Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

sleep(3) [linux man page]

SLEEP(3)						     Linux Programmer's Manual							  SLEEP(3)

sleep - Sleep for the specified number of seconds SYNOPSIS
#include <unistd.h> unsigned int sleep(unsigned int seconds); DESCRIPTION
sleep() makes the calling thread sleep until seconds seconds have elapsed or a signal arrives which is not ignored. RETURN VALUE
Zero if the requested time has elapsed, or the number of seconds left to sleep, if the call was interrupted by a signal handler. CONFORMING TO
POSIX.1-2001. BUGS
sleep() may be implemented using SIGALRM; mixing calls to alarm(2) and sleep() is a bad idea. Using longjmp(3) from a signal handler or modifying the handling of SIGALRM while sleeping will cause undefined results. SEE ALSO
alarm(2), nanosleep(2), signal(2), signal(7) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at GNU
2010-02-03 SLEEP(3)

Check Out this Related Man Page

ALARM(2)						     Linux Programmer's Manual							  ALARM(2)

alarm - set an alarm clock for delivery of a signal SYNOPSIS
#include <unistd.h> unsigned int alarm(unsigned int seconds); DESCRIPTION
alarm() arranges for a SIGALRM signal to be delivered to the calling process in seconds seconds. If seconds is zero, no new alarm() is scheduled. In any event any previously set alarm() is canceled. RETURN VALUE
alarm() returns the number of seconds remaining until any previously scheduled alarm was due to be delivered, or zero if there was no pre- viously scheduled alarm. CONFORMING TO
SVr4, POSIX.1-2001, 4.3BSD. NOTES
alarm() and setitimer(2) share the same timer; calls to one will interfere with use of the other. sleep(3) may be implemented using SIGALRM; mixing calls to alarm() and sleep(3) is a bad idea. Scheduling delays can, as ever, cause the execution of the process to be delayed by an arbitrary amount of time. SEE ALSO
gettimeofday(2), pause(2), select(2), setitimer(2), sigaction(2), signal(2), sleep(3), time(7) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at Linux 2008-06-12 ALARM(2)
Man Page

15 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers


I have a Solaris 2.6 machine and I execute the following: while do echo looping sleep 15 done I would assume the looping would be printed every 15 seconds but it doesn't. consecutive looping gets printed without a 15 second gap. Any idea what might be the reason ? Thanks (9 Replies)
Discussion started by: brv
9 Replies

2. Shell Programming and Scripting

Sleep under one second

If I want a script to sleep for less than a second, would I use a decimal? In other words, if I wanted my script to sleep for 1/4 of a second, would I say, SLEEP .25 ?? (5 Replies)
Discussion started by: Scoogie
5 Replies

3. Programming

generating timer

I'm trying generate an interrupt every 1 seconds using itimer and My clock is not running. This is what i did : printf("about to sleep for 1 second \n"); signal(SIGALRM, wakeup); //myTimer.it_interval.tv_sec=0; //myTimer.it_interval.tv_usec =0; ... (5 Replies)
Discussion started by: Confuse
5 Replies

4. UNIX for Dummies Questions & Answers

Sleep less than 1 second

Does anyone know a way to sleep less than 1 second? Sometimes when I write scripts that iterates a loop many times it would be nice to slow things down, but sometimes 1 second is too much. (9 Replies)
Discussion started by: bjorno
9 Replies

5. Programming

signal handling question

Hello all, I am starting to learn signal handling in Linux and have been trying out some simple codes to deal with SIGALRM. The code shown below sets a timer to count down. When the timer is finished a SIGALRM is produced. The handler for the signal just increments a variable called count. This... (7 Replies)
Discussion started by: fox_hound_33
7 Replies

6. Shell Programming and Scripting

search for a file, if not found sleep and repeat it for 3 hrs

Hi, Can someone help me with this script .... I need a ksh script, which will search for a specific file in a directory, if file not found sleep for 10 mins and search again, if still not found sleep again for 10 mins and so on .... it should search for that file for 3 hours and if that file... (5 Replies)
Discussion started by: santosham
5 Replies

7. UNIX for Dummies Questions & Answers

sleep 10 && command doesn't work

Hi there, I found a trick to easily postpone a command by a few seconds: supernova:~# sleep 10 && command &If you logout, the command should still be executed... But not all the time. Could anyone of you explain me why the following command is executed even after logging out: supernova:~# sleep... (2 Replies)
Discussion started by: chebarbudo
2 Replies

8. Programming

RDTSC use in C:

I have to use rdtsc on ubuntu for performance evaluation. But i am not getting the correct value. I am placing a sleep on 10 seconds, but value i get is some 1 sec... i dont know where im going wrong? #include<sys/time.h> #include<time.h> #include<stdio.h> typedef unsigned long long ticks; ... (8 Replies)
Discussion started by: GloriousDaisy
8 Replies

9. UNIX for Dummies Questions & Answers

select first column of file

Hi, Following is my file output 247 Sleep 25439 NULL 259 Sleep 25460 NULL 277 Sleep 15274 NULL 361 Sleep 2 NULL 362 Sleep 202 NULL I want to select only first column to other file How can... (2 Replies)
Discussion started by: kaushik02018
2 Replies

10. Programming

Unix Shell background processing

So I made my own unix shell, but i want to make a background process when using the & appended to the end, so far most of the commands seem to work (except cd, but thats another story) right now here is what I have got. Im thinking maybe I shouldn't be using switch and maybe switch it to... (27 Replies)
Discussion started by: Mercfh
27 Replies

11. UNIX for Dummies Questions & Answers

sleep command off by a second

Hi Forum Im using sleep in a while loop goes around 10 times. i feed it a variable with the time i what it to sleep for eg sleep $sleepVal and then print system date and time to screen but sometimes 1 second is added to the time why is this here my code sleepVal=5 while do ... (3 Replies)
Discussion started by: ShinTec
3 Replies

12. Shell Programming and Scripting

How the Sleep function will work?

Hi All, I am new to Unix , there i am facing one problem with sleep command. that is .. in while loop i have defined sleep function .. my condition is like this while #i knew this is infinite loop do sleep 200 echo "hello " done. this condition will never become .. true... (3 Replies)
Discussion started by: mandlysreedhar
3 Replies

13. UNIX for Dummies Questions & Answers

Sleep command not sleeping for specified time.

Hi, I have ascript with a recursive funtion below. I have mentioned to sleep for 60minutes but it doesnt doing so. Its keep on running until if /elif conditions satiesfies. Can you pls help what is wrong here. funcstatus () { if then echo "`date` - Current status... (2 Replies)
Discussion started by: gaddamja
2 Replies

14. Programming

How to sleep and wake a thread???

Hi guys, I am creating two posix threads. I have some queries, hopefully you will help me out with them 1) How can I put a thread to indefinite sleep, for indefinite time period. I am familiar with this sleep(5); for 5 second, how can I make it indefinite?? 2) How can one thread wake another... (11 Replies)
Discussion started by: gabam
11 Replies

15. UNIX for Dummies Questions & Answers

Sleep Until Query

Hi, I am a newbie in UNIX please help me develop code for below logic:-- I want my script to implement sleep until a specified time(date doesn't matter) ---------------------------------------- While currenttime > 14:00 and < 18:00 sleep end while run command exit... (9 Replies)
Discussion started by: kiitmale
9 Replies