_r(), shl_gethandle(),

shl_gethandle_r(), shl_getsymbols(), shl_unload(), dld_getenv() - explicit load of shared libraries for PA-

RISC systems

SYNOPSIS

#include <dl.h>

shl_t shl_load(const char *path, int flags, long address);

int shl_findsym(

shl_t *handle,

const char *sym,

short type,

void *value

);

int shl_definesym(

const char *sym,

short type,

long value,

int flags

);

int shl_getsymbols(

shl_t handle,

short type,

int flags,

void *(*memory) (),

struct shl_symbol **symbols,

);

int shl_unload(shl_t handle);

int shl_get(int index, struct shl_descriptor **desc);

int shl_gethandle(shl_t handle, struct shl_descriptor **desc);

int shl_get_r(int index, struct shl_descriptor *desc);

int shl_gethandle_r(shl_t handle, struct shl_descriptor *desc);

void dld_getenv();

Remarks

This manpage describes shl*() routines on PA-RISC systems. For

shl*() routines on Integrity sys-

tems, see shl_load_ia (3X).

DESCRIPTION

These routines can be used to programmatically load and unload shared libraries, and to obtain informa-

tion about the libraries (such as the addresses of symbols deﬁned within them). On PA-RISC 32-bit sys-

tems, the routines themselves are accessed by specifying the

-ldld option on the command line with the

cc or ld command (see cc(1) and ld(1)). On PA-RISC 64-bit systems, the routines are accessed by speci-

fying either -ldld or -ldl on the command line. See WARNINGS . In addition, the -E option to the

ld command can be used to ensure that all symbols deﬁned in the program are available to the loaded

libraries. This is the default behavior on PA-RISC 64-bit systems.

Shared libraries are created by compiling source ﬁles and linking the resultant object ﬁles with the

-b

(create shared library) option.

shl_load()

Attaches the shared library named by path or the shared library name that is constructed by using

the path part of path plus the shared library basename followed by the sufﬁx .0 (e.g.

/usr/lib/pa20_64/libname.0) to the process, along with all its dependent libraries. A .0

version is looked for ﬁrst for those shared libraries that do not have internal names. See ld(1)).

The library is mapped at the speciﬁed address .Ifaddress is 0L, the system chooses an appropriate

address for the library. This is the recommended practice because the system has the most complete

knowledge of the address space; currently, the address ﬁeld is ignored, and assumed to be 0L.If

the shared library contains thread local storage, you cannot load it with this routine.

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (6 pages)

PAGE 1
shl_load_pa(3X) shl_load_pa(3X) PA-RISC Systems Only NAME shl_load_pa: shl_load(), shl_definesym(), shl_findsym(), shl_get(), shl_get_r(), shl_gethandle(), shl_gethandle_r(), shl_getsymbols(), shl_unload(), dld_getenv() - explicit load of shared libraries for PARISC systems SYNOPSIS #include
PAGE 2
shl_load_pa(3X) shl_load_pa(3X) PA-RISC Systems Only The flags argument is made up of several fields. One of the following must be specified: BIND_IMMEDIATE Resolve symbol references when the library is loaded. BIND_DEFERRED Delay code symbol resolution until actual reference. Zero or more of the following can be specified by doing a bitwise OR operation: BIND_FIRST Place the library at the head of the symbol search order.
PAGE 3
shl_load_pa(3X) shl_load_pa(3X) PA-RISC Systems Only address of the shared library + the offset of the symbol in the library. This routine returns 0 if successful; otherwise −1 is returned. See DIAGNOSTICS for errno settings. shl_definesym() Adds a symbol to the user hash table for the current process. If value falls in the range of a currently loaded library, an association will be made and the symbol is undefined once the associated library is unloaded.
PAGE 4
shl_load_pa(3X) PA-RISC Systems Only shl_load_pa(3X) struct shl_symbol { char *name, short type, void *value, shl_t handle, }; The type field in the return structure can have the values TYPE_PROCEDURE, or TYPE_DATA. On PA-RISC 32i-bit systems, you can also have the values TYPE_STORAGE or TYPE_TSTORAGE. These are a subset of TYPE_DATA. The value and handle fields are only valid if export symbols are requested and the NO_VALUES flag is not specified.
PAGE 5
shl_load_pa(3X) shl_load_pa(3X) PA-RISC Systems Only MULTITHREAD USAGE These routines are safe to be called from multithreaded applications. Note: The 32-bit dynamic loader dld.sl serializes the loading and unloading of shared libraries in multithreaded applications using a pthread mutex lock. See the HP-UX Linker and Libraries Online User Guide for more information. DIAGNOSTICS If a library cannot be loaded, shl_load() returns NULL and sets errno to indicate the error.
PAGE 6
shl_load_pa(3X) SEE ALSO System Tools ld(1) Miscellaneous dld.