I have a problem with my code. It doesn't print out an error, it works but it doesn't do what I actually need it to do. I won't be posting all of the code because it is not needed, I will just post the line we need.
So I have this line of code:
TIME1=$( { time awkfun ; } 2>&1 >/dev/null);
Where awkfun is a function that should print 500 integers, and TIME1 is a variable to store the time that the function will need to run and print. Problem is that normally as I said the function would print around 500 integers in this occasion though that I am using this, it just runs and does the calculations but is not printing. So it actually runs the awkfun function but doesn't let it print, in the time output for this function I also need the time it needs to print everything.
How to do that?
I hope I explained it as good as possible, if any questions arise please don't hesitate to comment, thanks in advance!
P.S
Running in ksh in oracle solaris.
Here is the correct sequence. Adjust as needed:
TIME1=`time (awkfun > /dev/tty) 2>&1`
Related
I wonder if there is a way to display the current time in the R command line, like in MS DOS, we can use
Prompt $T $P$G
to include the time clock in every prompt line.
Something like
options(prompt=paste(format(Sys.time(), "%H:%M:%S"),"> "))
will do it, but then it is fixed at the time it was set. I'm not sure how to make it update automatically.
Chase points the right way as options("prompt"=...) can be used for this. But his solutions adds a constant time expression which is not what we want.
The documentation for the function taskCallbackManager has the rest:
R> h <- taskCallbackManager()
R> h$add(function(expr, value, ok, visible) {
+ options("prompt"=format(Sys.time(), "%H:%M:%S> "));
+ return(TRUE) },
+ name = "simpleHandler")
[1] "simpleHandler"
07:25:42> a <- 2
07:25:48>
We register a callback that gets evaluated after each command completes. That does the trick. More fancy documentation is in this document from the R developer site.
None of the other methods, which are based on callbacks, will update the prompt unless a top-level command is executed. So, pressing return in the console will not create a change. Such is the nature of R's standard callback handling.
If you install the tcltk2 package, you can set up a task scheduler that changes the option() as follows:
library(tcltk2)
tclTaskSchedule(1000, {options(prompt=paste(Sys.time(),"> "))}, id = "ticktock", redo = TRUE)
Voila, something like the MS DOS prompt.
NB: Inspiration came from this answer.
Note 1: The wait time (1000 in this case) refers to the # of milliseconds, not seconds. You might adjust it downward when sub-second resolution is somehow useful.
Here is an alternative callback solution:
updatePrompt <- function(...) {options(prompt=paste(Sys.time(),"> ")); return(TRUE)}
addTaskCallback(updatePrompt)
This works the same as Dirk's method, but the syntax is a bit simpler to me.
You can change the default character that is displayed through the options() command. You may want to try something like this:
options(prompt = paste(Sys.time(), ">"))
Check out the help page for ?options for a full list of things you can set. It is a very useful thing to know about!
Assuming this is something you want to do for every R session, consider moving that to your .Rprofile. Several other good nuggets of programming happiness can be found hither on that topic.
I don't know of a native R function for doing this, but I know R has interfaces with other languages that do have system time commands. Maybe this is an option?
Thierry mentioned system.time() and there is also proc.time() depending on what you need it for, although neither of these give you the current time.
Me and my friend are working on a program that keeps track of swimmers times and all the times totaled is there aggregate. We also ask that the swimmers name which is equal to Name.
We are able to print out...
print('Swimmer had a total time of',aggregates[Name])
but the %Name stop the program from running properly, any suggestions to what we could use instead or maybe what we're doing wrong would be very helpful. Thanks!
print('''%s had a total aggregate time of
''',aggregates[Name] %Name)
Formatting print should be done like print("%s had a t..." % Name, aggregates[Name])
I have a question, I have been reviewing some code and in one script, the authors use:
if(0){
#do something
}
Any help in what if(0) means?
The author (most likely) put the block of code in an if statement so that they could easily remove it if necessary without having to comment it out (or remove it). Similar to if(true) or if(false), you just need to change one value and it would skip that code.
Upon reviewing the code, developers should remove these kinds of statements once they've finalized all their source code not to confuse others.
Looks like something that will never be executed, since 0 = FALSE. Most probably this is a manual switch to test some code in parenthesis.
Blasphemy I know to ask IF it is possible to do something in R, but here I am!
I am interested in the ability to create a function that will place code into the console. In other words, if the user types in f("3+3") and hits enter then the console will be waiting for the next command with > 3+3. Then when the user hits enter, it will return 6 in this case. Possible? Any ideas?
I wish I had more to share but I've never even thought this functionality would be useful before...
One way you could do this is to call system2() to invoke an external utility that synthesizes keyboard input. I've written a C++ program called sendkeys that can do this on Windows by (ultimately) calling SendInput(). Demo:
system2('sendkeys','3\\\\+3');
3+3
## [1] 6
(The backslash escaping is necessary because of the way my utility parses its input; + is a metachar that must be escaped to become literal.)
Let me know if you want my C++ code.
Would that be the kind of function you would need? Maybe it is not a very elegant solution, though.
printEval <- function(x){
cat(">", x,"\n")
cat ("Press [enter] to continue")
line <- readline()
eval(parse(text=x))
}
EDIT: Sorry, I just noticed that the eval(parse()) solution was already suggest by #Ping in the comment field right under the question.
I'm trying to write a lua script that reads input from other processes and analyzes it. For this purpose I'm using io.popen and it works as expected in Windows, but on Unix(Solaris) reading from io.popen blocks, so the script just waits there until something comes along instead of returning immediately...
As far as I know I can't change the functionality of io.popen from within the script, and if at all possible I would rather not have to change the C code, because then the script will then need to be bound with the patched binary.
Does that leave me with any command-line solutions?
Ok got no answers so far, but for posterity if someone needs a similar solution I did the following more or less
function my_popen(name,cmd)
local process = {}
process.__proc = assert(io.popen(cmd..">"..name..".tmp", 'r'))
process.__file = assert(io.open(name..".tmp", 'r'))
process.lines = function(self)
return self.__file:lines()
end
process.close = function(self)
self.__proc:close()
self.__file:close()
end
return process
end
proc = my_popen("somename","some command")
while true
--do stuf
for line in proc:lines() do
print(line)
end
--do stuf
end
Your problems seems to be related to buffering. For some reason the pipe is waiting for some data to be read before it allows the opened program to write more to it, and it seems to be less than a line. What you can do is use io.popen(cmd):read"*a" to read everything. This should avoid the buffering problem. Then you can split the returned string in lines with for line in string.gmatch("[^\n]+") do someting_with(line) end.
Your solution consist in dumping the output of the process to a file, and reading that file. You can replace your use or io.popen with io.execute, and discard the return value (just check it's 0).