1nice(3UCB) SunOS/BSD Compatibility Library Functions nice(3UCB)
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6 nice - change priority of a process
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9 /usr/ucb/cc [ flag ... ] file ...
10 #include<unistd.h>
11 int nice(incr)
13 int incr;
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17 The scheduling priority of the process is augmented by incr. Positive
18 priorities get less service than normal. Priority 10 is recommended to
19 users who wish to execute long-running programs without undue impact on
20 system performance.
21 Negative increments are illegal, except when specified by the privi‐
24 leged user. The priority is limited to the range −20 (most urgent) to
25 20 (least). Requests for values above or below these limits result in
26 the scheduling priority being set to the corresponding limit.
27 The priority of a process is passed to a child process by fork(2). For
30 a privileged process to return to normal priority from an unknown
31 state, nice() should be called successively with arguments −40 (goes to
32 priority −20 because of truncation), 20 (to get to 0), then 0 (to main‐
33 tain compatibility with previous versions of this call).
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36 Upon successful completion, nice() returns 0. Otherwise, a value of −1
37 is returned and errno is set to indicate the error.
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40 The priority is not changed if:
41 EPERM The value of incr specified was negative, and the effective
43 user ID is not the privileged user.
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47 nice(1), renice(1), fork(2), priocntl(2), getpriority(3C)
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50 Use of these interfaces should be restricted to only applications writ‐
51 ten on BSD platforms. Use of these interfaces with any of the system
52 libraries or in multi-threaded applications is unsupported.
53SunOS 5.11 30 Oct 2007 nice(3UCB)