On 9/17/2008 9:03 AM, Dennis Fisher wrote:
Colleagues,
I am using R 2.7.2 on all three platforms (OS X; Windows; Linux) and I
have encountered the following problem:
I use R to issue a system call the execute a command in the OS. For
example:
system("DOSOMETHING TOSOMEFILE")
In most situations, this task completes successfully and control
returns to R. However, in rare situations, the target file
(TOSOMEFILE) is missing an EOL character in its final line. In that
situation, the task DOSOMETHING hangs and control never returns to R.
Exiting R requires that I kill the process.
I believe that a solution would be to add an EOL character to the
final line of the target file before executing DOSOMETHING. I presume
that this could be done by reading TOSOMEFILE with readLines,
appending an EOL character, writing to disk, then executing TOSOMEFILE
on the revised target.
No need to append the EOL, writeLines will automatically terminate each
line. readLines will by default give a warning if there wasn't one present.
Questions:
1. Is there are easier approach to the entire problem?
2. Is there any risk in having two EOL characters at the end of the
file (i.e., need I test for the presence of EOL at the end of the file
or can I append EOL to any file with no potential harm?
That really depends on what DOSOMETHING does. Does it care if there's
an extra blank line at the end? Can you tell it to ignore the lack of one?
Duncan Murdoch
Dennis
Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
