linux安全检测及防护,linux安全检测及防护-单选题（Linux security detection and protection）.doc...

linux安全检测及防护-单选题(Linux security detection and protection).doc

linux安全检测及防护-单选题(Linux security detection and protection)===<<< RadioButtonList >>>===

1. the correct description of the standard input and output is [() [selection of 1 items]

The file number of A. stdin is 0, and the default device is the keyboard

The file number of B. stdin is 1, and the default device is the keyboard

The file number of C. stderr is 1, and the default device is the monitor

The file number of D. stdout is 2, and the default device is the monitor

2. about single quotation marks and double quotation marks, the correct description is () [select 1 items]

A. single quotes can refer to the value of a variable

B. double quotes can't refer to variable values inside

There is no difference between C. single quotes and double quotes, and the effect is the same in the process of variable reference

D. double quotes can refer to the value of a variable

3. the function of the reverse quotation is [() [select 1 items]

A. is in quotation marks to refer to the value of a variable

B. is in reverse quote to define variables for special characters

C. is in reverse quotation marks to change the result of a command to the value of a variable

D. is in quotation marks to refer to variables under the sub shell

The function of 4. braces {} is [()] [1 items]

A. to distinguish the values of the local variables and the environment variables, B. is used to distinguish the variable values from the ordinary characters

C.__ in order to refer to the result of a special command as a variable value D., in order to change the local variable into the environment variable

5. use Bash and. When you execute scripts, the difference between the two ways is () [choosing 1 items]

There is no difference between A. and the script file can be executed later

B. bash will execute the following script file in the current shell environment

C.. The script file will be executed in the current shell environment

D. uses bash to execute scripts that require permission to set X for script files

6. which