有没有人知道在Fortran中以一定的毫秒数睡眠的方法？我不想使用非便携式系统调用，因此Fortran或C库固有的任何内容都是首选。
有没有人知道在Fortran中以一定的毫秒数睡眠的方法？我不想使用非便携式系统调用，因此Fortran或C库固有的任何内容都是首选。
使用Fortran ISO C绑定使用C库睡眠以秒为单位进行睡眠：
module Fortran_Sleep
use, intrinsic :: iso_c_binding, only: c_int
implicit none
interface
! should be unsigned int ... not available in Fortran
! OK until highest bit gets set.
function FortSleep (seconds) bind ( C, name="sleep" )
import
integer (c_int) :: FortSleep
integer (c_int), intent (in), VALUE :: seconds
end function FortSleep
end interface
end module Fortran_Sleep
program test_Fortran_Sleep
use, intrinsic :: iso_c_binding, only: c_int
use Fortran_Sleep
implicit none
integer (c_int) :: wait_sec, how_long
write (*, '( "Input sleep time: " )', advance='no')
read (*, *) wait_sec
how_long = FortSleep ( wait_sec )
write (*, *) how_long
stop
end program test_Fortran_Sleep
您可以使用Fortran标准内部函数来执行此操作而无需C绑定：
program sleep
!===============================================================================
implicit none
character(len=100) :: arg ! input argument character string
integer,dimension(8) :: t ! arguments for date_and_time
integer :: s1,s2,ms1,ms2 ! start and end times [ms]
real :: dt ! desired sleep interval [ms]
!===============================================================================
! Get start time:
call date_and_time(values=t)
ms1=(t(5)*3600+t(6)*60+t(7))*1000+t(8)
! Get the command argument, e.g. sleep time in milliseconds:
call get_command_argument(number=1,value=arg)
read(unit=arg,fmt=*)dt
do ! check time:
call date_and_time(values=t)
ms2=(t(5)*3600+t(6)*60+t(7))*1000+t(8)
if(ms2-ms1>=dt)exit
enddo
!===============================================================================
endprogram sleep
假设可执行文件是slp：
~$ time slp 1234
real 0m1.237s
user 0m1.233s
sys 0m0.003s
如果您担心它会在午夜时分破坏，请在此程序中添加一个特殊情况:)
! This is another option of making your fortran code to wait for x seconds
Integer :: iStart, iNew
Real*8 :: rWait, rDT
! rWait: seconds that you want to wait for; you can also set this as an (IN)
! variable if this code goes into a subroutine that is developed to be called
! from any part of the program.
rWait = 1.d0; rDT = 0.d0
call system_clock (iStart)
do while (rDT <= rWait)
call system_clock (iNew)
rDT = floatj (iNew - iStart) / 10000.d0
enddo