Index for Section 2

Alphabetical listing for E

exec_with_loader(2)
NAME
  exec_with_loader - Executes a file with a loader

SYNOPSIS
  int exec_with_loader (
	  int flags,
	  const char *loader,
	  const char *file,
	  char * const argv[ ],
	  char * const envp[ ] );

PARAMETERS
  flags	    Specifies flags to be passed to the loader.

  loader    Points to a pathname that identifies a regular, executable,
	    process image file that contains the loader.  This image file
	    must be a nonshared image.

  file	    Points to a pathname that identifies a regular, executable
	    process image file.	 This image file must be a call-shared image.

  argv	    Specifies an array of character pointers to null-terminated
	    strings.

  envp	    Specifies an array of character pointers to null-terminated
	    strings, constituting the environment for the new process.

DESCRIPTION
  The exec_with_loader() function replaces the current process image with a
  new process image, in a manner similar to what the exec functions do.	 Both
  the loader parameter and the file parameter point to pathnames that
  identify regular, executable files called new process image files.  Whereas
  the exec functions construct the new process image from the file identified
  by the file parameter, exec_with_loader() instead constructs the new
  process image from the file identified by the loader parameter.  Throughout
  this manual page, the regular, executable, process image file specified by
  the loader parameter is referred to as the program loader, and the regular,
  executable, process image file specified by the file parameter is referred
  to as the file.  The loader image cannot be linked at the default user
  addresses.  You must find another place to link it.  One acceptable place
  to link the loader image is at the address space defined for the loader in
  the /usr/shlilb/so_locations file.

  Once the exec_with_loader() function successfully loads the program loader,
  it transfers control to the program loader and effectively passes the file
  parameter on to the loader.  Under normal usage, the program loader will
  then load (that is, merge) the file into the newly constructed process
  image, along with any object files upon which the program (that is, the
  file) depends.  The typical use of exec_with_loader() is to load programs
  that contain unresolved external references, for example, programs that
  require the use of a shared library.

  The exec_with_loader() function implements and preserves all of the
  semantics of the exec functions, with respect to the file.  These include
  the handling of the argv and envp parameters, command interpreters, close-
  on-exec processing, signals, set user ID and set group ID processing, the
  process attributes and error returns.

  The loader parameter may be null, in which case the exec_with_loader()
  function loads the default program loader, found in the /sbin/loader file.
  The exec_with_loader() function always loads the default program loader,
  even if the loader parameter points to a valid loader file, if the set user
  ID mode bit of the file is set (see the chmod() function) and the owner ID
  of the file is not equal to the effective user ID of the process, or if the
  set group ID mode bit of the file is set and the group ID of the file is
  not equal to the effective group ID of the process.  The setting of the set
  user ID or set group ID mode bits on the loader have no effect whatsoever.

RETURN VALUES
  If the exec_with_loader() function returns to the calling process image, an
  error has occurred; the return value is -1, and errno is set to indicate
  the error.

ERRORS
  If the exec_with_loader() function fails, errno may be set to one of the
  following values:

  [EACCES]  Search permission is denied for a directory listed in either
	    file's path prefix, or either file denies execution permission,
	    or either file is not a regular file and the implementation does
	    not support execution of files of its type.	 Note that the
	    exec_with_loader() function references two files, one specified
	    by the loader parameter and one specified by the file parameter.

  [ENAMETOOLONG]
	    The length of the loader or file parameters exceeds PATH_MAX, or
	    a pathname component is longer than NAME_MAX and _POSIX_NO_TRUNC
	    is in effect for that file.

  [ENOENT]  One or more components of either file's pathname does not exist,
	    or the loader or file parameter points to an empty string.	Note
	    that the exec_with_loader() function references two files, one
	    specified by the loader parameter and one specified by the file
	    parameter.

  [ENOTDIR] A component of either file's path prefix is not a directory.
	    Note that the exec_with_loader() function references two files,
	    one specified by the loader parameter and one specified by the
	    file parameter.

  [ENOEXEC] The file specified by the loader parameter has the appropriate
	    access permission but is not in the proper format.

  [EFAULT]  The loader or file parameter is an invalid address.

  [ELOOP]   Too many symbolic links were encountered in pathname resolution.

  [ENOMEM]  Insufficient memory is available.

RELATED INFORMATION
  Functions: exec(2)