File Buffering
I wrote and use a module that provides a standardized logging mechanism to STDOUT and to a defined log file. I have several Perl programs that run all of the time and use this module. The log file is opened at the program start and closed at the program end. There is nothing particularly fancy or complicated with the way that the module opens, writes, or closes the file. The file is created as a normal text file and regular print functions are used to write to it. While a given program is running an writing to the log file, the log file can be opened in Notepad and the contents examined. Herein lies the issue, the program seems to lag behind in the writes to the log file based upon the known program activity, i.e. there are entries I expect to see in the log file that are not there, but after a period of time, the log file will catch up and I will see the results. All entries to the log file are timestamped so that I know when events occurred. I thing that there is some kind of file buffering going on here, i.e. the log entries are in a file buffer that has not been flushed to the file. The file is using a specific file handle, i.e. it is not being written to STDOUT or STDERR. I have never really understood the buffering mechanism as employed by Perl and could use some knowledge in this area. Specifically, how can I force every write to the log file to be unbuffered? Is the problem with buffering or is there something else I should look at? Note: Using Perl 5.6.1 on Win2K. Dirk Bremer - Systems Programmer II - ESS/AMS - NISC St. Peters USA Central Time Zone 636-922-9158 ext. 8652 fax 636-447-4471 [EMAIL PROTECTED] www.nisc.cc ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: File Buffering
select YOURFILEHANDLE; $| = 1; # enjoy unbuffered file goodness -Original Message- From: Dirk Bremer (NISC) [mailto:[EMAIL PROTECTED] Sent: Friday, October 01, 2004 1:28 PM To: [EMAIL PROTECTED] Subject: File Buffering I wrote and use a module that provides a standardized logging mechanism to STDOUT and to a defined log file. I have several Perl programs that run all of the time and use this module. The log file is opened at the program start and closed at the program end. There is nothing particularly fancy or complicated with the way that the module opens, writes, or closes the file. The file is created as a normal text file and regular print functions are used to write to it. While a given program is running an writing to the log file, the log file can be opened in Notepad and the contents examined. Herein lies the issue, the program seems to lag behind in the writes to the log file based upon the known program activity, i.e. there are entries I expect to see in the log file that are not there, but after a period of time, the log file will catch up and I will see the results. All entries to the log file are timestamped so that I know when events occurred. I thing that there is some kind of file buffering going on here, i.e. the log entries are in a file buffer that has not been flushed to the file. The file is using a specific file handle, i.e. it is not being written to STDOUT or STDERR. I have never really understood the buffering mechanism as employed by Perl and could use some knowledge in this area. Specifically, how can I force every write to the log file to be unbuffered? Is the problem with buffering or is there something else I should look at? Note: Using Perl 5.6.1 on Win2K. Dirk Bremer - Systems Programmer II - ESS/AMS - NISC St. Peters USA Central Time Zone 636-922-9158 ext. 8652 fax 636-447-4471 [EMAIL PROTECTED] www.nisc.cc ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
Re: File Buffering
Peter and Michael, Your advice seems to have done the trick. Have a great weekend. Dirk Bremer - Systems Programmer II - ESS/AMS - NISC St. Peters USA Central Time Zone 636-922-9158 ext. 8652 fax 636-447-4471 [EMAIL PROTECTED] www.nisc.cc - Original Message - From: Peter Guzis [EMAIL PROTECTED] To: Dirk Bremer (NISC) [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Friday, October 01, 2004 15:44 Subject: RE: File Buffering select YOURFILEHANDLE; $| = 1; # enjoy unbuffered file goodness -Original Message- From: Dirk Bremer (NISC) [mailto:[EMAIL PROTECTED] Sent: Friday, October 01, 2004 1:28 PM To: [EMAIL PROTECTED] Subject: File Buffering I wrote and use a module that provides a standardized logging mechanism to STDOUT and to a defined log file. I have several Perl programs that run all of the time and use this module. The log file is opened at the program start and closed at the program end. There is nothing particularly fancy or complicated with the way that the module opens, writes, or closes the file. The file is created as a normal text file and regular print functions are used to write to it. While a given program is running an writing to the log file, the log file can be opened in Notepad and the contents examined. Herein lies the issue, the program seems to lag behind in the writes to the log file based upon the known program activity, i.e. there are entries I expect to see in the log file that are not there, but after a period of time, the log file will catch up and I will see the results. All entries to the log file are timestamped so that I know when events occurred. I thing that there is some kind of file buffering going on here, i.e. the log entries are in a file buffer that has not been flushed to the file. The file is using a specific file handle, i.e. it is not being written to STDOUT or STDERR. I have never really understood the buffering mechanism as employed by Perl and could use some knowledge in this area. Specifically, how can I force every write to the log file to be unbuffered? Is the problem with buffering or is there something else I should look at? Note: Using Perl 5.6.1 on Win2K. Dirk Bremer - Systems Programmer II - ESS/AMS - NISC St. Peters USA Central Time Zone 636-922-9158 ext. 8652 fax 636-447-4471 [EMAIL PROTECTED] www.nisc.cc ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
