Fish:
在 4NT 下找到内部命令 DELAY
[阅读: 593] 2005-03-02 08:28:52
DELAY
Purpose: Pause for a specified length of time.
Format: DELAY [/B /M time]
time: The number of seconds or milliseconds to delay.
/B(reak enabled) /M(illiseconds)
Usage
DELAY is useful in batch file loops while waiting for something to occur. To wait for 10 seconds:
delay 10
DELAY is most useful when you need to wait a specific amount of time for an external event, or check a system condition periodically. For example, this batch file checks the battery status (as reported by your Advanced Power Management drivers) every 15 seconds, and gives a warning when battery life falls below 30%:
do forever
iff %_apmlife lt 30 then
beep 440 4 880 4 440 4 880 4
echo Low Battery!!
endiff
delay 15
enddo
The seconds value can be as large as about 1 billion seconds (34 years!).
4NT uses the minimum possible processor time during a DELAY, in order to allow other applications full use of system resources.
You can cancel a delay by pressing Ctrl-C or Ctrl-Break.
Options
/B (Break) Allows terminating a DELAY by pressing a key.
/M (Milliseconds) Count by milliseconds instead of seconds. Normally only used for delays of less than 1 second.