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best wishes to all.

    1: #!/usr/bin/perl
    2: 
    3: # loncaparestoreconfigurations - restore data to new LON-CAPA conf files
    4: #
    5: # $Id: loncaparestoreconfigurations,v 1.16 2003/02/03 18:03:52 harris41 Exp $
    6: #
    7: ###
    8: 
    9: # This tool helps in updating a system.  It restores information for
   10: # configuration files (.lpmlnew or other backup notations).
   11: 
   12: # By default, the .lpmlsave suffix is used.
   13: # Alternatively, there can be two other invocations
   14: # Invocation #1:
   15: #   ARGV[0]=suffix
   16: #   ARGV[1]=.bak
   17: # Invocation #2:
   18: #   ARGV[0]=lasttimestamp
   19: 
   20: # The criteria for the lasttimestamp is that the 
   21: # file suffix is a '.' followed by a 14-digit
   22: # time-stamp (YYYYMMDDhhmmss).
   23: # The time-stamp with the greatest value is
   24: # taken as the backup file.
   25: 
   26: # --------------------------------------------- Define program version variable
   27: $VERSION = sprintf("%d.%02d", q$Revision: 1.16 $ =~ /(\d+)\.(\d+)/);
   28: 
   29: # ---------------------------------------------- Process command-line arguments
   30: my $suffix='.lpmlsave';
   31: my $suffixpragma='';
   32: if ($ARGV[0] eq 'suffix') {
   33:     $suffix=$ARGV[1] if $ARGV[1]=~/^[\.\w]+$/;
   34: }
   35: elsif ($ARGV[0] eq 'lasttimestamp') {
   36:     $suffixpragma='lasttimestamp';
   37: }
   38: 
   39: use strict; # restrict unsafe and poorly coded constructs
   40: 
   41: # ------------------------------------ Configuration files to be concerned with
   42: my @special_conf_files=(
   43: 			'/etc/httpd/conf/loncapa.conf',
   44: 			);
   45: 
   46: my %pvar; # store the PerlSetVar variable key/value combinations
   47: 
   48: # --------------------------------------------- Process the configuration files
   49: # NOTE that I have structured this processing to make NO assumptions
   50: # about the processing of each configuration file.  So, in terms
   51: # of keeping each file's processing algorithms self-contained, I am not
   52: # modularizing things (where it is obvious that they might be modularized.)
   53: CONFLOOP: foreach (@special_conf_files) {
   54: 
   55:     my $lpmlold; # holds information that needs to be read
   56:     my $lpmlnew; # holds information that needs to be modified
   57: 
   58:     my $lpmlnew_file; # file location of information that needs to be modified
   59: 
   60: # ---------------------------------------------------------------- loncapa.conf
   61:     if (/^\/etc\/httpd\/conf\/loncapa.conf$/ and
   62: 	-e '/etc/httpd/conf/loncapa.conf')
   63:       {
   64: 	if ($suffixpragma eq 'lasttimestamp' and
   65: 	    -e '/etc/httpd/conf/loncapa.conf')
   66: 	  {
   67: 	    $suffix=&getsuffix('/etc/httpd/conf/loncapa.conf');
   68: 	    unless (-e '/etc/httpd/conf/loncapa.conf'.$suffix)
   69: 	      {
   70: 		next CONFLOOP;
   71: 	      }
   72: 	    $lpmlold="\n".&readfile('/etc/httpd/conf/loncapa.conf'.$suffix);
   73: 	    $lpmlnew_file='/etc/httpd/conf/loncapa.conf';
   74: 	    $lpmlnew=&readfile($lpmlnew_file);
   75: 	  }
   76: 	else
   77: 	  {
   78: 	    $lpmlold="\n".&readfile('/etc/httpd/conf/loncapa.conf');
   79: 	    $lpmlnew_file='/etc/httpd/conf/loncapa.conf'.$suffix;
   80: 	    unless (-e $lpmlnew_file)
   81: 	      {
   82: 		next CONFLOOP;
   83: 	      }
   84: 	    $lpmlnew=&readfile($lpmlnew_file);
   85: 	  }
   86: 	while($lpmlold=~/\n\s*PerlSetVar\s+(\S+)\s+(\S+)/mcg)
   87: 	  {
   88: 	    my $pkey=$1; my $pval=$2;
   89: 	    $pvar{$pkey}=$pval;
   90: 	  }
   91: 	foreach my $pkey (keys %pvar)
   92: 	  {
   93: 	    my $pval=$pvar{$pkey};
   94: 	    $lpmlnew=~s/(\n\s*PerlSetVar\s+$pkey\s+)\S+/$1$pval/;
   95: 	  }
   96: 	open(OUT,'>'.$lpmlnew_file) or
   97: 	    die('Cannot open '.$lpmlnew_file.' for output'."\n");
   98: 	print(OUT $lpmlnew);
   99: 	close(OUT);
  100:       }
  101: 
  102: # ---------------------- smb.conf (probably will be deprecated in 2004 or 2005)
  103:     elsif (/^\/etc\/smb.conf$/ and -e "/etc/smb.conf$suffix")
  104:       {
  105: 	if ($suffixpragma eq 'lasttimestamp')
  106: 	  {
  107: 	    $suffix=&getsuffix('/etc/smb.conf');
  108: 	    unless (-e '/etc/httpd/conf/loncapa.conf'.$suffix)
  109: 	      {
  110: 		next CONFLOOP;
  111: 	      }
  112: 	    $lpmlnew = &readfile('/etc/smb.conf');
  113: 	    $lpmlnew_file = '/etc/smb.conf';
  114: 	  }
  115: 	else
  116: 	  {
  117: 	    $lpmlnew = &readfile('/etc/smb.conf'.$suffix);
  118: 	    $lpmlnew_file = '/etc/smb.conf'.$suffix;
  119: 	  }
  120: 	$lpmlnew =~ s/\{\{\{\{\[(.*?)\]\}\}\}\}/$pvar{$1}/ge;
  121: 	open(OUT,'>'.$lpmlnew_file) or
  122: 	    die('Cannot open '.$lpmlnew_file.' for output'."\n");
  123: 	print(OUT $lpmlnew);
  124: 	close(OUT);
  125:       }
  126:     elsif (/^\/etc\/samba\/smb.conf$/ and -e "/etc/samba/smb.conf$suffix")
  127:       {
  128: 	if ($suffixpragma eq 'lasttimestamp')
  129: 	  {
  130: 	    $suffix = &getsuffix('/etc/samba/smb.conf');
  131: 	    unless (-e '/etc/samba/smb.conf'.$suffix)
  132: 	      {
  133: 		next CONFLOOP;
  134: 	      }
  135: 	    $lpmlnew = &readfile('/etc/samba/smb.conf');
  136: 	    $lpmlnew_file = '/etc/samba/smb.conf';
  137: 	  }
  138: 	else
  139: 	  {
  140: 	    $lpmlnew = &readfile('/etc/samba/smb.conf'.$suffix);
  141: 	    $lpmlnew_file = '/etc/samba/smb.conf'.$suffix;
  142: 	  }
  143: 	$lpmlnew =~ s/\{\{\{\{\[(.*?)\]\}\}\}\}/$pvar{$1}/ge;
  144: 	open(OUT,'>'.$lpmlnew_file) or
  145: 	    die('Cannot open '.$lpmlnew_file.' for output'."\n");
  146: 	print(OUT $lpmlnew);
  147: 	close(OUT);
  148:       }
  149:   }
  150: 
  151: # --------------------------------- getsuffix: get the latest time stamp suffix
  152: # === INPUT:  filename without suffix
  153: # === OUTPUT: the latest time stamp suffix; 14 digits YYYYMMDDhhmmss
  154: # === ERROR:  cannot read the directory in which the filenames reside
  155: sub getsuffix ($)
  156:   {
  157:     my ($file) = @_;
  158:     print("$file\n");
  159:     my $dir = $file; $dir =~ s/([^\/]+)$//;
  160:     my $filename = $1;
  161:     opendir(DIR,$dir) or
  162: 	die('Cannot open directory '.$dir.' for viewing'."\n");
  163:     my @a = grep {/$filename\.\d{14}/} readdir(DIR);
  164:     closedir(DIR);
  165:     map {s/$filename\.//;} @a;
  166:     my @b = sort {$a<=>$b} @a;
  167:     my $suffix = '.'.$b[$#b];
  168:     return($suffix);
  169:   }
  170: 
  171: # -------------------------- readfile: get the file contents in a scalar string
  172: # === INPUT:  filename
  173: # === OUTPUT: the filename's contents
  174: # === ERROR:  cannot read the file
  175: # === NOTE:   big files will hog computer memory
  176: sub readfile ($)
  177:   {
  178:     my ($filename) = @_;
  179:     my $contents = '';
  180:     open(IN,'<'.$filename) or die ('Cannot read '.$filename."\n");
  181:     while(<IN>) {$contents .= $_;}
  182:     close(IN);
  183:     return($contents);
  184:   }
  185: 
  186: =pod
  187: 
  188: =head1 NAME
  189: 
  190: B<loncaparestoreconfigurations> - restore data to new LON-CAPA conf files
  191: 
  192: =head1 SYNOPSIS
  193: 
  194:  perl loncaparestoreconfigurations suffix .lpmlnew
  195: 
  196: =head1 DESCRIPTION
  197: 
  198: During software upgrades, it is possible that configuration files will change.
  199: It is important to "intelligently" preserve the machine-specific configuration
  200: data.  This script is meant to run B<after> the software upgrade.
  201: 
  202: For example, consider the configuration file F<loncapa.conf>.
  203: During the software upgrade (not performed by by F<loncapa.conf>),
  204: the following happens:
  205: 
  206:  loncapa.conf is NOT overwritten
  207: 
  208: rather,
  209: 
  210:  a NEW file B<loncapa.conf.lpmlnew> is GENERATED
  211:  (cp UPGRADEDIR/loncapa.conf SYSTEMDIR/loncapa.conf.lpmlnew)
  212: 
  213: This script can be described as:
  214: 
  215: =over 4
  216: 
  217: =item *
  218: 
  219: modifying SYSTEMDIR/loncapa.conf.lpmlnew, and
  220: 
  221: =item *
  222: 
  223: the modification consists of reading values from the old loncapa.conf and
  224: placing them in loncapa.conf.lpmlnew.
  225: 
  226: =back
  227: 
  228: Regarding F<loncapa.conf>, for backwards compatibility, this script tries
  229: to read values out of F<access.conf>.
  230: 
  231: This script also currently works with F<smb.conf> (a standard Linux
  232: configuration file associated with sharing the Linux filesystem with
  233: Windows machines).
  234: 
  235: =head2 Working with the file suffix
  236: 
  237: The script is designed to work according to two strategies.
  238: 
  239: =over 4
  240: 
  241: =item * B<aggressive update>
  242: 
  243: In the aggressive update strategy, two things should happen:
  244: 
  245: =over 4
  246: 
  247: =item * The configuration file should be replaced
  248: 
  249: Therefore, the system administrator "trusts" the software update process
  250: and this script to handle everything correctly.
  251: 
  252: =item * Information should never be lost
  253: 
  254: Therefore, a backup copy should be made that is unique to the time
  255: the action is taken and is never overwritten or destroyed by the
  256: automated process.
  257: 
  258: =back
  259: 
  260: =item * B<passive assistance>
  261: 
  262: =over 4
  263: 
  264: =item * The configuration file should not be replaced
  265: 
  266: The system administrator does not trust the software update process.
  267: She would rather have a new file "intelligently" generated, and, only
  268: by her direct approval, have the new file substitute the contents
  269: of the current configuration file.
  270: 
  271: =item * The script should try to help the system administrator
  272: 
  273: Therefore, a new copy is made with the suffix ".lpmlnew".  This
  274: new copy is modified with data from the existing configuration file.
  275: The system administrator is prompted (by the rest of the software
  276: upgrade process) to resolve the new changes to the configuration
  277: file.
  278: 
  279: =back
  280: 
  281: =back
  282: 
  283: Correspondingly,
  284: 
  285:  perl loncaparestoreconfigurations suffix .lpmlnew
  286: 
  287: invokes this script in B<passive assistance> mode; whereas
  288: 
  289:  perl loncaparestoreconfigurations lasttimestamp
  290: 
  291: invokes this script in B<aggressive update> mode.
  292: 
  293: =head1 AUTHORS
  294: 
  295: 
  296: This script is free software; you can redistribute it
  297: and/or modify it under the same terms as LON-CAPA itself.
  298: 
  299: =cut