Sys.which {base} | R Documentation |
This is an interface to the system command which
.
Sys.which(names)
names |
Character vector of names of possible executables. |
The system command which
reports on the full names of an
executable (including an executable script) found on the current path.
On Windows an ‘executable’ is a file with extension
‘.exe’, ‘.com’, ‘.cmd’ or ‘.bat’. Such files need
not actually be executable, but they are what system
tries.
On a Unix-alike the full path to which
(usually
‘/usr/bin/which’) is found when R is installed and (currently)
stored in environment variable WHICH
.
A character vector of the same length as names
, named by
names
. The elements are either the full path to the
executable or some indication that no executable of that name was
found. Typically the indication is ""
, but this does depend on
the OS (and the known exceptions are changed to ""
).
## the first two are likely to exist everywhere ## texi2dvi exists on most Unix-alikes and under MiKTeX Sys.which(c("ftp", "ping", "texi2dvi", "this-does-not-exist"))