Checks the permission of a file or a directory
Checks the permission of a file or a directory.
## Default S3 method: fileAccess(pathname, mode=0, safe=TRUE, ...)
pathname |
A |
mode |
An |
safe |
If |
... |
Not used. |
In R there is file.access() for checking whether the
permission of a file.
Unfortunately, that function cannot be 100% trusted depending on
platform used and file system queried, cf. [1].
Returns an integer; 0 if the permission exists, -1 if not.
This function follows symbolic links (also on Windows) and returns a value based on the link target (rather than the link itself).
Henrik Bengtsson
[1] R-devel thread
file.access() on network (mounted) drive on Windows Vista?
on Nov 26, 2008.
https://stat.ethz.ch/pipermail/r-devel/2008-December/051461.html
[2] Filesystem permissions, Wikipedia, 2010.
https://en.wikipedia.org/wiki/Filesystem_permissions
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# Current directory
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path <- "."
# Test for existence
print(fileAccess(path, mode=0))
# Test for execute permission
print(fileAccess(path, mode=1))
# Test for write permission
print(fileAccess(path, mode=2))
# Test for read permission
print(fileAccess(path, mode=4))
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# A temporary file
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pathname <- tempfile()
cat(file=pathname, "Hello world!")
# Test for existence
print(fileAccess(pathname, mode=0))
# Test for execute permission
print(fileAccess(pathname, mode=1))
# Test for write permission
print(fileAccess(pathname, mode=2))
# Test for read permission
print(fileAccess(pathname, mode=4))
file.remove(pathname)
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# The 'base' package directory
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path <- system.file(package="base")
# Test for existence
print(fileAccess(path, mode=0))
# Test for execute permission
print(fileAccess(path, mode=1))
# Test for write permission
print(fileAccess(path, mode=2))
# Test for read permission
print(fileAccess(path, mode=4))
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# The 'base' package DESCRIPTION file
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pathname <- system.file("DESCRIPTION", package="base")
# Test for existence
print(fileAccess(pathname, mode=0))
# Test for execute permission
print(fileAccess(pathname, mode=1))
# Test for write permission
print(fileAccess(pathname, mode=2))
# Test for read permission
print(fileAccess(pathname, mode=4))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.