Benoît Minisini schreef: >> Ron schreef: >>> How to watch new data that's added to a logfile? >>> >>> I want to make an apache log monitor, so I thought I could do that with >>> FILE READ WATCH, but thats not suited it seems, that one only seems keep >>> generating File_Read events continuous. >>> >>> In short: >>> I want to open a file readonly. >>> Then seek to end of file (or just before it) >>> Then only get file_read events when new lines/data are added (by >>> apache).. >>> >>> Anyone has any ideas? >> In response to my own question I have tested with this: >> >> It creates a file and reads it, event File_Read() keeps getting raised, >> even after end of file. >> >> ' Gambas module file >> PRIVATE hFile AS File >> PRIVATE hFile2 AS File >> >> PUBLIC SUB Main() >> >> ' create test file >> hFile = OPEN "/tmp/file" FOR WRITE CREATE >> PRINT #hFile, "0123456789"; >> CLOSE #hFile >> >> ' watch it >> hFile2 = OPEN "/tmp/file" FOR READ WATCH >> >> END >> >> PUBLIC SUB File_Read() >> >> DIM iByte AS Byte >> >> READ #hFile2, iByte >> PRINT " "; iByte; >> >> END >> >> It prints: >> 48 49 50 51 52 53 54 55 56 57 >> >> And then gives error "End of File" >> >> This is not what I expected, shouldn't it stop before end of file? >> >> Gambas 2.12, gb.qt >> >> Regards, >> Ron_2nd. >> > > It should, but alas this is not the way Linux works as explained in the man > page of the select() system call. > > A file descriptor is ready to read if the read() system call won't block. And > this is the case even if the end of file is reached, as then read() returns > an > error (and so does not block!). > > If you actually want to do what the "tail" command (watching a file and print > its contents), you should do that: > > - Get the file size every second. > > - If the file size has changed since the last time, read the file from its > last position until the end of the file. >
Had something build, but it was using a bit more cpu cycles than I wanted, ones every second is a nice compromise... will try, thanks. Regards, Ron_2nd. ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
