4.4BSD/usr/share/man/cat1/sleep.0

SLEEP(1)                     BSD Reference Manual                     SLEEP(1)

NNAAMMEE
     sslleeeepp - suspend execution for an interval of time

SSYYNNOOPPSSIISS
     sslleeeepp _s_e_c_o_n_d_s

DDEESSCCRRIIPPTTIIOONN
     The sslleeeepp command suspends execution for a minimum of _s_e_c_o_n_d_s. SSlleeeepp is
     used to schedule the execution of other commands (see _E_X_A_M_P_L_E_S below).

     The SSlleeeepp utility exits with one of the following values:

     0     On successful completetion, or if the signal SIGALRM was received.

     >0    An error occurred.

EEXXAAMMPPLLEESS
     To schedule the execution of a command for _x number seconds later:

           (sleep 1800; sh command_file >& errors)&

     This incantation would wait a half hour before running the script com-
     mand_file. (See the at(1) utility.)

     To reiteratively run a command (with the csh(1)):

           while (1)
                   if (! -r zzz.rawdata) then
                           sleep 300
                   else
                           foreach i (`ls *.rawdata`)
                                   sleep 70
                                   awk -f collapse_data $i >> results
                           end
                           break
                   endif
           end

     The scenario for a script such as this might be: a program currently run-
     ning is taking longer than expected to process a series of files, and it
     would be nice to have another program start processing the files created
     by the first program as soon as it is finished (when zzz.rawdata is cre-
     ated).  The script checks every five minutes for the file zzz.rawdata,
     when the file is found, then another portion processing is done curteous-
     ly by sleeping for 70 seconds in between each awk job.

SSEEEE AALLSSOO
     setitimer(2),  alarm(3),  sleep(3),  at(1)

SSTTAANNDDAARRDDSS
     The sslleeeepp command is expected to be IEEE Std1003.2 (``POSIX'') compati-
     ble.

4.4BSD                           May 31, 1993                                1