Touch Modify Timestamp ( often used to create empty files )
1 , command format
Touch [Options]file ...
2 , command functions
used to modify the file timestamp, access time, modification time, change time, if any parameters are not added by default create an empty file
Linux file time stamp (timestamp) :
Access time: Last accessed ( read ) access
Modified: Write Data modify Change the contents of the file
Span style= "font-family: ' Times New Roman ', Serif;color: #333333; background: #FFFFFF;" > ( ) Change metadata properties of changed files
Change time will change automatically, change time will change when the file is accessed, or when the contents of the file are modified
3 , common options
-A : Modify the file access time for the current time, if and - T can be modified to a specified time
- C : Do not create an empty file if the file does not exist
- H : Modification is the timestamp of the linked file rather than the original file
- M : Modify the modification time
- T : modified to the specified time instead of the current time ; [[Cc]yy] MMDDHHMM[.SS]
- R : Timestamp of the current file using the timestamp of the specified file
4 , use instances
1. Create an empty file
command: Touch File
[[Email protected]~]# lsinittab test Test.tar.gz[[email protected]~]# Touch new[[email protected]~]# lsinittab New test Test.tar.gz[[email protected]~]#
2 , modify the file's access time to the current time
command: touch-a File
[[email protected]~]# stat new file: ' new ' Size: 0 Blocks:0 IO Block: 4096 regular empty Filedevice:fd01h/64769d inode: 527572 links: 1access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) access:2016-12-21 10:39:03.988012456 +0800modify:2016-12-21 10:39:03.988012456 +0800change:2016-12-21 10:39:03.988012456 +0800[[email protected]~]# touch -a new [[email protected]~]# stat new file: ' new ' Size: 0 blocks:0 io block: 4096 regular empty filedevice:fd01h/64769d inode: 527572 links: 1access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ Root) access:2016-12-21 10:40:26.673996182 +0800modify:2016-12-21 10:39:03.988012456 + 0800change:2016-12-21 10:40:26.673996182 +0800[[email protected]~]#
3 , the update file timestamp is the same as another file
command: touch-r File1 File2
[[email protected]~]# stat test file: ' Test ' Size: 8 Blocks:8 io block: 4096 regular filedevice: Fd01h/64769d inode: 527575 links: 1access :(0644/-rw-r--r--) Uid: ( 0/ root) gid: ( 0/ root) access: 2016-12-21 10:30:40.233999427 +0800modify:2016-12-20 09:54:30.885994856 +0800change: 2016-12-21 10:30:40.233999427 +0800[[email protected]~]# touch -r test new [[email protected] ~]# stat test file: ' Test ' Size: 8 blocks:8 io block: 4096 regular filedevice:fd01h/64769d inode: 527575 links: 1access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) access:2016-12-21 10:30:40.233999427 +0800modify:2016-12-20 09:54:30.885994856 +0800change:2016-12-21 10:41:59.919007361 +0800
4 , modify the Access file time stamp to the specified time
command: Touch-at [[CC]YY]MMDDHHMM[.SS] File ...
[[email protected]~]# touch -at 1612121212 new test[[email protected]~]# stat new File: ' new ' size: 0 Blocks:0 io block: 4096 regular empty fileDevice:fd01h/64769d Inode: 527572 Links: 1access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) access:2016-12-12 12:12:00.000000000 +0800modify:2016-12-21 10:14:42.864999624 +0800change:2016-12-21 10:48:16.047994796 +0800
Description
- T time Use the specified time value
Time the new value that is the corresponding time stamp for the specified file. The time specified here is a decimal number in the following form :
[[Cc]yy] mmddhhmm[. SS]
CC for the first two digits of the number of years, YY for the latter two digits of the number of years;
If you do not give the CC the value
the Touch The number of years will be set as the year of the current system;
MM is the number of months, DD is the number of days,
hh is the number of hours ( time ) ,
mm is the number of minutes,
SS is the number of seconds.
Stat Displays the timestamp of the file
command: Stat File ...
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One day a linux base command modified file timestamp touch