Sleep/usleep__oracle of delay function in Linux_shell_linux

The latency in the Linux shell script is still using the sleep or Usleep function.

Detailed as follows: 1, sleep: default is seconds.
Sleep 1s indicates a second delay
Sleep 1m indicates a minute delay
Sleep 1h indicates a delay of one hour
Sleep 1d indicates a day delay

2, Usleep: Default to microseconds.

1s = 1000ms = 1000000us

Difference: Sleep can specify not only the seconds, but also the deferred units, for example:

Sleep 1s indicates a second delay
Sleep 1m indicates a minute delay
Sleep 1h indicates a delay of one hour
Sleep 1d indicates a day delay