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Annotation of wpscripts/ztransfer/fileops.pm, Revision 1.1.1.1

1.1       yason       1: #!/usr/bin/perl
                      2: # $Id: fileops.pm,v 1.1.1.4 2006/02/17 09:16:23 init Exp $
                      3: package fileops;
                      4: use log;
                      5:
                      6: my $FILE_LOCK = "/var/run/ztransfer.lock";
                      7:
                      8:
                      9: sub cleanup()
                     10: {
                     11:     # clanup procedure
                     12:     # remove all .rar files in /tmp
                     13:     # THIS CODE SHOULD BE FIXED
                     14:     `rm -f /tmp/*.rar`;
                     15: }
                     16:
                     17:
                     18: sub checkdir($)
                     19: {
                     20:     my $file = shift;
                     21:     chomp( my $dir = `dirname '$file'` );
                     22:
                     23:     if(! -e $dir)
                     24:     {
                     25:        $_ = system("mkdir -p '$dir'");
                     26:            if($_ == 0)
                     27:            {
                     28:                log::main("Created directory $dir");
                     29:            }
                     30:            else
                     31:            {
                     32:                # directory has not created
                     33:                log::error("Can not create directory $dir");
                     34:            }
                     35:     }
                     36:
                     37: }
                     38:
                     39:
                     40: sub take_lock()
                     41: {
                     42:     open( FILE, ">$FILE_LOCK") or log::critical("Can not create lock file $FILE_LOCK");
                     43:     # write PID of current process to file
                     44:     print FILE $$;
                     45:     close(FILE);
                     46: }
                     47:
                     48:
                     49: sub release_lock()
                     50: {
                     51:     # I think this is bad for a while
                     52:     `rm $FILE_LOCK`;
                     53: }
                     54:
                     55:
                     56: sub check_lock()
                     57: {
                     58:     # I'm really sure that this technique (file-locks) is not very
                     59:     # good idea since it is no good way to determine if one copy
                     60:     # of this script is already running now.
                     61:     # My implementation based on writing a PID of a current process
                     62:     # and (on startup) check if that file (or PID in it) is exists in
                     63:     # processes tree (`ps ax`). It uses standart utility grep(1).
                     64:     my $PID;
                     65:
                     66:     if(! -e $FILE_LOCK)
                     67:     {
                     68:        # continue running main transfer code
                     69:        return()
                     70:     }
                     71:     else
                     72:     {
                     73:        open(FILE, $FILE_LOCK) or log::critical("Can not open existing lock file $FILE_LOCK");
                     74:        $PID = <FILE>;
                     75:        close(FILE);
                     76:        $_ = `ps ax | egrep '\\b$PID\\b'`;
                     77:         if($_ ne '')
                     78:         {
                     79:            # another copy is running
                     80:            log::critical("Another copy is running! Exiting..");
                     81:         }
                     82:         else
                     83:         {
                     84:            # previous run of script ends incorrectly
                     85:            # and he hadn't remove his lock
                     86:
                     87:            # return to main (should call take_lock() within it hardly)
                     88:            return()
                     89:         }
                     90:     }
                     91: }
                     92:
                     93: return(1);