June 4, 1993 SLEEP 3

### NAME

sleep - suspend process execution for interval of seconds

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```unsigned` `int` sleep(```unsigned int seconds`)

### DESCRIPTION

The sleep(``) function suspends execution of the calling process until either the number of seconds specified by ```seconds` have elapsed or a signal is delivered to the calling process and its action is to invoke a signal-catching function or to terminate the process. The suspension time may be longer than requested due to the scheduling of other activity by the system.

### RETURN VALUES

If the sleep(``) function returns because the requested time has elapsed, the value returned will be zero. If the sleep(``) function returns due to the delivery of a signal, the value returned will be the unslept amount (the request time minus the time actually slept) in seconds.

### SEE ALSO

nanosleep(2), usleep(3)

### STANDARDS

The sleep(``) function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'') .

### HISTORY

A sleep(``) function appeared in Version 7 `AT&T UNIX`.