60 lines
2.8 KiB
Markdown
60 lines
2.8 KiB
Markdown
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# The `touch` Command
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The `touch` command modifies a file's timestamps. If the file specified doesn't exist, an empty file with that name is created.
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### Syntax
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```
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touch [OPTION]... FILE...
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```
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### Options
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|**Short Flag** |**Long Flag** |**Description** |
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|:---|:---|:---|
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|`-a`|<center>-</center>|Change only the access time.|
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|`-c`|`--no-create`|Do not create any files.|
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|`-d` STRING|`--date=STRING`|Parse *STRING* and use it instead of the current time.|
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|`-f`|<center>-</center>|(Ignored) This option does nothing but is accepted to provide compatibility with BSD versions of the `touch` command.|
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|`-h`|`--no-dereference`|Affect each symbolic link instead of any referenced file (useful only on systems that can change the timestamps of a symlink). This option implies `-c`, nothing is created if the file does not exist.|
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|`-m`|<center>-</center>|Change only the modification time.|
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|`-r=FILE`|`--reference=FILE`|Use this file's times instead of the current time.|
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|`-t STAMP`|<center>-</center>|Use the numeric time *STAMP* instead of the current time. The format of *STAMP* is [[**CC**]**YY**]**MMDDhhmm**[**.ss**].|
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|<center>-</center>|`--time=WORD`|An alternate way to specify which type of time is set (e.g. *access*, *modification*, or *change*). This is equivalent to specifying `-a` or `-m`.
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- WORD is `access`, `atime`, or `use`: equivalent to `-a`.
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- WORD is `modify` or `mtime`: equivalent to `-m`.
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An alternate way to specify what type of time to set (as with **-a** and **-m**).|
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|<center>-</center>|`--help`|Display a help message, and exit.|
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|<center>-</center>|`--version`|Display version information, and exit.|
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### Examples
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1. If **file.txt** exists, set all of its timestamps to the current system time. If **file.txt** doesn't exist, create an empty file with that name.
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```
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touch file.txt
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```
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2. If **file.txt** exists, set its times to the current system time. If it does not exist, do nothing.
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```
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touch -c file.txt
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```
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3. Change the *access* time of **file.txt**. The *modification* time is not changed. The *change* time is set to the current system time. If **file.txt** does not exist, it is created.
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```
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touch -a file.txt
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```
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4. Change the times of file **symboliclink**. If it's a symbolic link, change the times of the symlink, ***NOT*** the times of the referenced file.
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```
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touch -h symboliclink
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```
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5. Change the *access* and *modification* times of **file-b.txt** to match the times of **file-a.txt**. The *change* time will be set to the current system time. If **file-b.txt** does not exist, it is not created. Note, **file-a.txt** must already exist in this context.
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```
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touch -cr file-a.txt file-b.txt
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```
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6. Set the *access* time and *modification* time of **file.txt** to ***February 1st*** of the current year. The *change* time is set to the current system time.
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```
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touch -d "1 Feb" file.txt
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```
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