Linux commands (4): Touch

Function Description:

The Touch command parameter creates a new file and changes the date and time of the document or directory, including access time and change time.

Command format:

touch [Options] ... File...

Command parameters:

-A or--time=atime or--time=access or--time=use only change the access time.

-C or--no-create does not establish any documents.

-D uses the specified date time instead of the current time.

-F This parameter ignores non-processing and is responsible only for compatibility issues with BSD version touch directives.

-M or--time=mtime or--time=modify only change the change time.

-R Sets the date and time of the specified document or directory to the same date and time as the reference document or directory.

-T uses the specified date time instead of the current time.

Command case:

Case 1, create a new file

[email protected] miao]# Touch a.txt B.log
[email protected] miao]# LL
Total 0
-rw-r--r--1 root root 0 7 17:01 a.txt
-rw-r--r--1 root root 0 7 17:01 B.log
[Email protected] miao]#

Case 2, Update a.txt time and B.log timestamp are the same

[email protected] miao]# LL
Total 0
-rw-r--r--1 root root 0 7 17:06 A.log
-rw-r--r--1 root root 0 7 17:01 a.txt
-rw-r--r--1 root root 0 7 17:01 B.log
[Email protected] miao]# touch-r a.txt a.log
[email protected] miao]# LL
Total 0
-rw-r--r--1 root root 0 7 17:01 A.log
-rw-r--r--1 root root 0 7 17:01 a.txt
-rw-r--r--1 root root 0 7 17:01 B.log
[Email protected] miao]#

Case 3, set the timestamp of the file

[Email protected] miao]# touch-t 201408010000.00 a.log
[email protected] miao]# LL
Total 0
-rw-r--r--1 root root 0 1 00:00 a.log
-rw-r--r--1 root root 0 7 17:01 a.txt
-rw-r--r--1 root root 0 7 17:01 B.log
[Email protected] miao]#

Description: The time specified here is a decimal number in the following form: [[cc]yy]mmddhhmm[]. SS] Due to system limitations, the time earlier than January 1, 1970 was wrong.