I was coding in GoLang, just working on personal interests, and one of my common practices is to package any commands necessary to running a program into a "runner.bat" file. This, of course, speeds up my workflow by not forcing me to type the same command(s) a thousand times. However, I noticed that when I ran my go program (a fairly simple Naive-Bayes algorithm for data processing), it would stall out. I hit ctrl + c and it threw "exit status 2". Based purely on experimentation, I discovered that if the directory had a file called "runner.bat" the go program would stall out, with no regards towards the contents of that file. If I removed my file or renamed it, everything runs just fine. My question being, why does this happen?
Related
I have a problem which I think might be solvable with a batch file, but I've only used batch files once or twice and don't know enough to try and solve this on my own. For context I'm running Windows 10 Home Edition, and have some programming experience, though it is primarily mathematical, i.e. R and MATLAB.
The problem is this: I have two programs, in this case Spotify and Toastify, which run together, with Toastify running in the background. I'll refer to them as S and T, respectively. If I run T, S runs as well, but if I close S, T remains running in the background. For reasons of convenience, I would rather that closing S also close T, so that when I want to use them again later I need only reopen T rather than checking if it's still running in the background, because T doesn't let you run multiple instances.
I'm wondering if there is an easy way to write a batch file (or something else if this isn't a good approach) that will open T (and so also S), and then 'listen' for S to close, at which point it closes T as well.
You need to use a Job Object. See Working example of CreateJobObject/SetInformationJobObject pinvoke in .net? and Kill child process when parent process is killed
Do not try 'monitoring for one process', that leaves zombies when the monitoring crashes.
I'm running into some considerable speed bottlenecks with a Python-Matplotlib-Xcode combination. I know some immediate responses will probably ask "Why are you doing python stuff in Xcode, just man up and use vim" --> I like the organizing ability and the built in version control, it makes elements of my work easier to deal with.
Getting python to run in xcode in the first place was a bit more tricky than I had hoped, but its possible. Now I have the following scenario:
A master file, 'main.py' does all the import stuff for me and sets up some universal formatting to make all the figures (for eventual inclusion in my PhD thesis) nice and uniform. Afterwards it runs a series of execfile commands to generate whichever graphics I need. Two things I can think of right off the bat:
1) at the very beginning of main.py after I import all the normal python stuff you tend to need, I call a system script which checks whether a certain filesystem is mounted. I keep all my climate model data on there since my local hard drive is too small to deal with all of it at once. Python pauses itself and waits for the system to do its thing, but once the filesystem has been found, it keeps going. Usually this only needs to happen once in the morning when I get to work, or if the VPN server kicked me off for whatever reason. (Side question, it'd be cool to know if theres a trick to automate an VPN login to reconnect as soon as it notices its not connected)
2) I'm not sure how much xcode is using on its own. running the same program from terminal is (somewhat) faster. I've tried to be memory conscience and turn off stuff I don't need while running the python/xcode combination.
Also, python launches a little window whenever I call plt.show(), this in itself takes time, I've considered just saving them as quick png files and opening them with some other viewer, although I guess that would also have to somehow take time to open up. Given how often these graphics change as I add model runs or think of nicer ways of displaying the data, it'd be nice to not waste something on the order of 15 to 30 minutes (possibly more) out of the entire day twiddling my thumbs and waiting for a window to pop up.
Benchmark it!
import datetime
start = datetime.datetime.now()
# your plotting code
td = datetime.datetime.now() - start
print td.total_seconds() # requires python version >= 2.7
Run it in xcode and from the command line, see what the difference is.
Want to upgrade my file management productivity by replacing 2 panel file manager with command line (bash or cygwin). Can commandline give same speed? Please advise a guru way of how to do e.g. copy of some file in directory A to the directory B. Is it heavy use of pushd/popd? Or creation of links to most often used directories? What are the best practices and a day-to-day routine to manage files of a command line master?
Can commandline give same speed?
My experience is that commandline copying is significantly faster (especially in the Windows environment). Of course the basic laws of physics still apply, a file that is 1000 times bigger than a file that copies in 1 second will still take 1000 seconds to copy.
..(howto) copy of some file in directory A to the directory B.
Because I often have 5-10 projects that use similar directory structures, I set up variables for each subdir using a naming convention :
project=NewMatch
NM_scripts=${project}/scripts
NM_data=${project}/data
NM_logs=${project}/logs
NM_cfg=${project}/cfg
proj2=AlternateMatch
altM_scripts=${proj2}/scripts
altM_data=${proj2}/data
altM_logs=${proj2}/logs
altM_cfg=${proj2}/cfg
You can make this sort of thing as spartan or baroque as needed to match your theory of living/programming.
Then you can easily copy the cfg from 1 project to another
cp -p $NM_cfg/*.cfg ${altM_cfg}
Is it heavy use of pushd/popd?
Some people seem to really like that. You can try it and see what you thing.
Or creation of links to most often used directories?
Links to dirs are, in my experience used more for software development where a source code is expecting a certain set of dir names, and your installation has different names. Then making links to supply the dir paths expected is helpful. For production data, is just one more thing that can get messed up, or blow up. That's not always true, maybe you'll have a really good reason to have links, but I wouldn't start out that way, just because it is possible to do.
What are the best practices and a day-to-day routine to manage files of a command line master?
( Per above, use standardized directory structure for all projects.
Have scripts save any small files to a directory your dept keeps in the /tmp dir, .
i.e /tmp/MyDeptsTmpFile (named to fit your local conventions) )
It depends. If you're talking about data and logfiles, dated fileNames can save you a lot of time. I recommend dateFmts like YYYYMMDD(_HHMMSS) if you need the extra resolution.
Dated logfiles are very handy, when a current process seems like it is taking a long time, you can look at the log file from a week ago and quantify exactly how long this process took, a week, month, 6 months (up to how much space you can afford). LogFiles should also capture all STDERR messages, so you never have to re-run a bombed program just to see what the error message was.
This is Linux/Unix you're using, right? Read the man page for the cp cmd installed on your machine. I recommend using an alias like alias CP='/bin/cp -pi' so you always copy a file with the same permissions and with the original files' time stamp. Then it is easy to use /bin/ls -ltr to see a sorted list of files with the most recent files showing up at the bottom of the list. (No need to scroll back to the top, when you sort by time,reverse). Also the '-i' option will warn you that you are going to overwrite a file, and this has saved me more than a couple of times.
I hope this helps.
P.S. as you appear to be a new user, if you get an answer that helps you please remember to mark it as accepted, and/or give it a + (or -) as a useful answer.
I've inherited a medium sized project in which the main (batch) program is fed work through a large set of shell scripts that do a lot of process control (waiting for process to complete, sleeping, checking for conditions, etc) [ and reprocessed through perl scripts ]
Are there other examples of process control by shell scripts ? I would like to see what other people have done as a comparison. (as i'm not really fond of the 6,668 line shell script)
It may lead to that the current program works and doesn't need to be messed with or for maintenance reasons - it's too cumbersome and doing it another way will be easier to maintain, but I need other examples.
To reduce the "generality" of the question here's an example of what I'm looking for: procsup
Inquisitor project relies on process control from shell scripts extensively. You might want to see it's directory with main function set or directory with tests (i.e. slave processes) that it runs.
This is quite general question, and therefore giving specific answers may be a little bit difficult. (And you wont be happy with 5000 lines long example.) Most probably architecture of your application is faulty, and requires rather complete rework.
As you probably already know, process control with bash is pretty simple:
./test_script.sh &
test_script_pid=$!
wait $test_script_pid # waits until it's done
./test_script2.sh
echo $? # Prints return code of previous command
You can do same things with for example Python subprocess (or with Perl, obviously). If you have complex architecture with large number of different programs, then process is obviously non-trivial.
That is an awfully bug shell script. Have you considered refactoring it?
From the sound of it, there may be a lot of instances where you could replace several lines of code with a call to a shell function. If you can simplify the code in this way, then it will be easier to see where there are errors in the logic.
I've used this tactic successfully with a humongous PERL script and it turned out to have some serious logic errors and to be a security risk because it had embedded passwords that were obfuscated in an easily reversible way. The passwords that were exposed could have been used by persons unknown (well, a disgruntled employee) to shut down an entire global network.
Some managers were leaning towards making a security exception because this script was so important, but when the logic error was explained and it was clear that this script was providing incorrect data, it was decided that no data was better than dirty data. The guy who wrote that script taught himself programming with a PERL book and the writing of the script.
I have a Perl script that runs via a system() command from C. On a specific site (SunOS 5.10), when that script is run, it nearly always takes 6 seconds or more. On other sites, it runs pretty much instantly (0.1s). If I run the script manually, i.e. not from the C code, it also runs instantly. I eventually tracked the slowness down (by spitting out the time a whole bunch in a lot of different places), to a single require line. The file that it is requiring is another Perl script we wrote. The script consists of a single require (this file here), 3 scalars that are assigned integer values, and a handful of time/date conversion routines. The file ends with a 1;. That single require appears to take as much as 6 seconds on occasion, but as I said, not always even on the same machine. I'm absolutely stumped here. My only last thought is to turn on profiling, but the site doesn't have Devel::Profiler and my only other option (that I know of) would be to add it to the Perl command which would require me altering and recompiling the C code (doable but non-trivial).
Anybody have ANY idea what could be going on here? I don't think I can/want to put the entire date.pl that is being required, but it's pretty much exactly as I described; I could answer any questions about it that you have.
Thanks in advance.
You might be interested in A Timely Start by Jean-Louis Leroy. He had a similar problem and tracked it down to a long and deep module search path where perl usually found the modules in the last entries in #INC.
Six seconds is a long time. Have you checked what your network is doing during this?
My first thought was that spawning the new process when using the system() command could be the problem, but six seconds is too long.
I don't know much about perl, but I could imagine that for any reason, the access of the time module could invoke a call to a network time server. Just to get synchronized. Maybe this takes so long or maybe it is getting a time out.
It could be that this only happens for a newly spawned process -- hence only when you use the system() command.
just wild guessing...
So, this does nothing to answer your question directly, but please tell me that you're not actually running on perl 4? Assuming you're on perl 5, you could remove the entire file and replace the require with use POSIX qw(ctime) to get the version that comes with Perl.
If you do have to support perl4, I'll merely grumble something about version 5 being fifteen years old now and go away. :)