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32 .\" @(#)sleep.1 8.3 (Berkeley) 4/18/94
40 .Nd suspend execution for an interval of time
43 .Ar number Ns Op Ar unit
48 command suspends execution for a minimum of
50 seconds (the default, or unit
58 If multiple arguments are passed, the delay will be the sum of all values.
62 command receives a signal, it takes the standard action.
65 signal is received, the estimate of the amount of seconds left to
66 sleep is printed on the standard output.
67 .Sh IMPLEMENTATION NOTES
70 signal is not handled specially by this implementation.
74 command supports other time units than seconds,
75 honors a non-integer number of time units to sleep in any form acceptable by
77 and accepts more than one delay value.
78 These are non-portable extensions, but they have also been implemented
79 in GNU sh-utils since version 2.0a (released in 2002).
83 To schedule the execution of a command for
85 number seconds later (with
88 .Dl (sleep 1800; sh command_file >& errors)&
90 This incantation would wait a half hour before
91 running the script command_file.
96 To reiteratively run a command (with the
99 .Bd -literal -offset indent -compact
101 if (! -r zzz.rawdata) then
104 foreach i (`ls *.rawdata`)
106 awk -f collapse_data $i >> results
113 The scenario for a script such as this might be: a program currently
114 running is taking longer than expected to process a series of
115 files, and it would be nice to have
116 another program start processing the files created by the first
117 program as soon as it is finished (when zzz.rawdata is created).
118 The script checks every five minutes for the file zzz.rawdata,
119 when the file is found, then another portion processing
120 is done courteously by sleeping for 70 seconds in between each
128 command is expected to be