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Technical Reference: Base Operating System and Extensions, Volume 1
The loadquery subroutine includes information for loadquery on a POWER-based platform and an
loadquery on an Itanium-based
platform.
loadquery subroutine on
POWER-based Platform
Returns error information from
the load or exec subroutine; also provides a list
of object files loaded for the current process.
int loadquery( Flags, Buffer, BufferLength)
int Flags;
void *Buffer;
unsigned int BufferLength;
The loadquery
subroutine obtains detailed information about an error reported on the last
load or exec subroutine executed by a calling
process. The loadquery subroutine may also be used to obtain
a list of object file names for all object files that have been loaded for the
current process, or the library path that was used at process exec
time.
| Buffer
| Points to a Buffer in which to store the information.
|
| BufferLength
| Specifies the number of bytes available in the Buffer
parameter.
|
| Flags
| Specifies the action of the loadquery subroutine as
follows:
- L_GETINFO
- Returns a list of all object files loaded for the current process, and
stores the list in the Buffer parameter. The object file
information is contained in a sequence of LD_INFO structures as
defined in the sys/ldr.h file. Each structure
contains the module location in virtual memory and the path name that was used
to load it into memory. The file descriptor field in the
LD_INFO structure is not filled in by this function.
- L_GETMESSAGE
- Returns detailed error information describing the failure of a previously
invoked load or exec function, and stores the error
message information in Buffer. Upon successful return from
this function the beginning of the Buffer contains an array of
character pointers. Each character pointer points to a string in the
buffer containing a loader error message. The character array ends with
a null character pointer. Each error message string consists of an
ASCII message number followed by zero or more characters of error-specific
message data. Valid message numbers are listed in the
sys/ldr.h file.
You can format the error messages returned by the L_GETMESSAGE
function and write them to standard error using the standard system
command /usr/sbin/execerror as follows:
char *buffer[1024];
buffer[0] = "execerror";
buffer[1] ="name of program that failed\ to
load";
loadquery(L_GETMESSAGES, &buffer[2],\
sizeof buffer -8);
execvp("/usr/sbin/execerror",buffer);
This sample code causes the application to terminate after the messages are
written to standard error.
- L_GETLIBPATH
- Returns the library path that was used at process exec time. The
library path is a null terminated character string.
|
Upon successful completion,
loadquery returns the requested information in the caller's
buffer specified by the Buffer and BufferLength
parameters.
The loadquery
subroutine returns with a return code of -1 and the errno global
variable is set to one of the following when an error condition is
detected:
| ENOMEM
| Indicates that the caller's buffer specified by the
Buffer and BufferLength parameters is too small to return
the information requested. When this occurs, the information in the
buffer is undefined.
|
| EINVAL
| Indicates the function specified in the Flags parameter is not
valid.
|
| EFAULT
| Indicates the address specified in the Buffer parameter is not
valid.
|
This subroutine is part of Base
Operating System (BOS) Runtime.
The exec (exec: execl, execle, execlp, execv, execve, execvp, or exect Subroutine) subroutine, load (load Subroutine) subroutine, loadbind (loadbind Subroutine) subroutine, unload subroutine.
The ld command.
Subroutines
Overview in AIX 5L Version 5.1 General Programming
Concepts: Writing and Debugging Programs.
loadquery subroutine on
Itanium-based Platform
Returns error information from the
loadsubroutine; also provides a list of object files loaded
for the current process.
int loadquery( Flags, Buffer, BufferLength)
int Flags;
void *Buffer;
unsigned int BufferLength;
The loadquery subroutine
obtains detailed information about an error reported on the last
load subroutine executed by a calling process. The
loadquery subroutine may also be used to obtain a list of object
file names for all object files that have been loaded for the current process,
or the library path that was used at process exec time.
| Buffer
| Points to a Buffer in which to store the information.
|
| BufferLength
| Specifies the number of bytes available in the Buffer
parameter.
|
| Flags
| Specifies the action of the loadquery subroutine as
follows:
- L_GETINFO
- Returns a list of all object files loaded for the current process, and
stores the list in the Buffer parameter. The object file
information is contained in a sequence of ld_info structures as
defined in the sys/ldr.h file. Each structure
contains the module location in virtual memory and the path name that was used
to load it into memory. The file descriptor field in the
ld_info structure is not filled in by this function.
- L_GETMESSAGE
- Returns detailed error information describing the failure of a previously
invoked load function, and stores the error message information in
Buffer. Upon successful return from this function the
beginning of the Buffer contains an array of character
pointers. Each character pointer points to a string in the buffer
containing a loader error message. The character array ends with a null
character pointer. Each error message string consists of an ASCII
message number followed by zero or more characters of error-specific message
data. Valid message numbers are listed in the
sys/ldr.h file.
You can format the error messages returned by the L_GETMESSAGE
function and write them to standard error using the standard system
command /usr/sbin/execerror as follows:
char *buffer[1024];
buffer[0] = "execerror";
buffer[1] ="name of program that failed \
to load";
loadquery(L_GETMESSAGES, &buffer[2],\
sizeof buffer -sizeof(int));
execvp("/usr/sbin/execerror",buffer);
This sample code causes the application to terminate after the messages are
written to standard error.
|
Upon successful completion,
loadquery returns the requested information in the caller's
buffer specified by the Buffer and BufferLength
parameters.
The loadquery subroutine
returns with a return code of -1 and the errno global variable is
set to one of the following when an error condition is detected:
| ENOMEM
| Indicates that the caller's buffer specified by the
Buffer and BufferLength parameters is too small to return
the information requested. When this occurs, the information in the
buffer is undefined.
|
| EINVAL
| Indicates the function specified in the Flags parameter is not
valid.
|
| EFAULT
| Indicates the address specified in the Buffer parameter is not
valid.
|
The exec (exec: execl, execle, execlp, execv, execve, execvp, or exect Subroutine) subroutine, load (load Subroutine) subroutine, loadbind (loadbind Subroutine) subroutine, unload subroutine.
The ld
command.
Subroutines Overview
in AIX 5L Version 5.1 General Programming Concepts: Writing
and Debugging Programs.
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