unlink fails to remove symbolic links

unlink fails to remove symbolic links. This is more prominent now --
when a package creates symbolic links during installation, 00LOCK is
not removed.

Martin

setwd(tempdir())
fl <- tempfile(); file.create(fl)

[1] TRUE

lnFile <- tempfile(); system(paste("ln -s", fl, lnFile))
list.files()

[1] "file19495cff" "file74b0dc51"

unlink(fl); unlink(lnFile)
list.files()

[1] "file19495cff"

lnFile

[1] "/tmp/Rtmpb0kd7B/file19495cff"

sessionInfo()

R version 2.10.0 Under development (unstable) (2009-03-21 r48173)
x86_64-unknown-linux-gnu

locale:
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-\
8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] tools_2.10.0

A little more precisely, unlink fails when the file being unlinked is
a broken symbolic link (as in the example below). This is because
R_FileExists checks stat() == 0, and stat fails (returns -1) when
trying to resolve the broken link. Perhaps lstat() is more
appropriate?

Martin

Martin Morgan <mtmorgan at fhcrc.org> writes:

unlink fails to remove symbolic links. This is more prominent now --
when a package creates symbolic links during installation, 00LOCK is
not removed.

Martin

setwd(tempdir())
fl <- tempfile(); file.create(fl)

[1] TRUE

lnFile <- tempfile(); system(paste("ln -s", fl, lnFile))
list.files()

[1] "file19495cff" "file74b0dc51"

unlink(fl); unlink(lnFile)
list.files()

[1] "file19495cff"

lnFile

[1] "/tmp/Rtmpb0kd7B/file19495cff"

sessionInfo()

R version 2.10.0 Under development (unstable) (2009-03-21 r48173)
x86_64-unknown-linux-gnu

locale:
LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-\
8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] tools_2.10.0

-- 
Martin Morgan
Computational Biology / Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N.
PO Box 19024 Seattle, WA 98109

Location: Arnold Building M2 B169
Phone: (206) 667-2793