[Rd] Sys.readlink (on BSD vs Linux)

[Sven E. Templer]

Hello together,

the function `Sys.readlink` uses the system's readlink command to resolve symlink paths. On OSX/BSD the command has a different meaning than on Linux [1].

There exists the tool 'realpath', which seems suitable for the task, at least applied at the command line level [2]. It is used in `normalizePath`.

I suggest (at least the latter) to
* use realpath instead readlink within Sys.readlink (do_readlink -> do_normalizepath)
* link to `normalizePath` in the Rd document, eventually mentioning the difference

Many thanks,
Sven

[1] see
https://www.freebsd.org/cgi/man.cgi?query=readlink
vs
http://linux.die.net/man/1/readlink

[2]
https://www.freebsd.org/cgi/man.cgi?query=realpath
http://linux.die.net/man/1/realpath


---------------------------

Sven E. Templer
Bioinformatics Core Group

Max Planck Institute for Biology of Ageing
Joseph-Stelzmann-Strasse 9b
50931 Cologne, Germany

Phone: 0049 (0)221 37970 325
templer at age.mpg.de
http://www.age.mpg.de/the-science/core-facilities/bioinformatics/