R: Updates the timestamp of a file

touchFile {R.utils} | R Documentation

## Updates the timestamp of a file

### Description

Updates the timestamp of a file. Currently, it is only possible to change the timestamp specifying when the file was last modified, and time can only be set to the current time.

### Usage

    ## Default S3 method:
    touchFile(pathname, ...)

### Arguments

`pathname` | A `character` `vector` specifying files to be updated.
`...` | Not used.

### Value

Returns (invisibly) a `vector` of the old timestamps.

### Author(s)

Henrik Bengtsson

### References

[1] R-devel mailing list thread Unix-like touch to update modification timestamp of file?, started on 2008-02-26. http://stat.ethz.ch/pipermail/r-devel/2008-February/048542.html

### See Also

Internally, `Sys.setFileTime`() (iff available) and `file.info`() are utilized.

### Examples

    # 1. Create a file
    pathname <- tempfile()
    cat(file=pathname, "Hello world!")
    md5a <- digest::digest(pathname, file=TRUE)

    # 2. Current time stamp
    ta <- file.info(pathname)$mtime
    print(ta)

    # 3. Update time stamp
    Sys.sleep(1.2)
    touchFile(pathname)
    tb <- file.info(pathname)$mtime
    print(tb)

    # 4. Verify that the timestamp got updated
    stopifnot(tb > ta)

    # 5. Verify that the contents did not change
    md5b <- digest::digest(pathname, file=TRUE)
    stopifnot(identical(md5a, md5b))

[Package R.utils version 2.7.0 Index]