For my application i need to save all kind of console logs in the text or log file. I am using Log4Cocoa to generating different kind of logs. So how can i save all those console logs into the file? Could anyone please help me.
Thanks
With Log4Cocoa, each logger can have one or more destinations attached to it. So, if you attach a file appender to the root logger object, every log message will be sent to that file. When you initialize the logging system, add something like:
NSString *logFileName = #"path-to-your-log-file";
[[L4Logger rootLogger] addAppender:
[[L4FileAppender alloc] initWithLayout:[L4Layout simpleLayout]
fileName:logFileName];
If you use the L4FileAppender, the file you write to can grow without bounds. So, you might consider using either an L4RollingFileAppender or L4DailyRollingFileAppender instead. The L4RollingFileAppender rolls the file based on file size. The L4DailyRollingFileAppender rolls the file based on time. Despite what the name suggests, you can configure an L4DailRollingFileAppender to roll at different time periods (every minute, every hour, every 1/2 day, etc.).
If you do use a file appender, then you need to give some thought to how you are going to get the log files off of your device, particularly if you need to do logging in the production version of your application.
Much as I like the elegance of Log4Cocoa, I wound up switching to NSLogger (https://github.com/fpillet/NSLogger) and you might want to give it a look.
Related
I have a rails app and I would like to display the log in the app itself. This will allow administrators to see what changes were recently made without entering the console and using the file with the logs. All logs will be displayed in the application administration. How is it possible to implement and what kind of gems do I need to use?
You don't need a Gem.
Add a controller, read the logfiles and render the output in HTML.
Probably need to limit the number of lines you read. Also there might be different log files to chose from.
I don't think this is a good idea though. Log files are for finding errors and you should not need them in your day to day work, unless you manage ther server.
Also they might contain sensitive data (CC Numbers, Pwds, ...) and it might get complicated when you use multiple servers with local disks.
Probably better to look at dedicated tools for this and handle logs outside of your application.
Assuming that you have git associated with your application or git bash installed in your system.
For displaying log information for the development mode, migrate to your application folder in your console/terminal and type tail -f log/development.log
I am importing some legacy code into an iOS app that uses stdout for some diagnostic output. Of course, iOS does not like you to write to stdout at all, and I need to get that output anyway. I would like to redirect this output to a file, then use the same legacy code again, redirecting the output to a different file. Does anyone know of a way to do this?
I've tried the simplistic
freopen(p, "w", stderr);
This does work--but only once. After using this call, all output to stdout is forever redirected. That's OK, but subsequent calls to redirect the output to a new location cause system instability that eventually leads to a crash. (I have tested this running from XCode, but not directly from a rebooted iPad. I don't know for sure the instability persists if not running in XCode using DEBUG mode.)
I've also tried the method in this post. This works, too, but does not return the system to its original state, and again, only works once. (If you try this at home, include Apple's <unisys.h> instead of <io.h>, and leave the _ off of calls like _dup and _dup2.)
I really don't want to have to go through the code and replace all uses of printf, etc to use an explicit file. In addition to being time consuming, error prone, and ugly, the code is open source. I don't expect the original authors would appreciate my changes, and I don't really want to have to reintegrate the changes each time the original project is updated.
Thoughts?
I have code using the SysOperationFrameworkService, and after a model-deploy or some other set of circumstances, many users get Function SysOperationDataContractInfo::newParameterInfo has been incorrectly called..
It's unable to be resolved with full-compile, sync, full CIL, deleting XPPIL files, deleting AUC/KTI, usage data, security (they're admin), refreshing caches (server &client), etc. and I have a ticket open with Microsoft and they're struggling.
I've narrowed the issue down to when the service group AxClient located in the AOT at \Service Groups\AxClient WSDL files get deployed to C:\Users\[User]\AppData\Local. Either those files existing there, or something happening when those files get deployed is needed.
Any idea how/what causes these files (AxClient.wsdl, etc) to be created? With a user who happens to be "working", I can close the client, delete all the files, open the client, and no files will exist...then I perform a SysOp process and those files get created during that process. With the non-working user, with same security on the same machine does it, the files don't get created.
I have found that the
"Function SysOperationDataContractInfo::newParameterInfo has been incorrectly called" has been throwed because of a possible bug in the kernel when calling the "dictMethod = new DictMethod(UtilElementType::ClassInstanceMethod, dictClass.id(), methodName);" in the SysOperationServiceController.getServiceOperation() method. In my case the new DictMethod was sometimes unable to get the method parameter from a superclass, causing the _parentMethodParameterName check fail in the SysOperationDataContractInfo.newParameterInfo.
So, I solved the issue just by doing an override of the super method where the parameter could not be retrieved and then just calling super(_parameter), then everything went well.
Have you tried axclicfg.exe -> connections -> refresh
I want to write to/delete a file but sometimes I get a crash if the file is in use by another program. How do I check to see whether the file is opened by another process or I can open it for writing?
The problem is, that between the time you check to see if you could get exclusive access and opening the file, something else gets exclusive access to the file, and you get the exception anyway.
The only fool proof way to see if you can get an exclusive lock on a file is to try and get an exclusive lock on the file, if you get it you have it.
If not, you catch the exception, and either
Go do something else
Wait a while and try again
It's one of life’s situations where it's better to ask for forgiveness than permission :)
There is a new way to get the origin of file locking for Vista and up here:
http://www.remkoweijnen.nl/blog/2011/01/03/cannot-access-files-but-need-the-origin/
UserMode:
The best way to write to a locked file is to ask the user to close it in the other process. In batch processes you should ignore such a file and log the problem. Providing the name of the other process is a very good way to find a solution for the user.
Not sure in which programming language you'd like to check if you can write to a file. In Java, java.io.File.canWrite() can do the job for you.
General:
In UNIX-like OS, you can use the lsof command.
If you want to see which program holds a handle to your file, use the Process Monitor (download from MicroSoft).
This tool has a command line interface, so you could use your language's scripting interface (for example java.lang.Process) to run the tool and display a useful error message.
IsFileInUse as given in http://delphi.about.com/cs/adptips1999/a/bltip0999_3.htm
Is is possible to open a text file and read the contents while another application is updating the file, in such a way that it does not cause a lock conflict?
I need to monitor a log file from one application which is updated by another application each time an event occurs.
I do check if the file is in use before I try to read it, but that does not seem to work in all cases.
Thanks, Pieter
it depends on how the first app open that file.
i.e when calling CreateFile API to open a file, there is dwShareMode param which tells the api how to open it (if this was given 0, it can't be accessed from other applications IIRC).
otherwise there should be no problem with reading from that file.
if im not mistaken, to check if that file is being opened read only u can call
something like
CreateFile(pchar(fName), GENERIC_READ or GENERIC_WRITE, 0, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0) ;
Download Process Monitor from Sysinternals.
Open the filter dialog and add a "path" filter for your log file.
Start the log-writing application (I'll call this "logwriter").
Look for and click on the event where logwriter does a CreateFile.
Under "Detail", it should have "Desired Access: Generic Write". And it should have "ShareMode: Read", which corresponds to FILE_SHARE_READ in the call to CreateFile. What it means is, "I, logwriter, permit others to read my file".
Now run your log-reading application ("logreader"), and do the same exercise.
The Detail should have "Desired Access: Generic Read". And it should have "ShareMode: Read, Write", which means, "I, logreader, permit others, including logwriter, to read and write to the log file".
Those are the most sensible values, I think, and they will prevent locking. Other combinations may be permissible. There is a table here.
Now, you haven't said what happens when it "does not seem to work in all cases". What to do next will really depend on the details. Hopefully the above will give you enough information to work out what is going wrong.
You won't get a lock conflict because the writing application is very unlikely to have locked the file. Doing what you suggest generally works without problems (it's what the UNIX tail -f command does) and those minor glitches that do occur can be ignored. I've written a couple of log monitoring apps in te past that worked like this, with no problems.
Try using FileSystemWatcher to get events when a file is updated.
A more delphi friendly link
Quite apart from getting the file sharing to work right which may be impossible depending on what the other program requests, some programs will close the file between accesses.
I have had success in the past with my program waiting for the file to become available, then quickly opening it, grabbing the needed data and closing it. At least in DOS an attempt to access a locked file caused a few retries, and I bumped up this setting, so that if the other program tried for the file while I had it they would simply be delayed and never see an error.
I was even able to update the file (I made sure NOT to close it in between!) without the other program ever knowing a thing.
Ugly as sin but we couldn't change the other program so it was the only way to get the job done. It was deployed in-house for years, I never heard a peep from the users of that system. It finally went away when the machinery the other program controlled was retired.
XpoLog will do the trick without changing your env or code, XpoLog log monitor
Avar is right - you are at the mercy of the writing program here. If they are locking the file, then there are a couple of things you can do:
1 - Check for a change in the "last modified" date time - if that changes, then you know something has happened.
2 - If the mod datetime did change, then (depending on the size of the file) it might be good enough to create a copy of the file and check that.
we use "Tail for win32",
i know its not delphi but it might be useful
http://tailforwin32.sourceforge.net/