SLEEP(1) UNIX 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 EXAMPLES 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 command_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 created). 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 sleep function is expected to be POSIX 1003.2 compatible.