```{index} single: nice; POSIX function ``` ```{index} single: POSIX::nice; Perl function ``` # nice Adjust the current process's scheduling niceness by `$incr`. ## Synopsis ```perl POSIX::nice(5); # lower priority ``` ## What you get back The new niceness value. When the new value genuinely is `0`, returns the string `"0 but true"` to distinguish it from error. On error, returns `undef` and sets `$!`. ## Edge cases - Positive increments lower priority; only root can pass negative values to raise priority. ## Differences from upstream Fully compatible with upstream POSIX.