Files
The function FileExists checks whether a file or a lock-file
exists
The function LockRemove removes a lock-file
FileExists(file, printlevel=RFoptions()$basic$printlevel) LockFile(file, printlevel=RFoptions()$basic$printlevel) LockRemove(file)
file |
name of the data file |
printlevel |
if |
FileExists checks whether file or file.lock exists.
If none of them exists file.lock is created and hostname and
PID are written into file.lock. This is useful if several processes
use the same directory. Further, it is checked whether another process
has tried to create the same file in the same instance. In this case
FileExists returns for at least one of the processes that
file.lock has already been created.
LockFile is the same as FileExists except that it does
not check whether file already exists.
FileExists returns
1 |
if |
2 |
if |
3 |
if |
0 |
otherwise, |
Martin Schlather, schlather@math.uni-mannheim.de, http://ms.math.uni-mannheim.de
## Not run:
## the next command checks whether the file 'data.rda'
## or the file 'data.rda.lock' exists. If so, a positive
## value is returned. If not, the file 'data.rda.lock'
## is created and the value 0 returned.
FileExists("data.rda")
## the next command deletes the file 'data.rda.lock'
LockRemove("data.rda")
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.