diff options
Diffstat (limited to 'bin/sleep/sleep.1')
| -rw-r--r-- | bin/sleep/sleep.1 | 84 |
1 files changed, 46 insertions, 38 deletions
diff --git a/bin/sleep/sleep.1 b/bin/sleep/sleep.1 index 924bc732a0d0..c9069a015706 100644 --- a/bin/sleep/sleep.1 +++ b/bin/sleep/sleep.1 @@ -29,10 +29,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" @(#)sleep.1 8.3 (Berkeley) 4/18/94 -.\" $FreeBSD$ -.\" -.Dd December 31, 2020 +.Dd March 22, 2024 .Dt SLEEP 1 .Os .Sh NAME @@ -40,13 +37,27 @@ .Nd suspend execution for an interval of time .Sh SYNOPSIS .Nm -.Ar seconds +.Ar number Ns Op Ar unit +.Op ... .Sh DESCRIPTION The .Nm -command -suspends execution for a minimum of -.Ar seconds . +command suspends execution for a minimum of +.Ar number +seconds (the default, or unit +.Li s ) , +minutes (unit +.Li m ) , +hours (unit +.Li h ) , +or days (unit +.Li d ) . +Intervals can be written in any form allowed by +.Xr strtod 3 . +If multiple intervals are given, they are added together. +If the final sum is zero or negative, +.Nm +exits immediately. .Pp If the .Nm @@ -59,56 +70,49 @@ sleep is printed on the standard output. The .Dv SIGALRM signal is not handled specially by this implementation. -.Pp -The -.Nm -command allows and honors a non-integer number of seconds to sleep -in any form acceptable by -.Xr strtod 3 . -This is a non-portable extension, but is also implemented in GNU sh-utils -since version 2.0a (released in 2002). .Sh EXIT STATUS .Ex -std .Sh EXAMPLES -To schedule the execution of a command for -.Va x -number seconds later (with -.Xr csh 1 ) : +To run a command after half an hour: .Pp -.Dl (sleep 1800; sh command_file >& errors)& +.Dl (sleep 0.5h; sh command_file >out 2>err)& .Pp -This incantation would wait a half hour before -running the script command_file. -(See the +This incantation would wait half an hour before +running the script +.Pa command_file . +See the .Xr at 1 -utility.) +utility for another way to do this. .Pp -To reiteratively run a command (with the -.Xr csh 1 ) : +To reiteratively run a command: .Pp .Bd -literal -offset indent -compact -while (1) - if (! -r zzz.rawdata) then - sleep 300 +while :; do + if ! [ -r zzz.rawdata ] ; then + sleep 5m else - foreach i (`ls *.rawdata`) + for i in *.rawdata ; do sleep 70 - awk -f collapse_data $i >> results - end + awk -f collapse_data "$i" + done >results break - endif -end + fi +done .Ed .Pp The scenario for a script such as this might be: a program currently running 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, +program as soon as it is finished (when +.Pa zzz.rawdata +is created). +The script checks every five minutes for the file +.Pa zzz.rawdata , when the file is found, then another portion processing is done courteously by sleeping for 70 seconds in between each -awk job. +.Xr awk 1 +job. .Sh SEE ALSO .Xr nanosleep 2 , .Xr sleep 3 @@ -118,6 +122,10 @@ The command is expected to be .St -p1003.2 compatible. +.Pp +Support for non-integer intervals, units other than seconds, and +multiple intervals which are added together are non-portable +extensions first introduced in GNU sh-utils 2.0a (released in 2002). .Sh HISTORY A .Nm |