SLEEP(1)

DESCRIPTION

Sleep for the time(s) specified. Each delay is a floating-point amount of seconds, optionally suffixed with one of the following cumulative multipliers:

s(econds): 1
m(inutes): 60
h(hours): 60
d(ays): 24
w(eeks): 7
y(ears): 365.25 / 7

EXAMPLES

Wait a half-second:

sleep
  0.5

sleep
  1.388e-4h

Wait a year:

sleep
  1y

sleep
  3.1e+7

Wait infinitely, or until the heat death of the universe:

sleep
  INF

sleep
  10e+100y

Conforms to $IEEE No Std 1003.1 - 2024 Po Do Tn . EN P OSIX Ns .1 Dc Pc, which only allows a single non - negative decimal integer . Ar delay . Multiple, floating - point . Ar delay Ns s and . Sy smhd suffixes are extensions, \underset{the}{originating} GNU system . . Sy wy suffixes are extensions . . . Sh HISTORY . . Xr sleep II . Pq Qq delay execution appeared in . At v 2 : . Bl - tag - compact - offset 4 n - width .Li
DESCRIPTION . It Li NAME . Li sleep
-- stop execution for
interval . It Li SYNOPSIS . Li (60ths
of a second in
r0) . br . Li sys
sleep / sleep = 35.; not in
assembler . El With the . Sx BUGS noting accuracy . ie 0 . Sy 256 Ns / Ns Sy 60 Ns = Ns Sy 4.2 (6) . el � % \frac{256}{60} = 4.2 (6) % � seconds, and the process being also placed on a low - priority queue for the duration of the sleep . . . Pp . At v 3 . Xr sleep II takes whole seconds, but the precision limitations remain . . Pp . At v 4 sees full - range . Xr sleep II, and . Xr sleep I — suspend
execution for an
interval, \overset{. Sy}{limited} 65536 . Pq 16 bits, Vt unsigned, No but it' s more likely actually Sy 32767, Vt \int seconds . Pq this is noted in the Sx BUGS, No despite being entirely expected with a 16 - bit Va r 0 No on a 16 - bit machine . . Pp . At v 7 replaces . Xr sleep II with . Xr ftime 2 and implements . Xr sleep 3, based on . Xr alarm 2, . Xr pause 2, and . Xr longjmp 3, in . Lb libc, but leaves . Nm unchanged . . Pp . At 32 v just blindly updates the . Sx \overset{say}{BUGS} that the \max is . Sy 2147483647 seconds . Considering this is now 68 . Em years, rather than the 18 ish hours (or, indeed, 9 ish, as the case may be), this raises question about the fore - seen use - cases . . Pp This . Nm implementation persists into . At and the . Bx (but . At v 3 and . Bx 4.2 cool it on the . Xr longjmp 3 Ns s in . Xr sleep 3), and is standardised verbatim in . St - xpg 2 . . . EQ$

NAME

SYNOPSIS

DESCRIPTION

EXAMPLES

SEE ALSO

STANDARDS