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       renice - set nice values of running processes


       renice -n increment [-g | -p | -u] ID ...


       The  renice utility shall request that the nice values (see the Base Definitions volume of
       IEEE Std 1003.1-2001, Section 3.239, Nice Value) of  one  or  more  running  processes  be
       changed.  By default, the applicable processes are specified by their process IDs.  When a
       process group is specified (see -g), the request shall  apply  to  all  processes  in  the
       process group.

       The  nice  value  shall  be bounded in an implementation-defined manner.  If the requested
       increment  would  raise  or  lower  the  nice  value  of  the  executed   utility   beyond
       implementation-defined limits, then the limit whose value was exceeded shall be used.

       When  a  user  is  reniced,  the  request applies to all processes whose saved set-user-ID
       matches the user ID corresponding to the user.

       Regardless of which options are supplied or any other factor, renice shall not  alter  the
       nice  values  of  any  process  unless  the  user requesting such a change has appropriate
       privileges to do so for the specified process. If the user lacks appropriate privileges to
       perform the requested action, the utility shall return an error status.

       The saved set-user-ID of the user's process shall be checked instead of its effective user
       ID when renice attempts to determine the user ID of the  process  in  order  to  determine
       whether the user has appropriate privileges.


       The  renice  utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001,
       Section 12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       -g     Interpret all operands as unsigned decimal integer process group IDs.

       -n  increment
              Specify how the nice value of the specified process or processes is to be adjusted.
              The  increment option-argument is a positive or negative decimal integer that shall
              be used to modify the nice value of the specified process or processes.

       Positive increment values shall cause a lower nice value. Negative  increment  values  may
       require appropriate privileges and shall cause a higher nice value.

       -p     Interpret  all  operands  as unsigned decimal integer process IDs. The -p option is
              the default if no options are specified.

       -u     Interpret all operands as users. If a user exists with a user  name  equal  to  the
              operand, then the user ID of that user is used in further processing. Otherwise, if
              the operand represents an unsigned decimal integer, it shall be used as the numeric
              user ID of the user.


       The following operands shall be supported:

       ID     A  process  ID,  process  group  ID,  or user name/user ID, depending on the option


       Not used.




       The following environment variables shall affect the execution of renice:

       LANG   Provide a default value for the internationalization variables that  are  unset  or
              null.  (See  the  Base  Definitions  volume  of  IEEE Std 1003.1-2001, Section 8.2,
              Internationalization Variables for the precedence of internationalization variables
              used to determine the values of locale categories.)

       LC_ALL If  set  to  a  non-empty  string  value,  override  the  values  of  all the other
              internationalization variables.

              Determine the locale for the interpretation of sequences of bytes of text  data  as
              characters  (for  example,  single-byte  as  opposed  to  multi-byte  characters in

              Determine the locale that should be used to  affect  the  format  and  contents  of
              diagnostic messages written to standard error.

              Determine the location of message catalogs for the processing of LC_MESSAGES .




       Not used.


       The standard error shall be used only for diagnostic messages.






       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.



       The following sections are informative.




        1. Adjust the nice value so that process IDs 987 and 32 would have a lower nice value:

           renice -n 5 -p 987 32

        2. Adjust  the nice value so that group IDs 324 and 76 would have a higher nice value, if
           the user has the appropriate privileges to do so:

           renice -n -4 -g 324 76

        3. Adjust the nice value so that numeric user ID 8 and user sas would have a  lower  nice

           renice -n 4 -u 8 sas

       Useful  nice  value  increments  on  historical  systems  include  19  or 20 (the affected
       processes run only when nothing else in the system  attempts  to  run)  and  any  negative
       number (to make processes run faster).


       The  gid,  pid,  and  user  specifications  do not fit either the definition of operand or
       option-argument.  However, for clarity, they have been included in  the  OPTIONS  section,
       rather than the OPERANDS section.

       The  definition  of  nice  value is not intended to suggest that all processes in a system
       have priorities that are comparable.  Scheduling policy extensions such  as  the  realtime
       priorities  in  the  System Interfaces volume of IEEE Std 1003.1-2001 make the notion of a
       single underlying priority for all scheduling policies problematic.  Some  implementations
       may  implement  the nice-related features to affect all processes on the system, others to
       affect  just  the  general   time-sharing   activities   implied   by   this   volume   of
       IEEE Std 1003.1-2001,  and  others  may  have  no  effect  at  all.  Because of the use of
       "implementation-defined" in nice and renice, a wide range of implementation strategies are

       Originally,  this  utility  was  written  in  the  historical manner, using the term "nice
       value". This was always a point of concern with users because  it  was  never  intuitively
       obvious  what  this  meant.   With  a newer version of renice, which used the term "system
       scheduling priority", it was hoped that novice users could  better  understand  what  this
       utility  was  meant to do. Also, it would be easier to document what the utility was meant
       to  do.  Unfortunately,  the  addition  of  the  POSIX  realtime  scheduling  capabilities
       introduced  the  concepts  of  process  and thread scheduling priorities that were totally
       unaffected  by  the  nice/  renice  utilities  or  the  nice()/  setpriority()  functions.
       Continuing  to use the term "system scheduling priority'' would have incorrectly suggested
       that these utilities and functions were indeed affecting these realtime priorities. It was
       decided  to revert to the historical term "nice value" to reference this unrelated process

       Although this utility has use by system administrators (and in fact appears in the  system
       administration  portion of the BSD documentation), the standard developers considered that
       it was very useful for individual end users to control their own processes.






       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at .