echo $?回传值的意思

echo $?回传值的意思：

• 0 program is running or service is OK
• 1 program is dead and /var/run pid file exists
• 2 program is dead and /var/lock lock file exists
• 3 program is not running
• 4 program or service status is unknown
• 5-99 reserved for future LSB use
• 100-149 reserved for distribution use
• 150-199 reserved for application use
• 200-254 reserved