![]() ![]() nodiratime (no dir atime): This option enables access timestamps for files to update, but disables it for directories.The modified timestamps, however, will still update. noatime (no atime): This option fully disables the access timestamps for files and directories from updating.It has little merit on a desktop or laptop computer. There’s an overhead attached with this approach, but some servers can benefit from this scheme. strictatime (strict atime): This option updates the access timestamp of files every time they’re accessed.The following are some of the most common options: You can also set options to dictate the scheme they should use to update the access timestamp. These are stored in the /etc/fstab file, which is read and processed at boot time. When a file system is mounted, there are options you can use to specify how that file system should operate or be treated. RELATED: How to Use the chmod Command on Linux How the File System Updates Timestamps However, the metadata about the file was changed. This is because the file itself wasn’t changed-it was neither accessed nor modified. The changed timestamp was the only one that updated. It also ensures the month is in the correct language. The location and time zone the computer viewing the file is in guides the conversion of the number of seconds to a date and time. This makes it easier for humans to understand. When Linux needs to display a timestamp, it translates the number of seconds into a date and time. Leap seconds are ignored in Linux timestamps, so they aren’t analogous to real time. This number is the number of seconds since the Unix epoch, which was midnight (00:00:00) on January 1, 1970, in Coordinated Universal Time (UTC). Linux timestamps hold a number rather than a date and time. Sometimes, this timestamp is populated, but you can’t depend on the values in it. The standard ext4 Linux file system also allocates space for a file-creation timestamp in its internal file system structures, but this hasn’t been implemented yet. File permission changes, for example, will update the changed timestamp. Rather, it’s the time at which the metadata related to the file was changed. “Modified” means something inside the file was amended or deleted, or new data was added.Ĭhanged timestamps aren’t referring to changes made to the contents of a file. A program or process either edited or manipulated the file. $ touch a.txt -r tgs.A modified timestamp signifies the last time the contents of a file were modified. The following touch command example will update the time-stamp of file a.txt with the time-stamp of tgs.txt file. You can also take a file as a reference, and update the time for other files, so that both file will hold the same time. Copy the Time-stamp from Another File using -r You can also use a string to change the timeĪnother example: $ touch -d " 12:12:12.000000000 +0530" tgs.txtįor developers, touch command will be really helpful when you are working with Makefiles 5. Size: 3 Blocks: 8 IO Block: 4096 regular file Verify the above change using stat command: $ stat tgs.txt It is not possible to set the date beyond January 18, 2038.įor example: $ touch -a -m -t 203801181205.09 tgs.txt If the value of the YY is between 00 and 37, the value of the CC digits is assumed to be 20. If the value of the YY is between 70 and 99, the value of the CC digits is assumed to be 19. YY – Specifies the last two digits of the year.CC – Specifies the first two digits of the year.The format for specifying -t is YY]MMDDhhmm Instead of taking the current time-stamp, you can explicitly specify the time using -t and -d options. Explicitly Setting Access and Modification time using -t and -d NOTE: It is not possible to change the ctime using touch command 4. ![]() The above method can be used to change the mtime of all obj files, when using make utility. ![]() You can change the modification time of a file using -m option. By default it will take the current system time and update the atime field.īefore touch command is executed: $ stat tgs.txt We can change the access time of a file using -a option. ![]()
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