Index for Section 2

Alphabetical listing for G

Bottom of page

getpriority(2)
NAME
  getpriority, setpriority - Get or set process scheduling priority

SYNOPSIS
  #include <sys/resource.h>

  int getpriority(
	  int which,
	  id_t who );

  int setpriority(
	  int which,
	  id_t who,
	  int priority) );

  [Tru64 UNIX]	The following declaration of the who parameter for
  getpriority() and setpriority() does not conform to current standards and
  is supported only for backward compatibility:

  int who

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  getpriority(), setpriority(): XSH4.2, XSH5.0

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  which
      Specifies one of PRIO_PROCESS (process priority), PRIO_PGRP (process
      group priority), or PRIO_USER (user priority).

  who Specifies a numeric value interpreted relative to the which parameter
      (a process identifier, process group identifier, and a user ID,
      respectively).  A 0 (zero) value for the who parameter denotes the
      current process, process group, or user.

  priority
      Specifies a value in the range -20 to 20. The default priority is 0
      (zero); negative priorities cause more favorable scheduling.

DESCRIPTION
  The getpriority() function obtains the current priority of a process,
  process group, or user. The getpriority() function returns the highest
  priority (lowest numerical value) pertaining to any of the specified
  processes.

  The setpriority() function sets the scheduling priority of a process,
  process group, or user. If you specify more than one process, the
  setpriority() function sets the priorities of all of the specified
  processes to the specified value.  If the specified value is less than -20,
  a value of -20 is used; if it is greater than 20, a value of 20 is used.

RETURN VALUES
  Upon successful completion, the getpriority() function returns an integer
  in the range -20 to 20. Otherwise, -1 is returned and errno is set to
  indicated the error.

  Because getpriority() can legitimately return the value -1, it is necessary
  to clear the external variable errno prior to the call, then check it
  afterward to determine if -1 is an error or a legitimate value.

  Upon successful completion, the setpriority() function returns 0 (zero).
  Otherwise, the function returns -1 and sets errno to indicate the error.

ERRORS
  The getpriority() and setpriority() functions set errno to the specified
  values for the following conditions:

  [ESRCH]
      No process was located using the specified which and who parameter
      values.

  [EINVAL]
      The which parameter was not recognized.

  In addition to the errors indicated above, the setpriority() function can
  fail with errno set to one of the following values:

  [EPERM]
      The process does not have ownership rights with respect to the target
      process's real user ID.

  [EACCES]
      The process is trying to raise its priority and does not have the
      appropriate privilege.

SEE ALSO
  Functions: exec(2), nice(3)

  Standards: standards(5)

Index for Section 2

Alphabetical listing for G

Top of page