Prva inačica za bullseye

[carnet-tools-cn.git] / cp-update

diff --git a/cp-update b/cp-update
index f4d66be..5514ee6 100755 (executable)
--- a/cp-update
+++ b/cp-update
@@ -35,7 +35,7 @@ sub DEBUG () { 0 };
 #
 my ($ProgramName, $UsageLong, $UsageShort, $VERSION);
 
-$VERSION = '2.0';
+$VERSION = '2.1';
 
 # Looks nicer without the slashes and dots
 ($ProgramName = $0) =~ s!.*/!!; # strip dir
@@ -109,7 +109,7 @@ $UsageShort .= " or type  $ProgramName --help  to be choked with help.\n";
 my ($MarkBegin, $MarkEnd, $Trailer, $ParamBegin, $ParamEnd, $Placement,
     $Package, $File, $Block, $Multi, $InsertRemove, $Comment, $CommentEnd,
     $MatchLine, $RegexpMatch, $StdinContent, $NewContent, $InPlace,
-    $NoClose, $FileHandle, @Lines);
+    $NoClose, $FileHandle, @Lines, $LinesCount);
 
 # Placement modes
 use constant APPEND_AT_END => 0;
@@ -251,7 +251,7 @@ do_it() and exit(0);
 # --------------
 
 sub do_it {
-  slurp();
+  $LinesCount = slurp();
   if (DO_CHANGE == $InsertRemove) {
     $StdinContent = &stdin_content;
     change() or add();
@@ -278,10 +278,11 @@ sub slurp() {
 
   # If FILE does not have a trailing newline, be sure to add it
   # before appending anything else.
-
   if (@Lines and $Lines[$#Lines] !~ m/\n$/s) {
     $Lines[$#Lines] .= "\n";
   }
+  
+  return scalar @Lines;
 }
 
 sub add() {
@@ -321,7 +322,9 @@ sub add() {
       push(@Lines, $StdinContent);
     }
   }
-  return scalar(@Lines); # whatever
+  # add the number of lines in added content to safety counter
+  $LinesCount += ($StdinContent =~ tr/\n//);
+  return $LinesCount; # whatever true
 }
 
 sub del() {
@@ -337,9 +340,12 @@ sub del() {
 
   my (@filtered);
   foreach (@Lines) {
-    push (@filtered, $_)
-      unless (/^$mybegin(?:$mytrailer)?$/o .. /^$myend(?:$mytrailer)?$/o);
-      
+    if (/^$mybegin(?:$mytrailer)?$/o .. /^$myend(?:$mytrailer)?$/o) {
+      # additional safety counter for double-check
+      -- $LinesCount;
+    } else {
+      push (@filtered, $_);
+    }
     # for safety check:
     $bm_found = 1 if (/^$mybegin(?:$mytrailer)?$/o);
     $em_found = 1 if (/^$myend(?:$mytrailer)?$/o);
@@ -352,7 +358,7 @@ sub del() {
     # safety exit    
     die "$ProgramName: no end-mark after begin-mark!\n";
   }
-  return scalar(@Lines); # whatever
+  return $LinesCount; # whatever
 }
 
 sub change() {
@@ -371,6 +377,7 @@ sub change() {
   $skip = 0; # skip original block
   foreach (@Lines) {
     if (! $done and $skip > 0) {
+      -- $LinesCount;
       if (/^$myend(?:$mytrailer)?$/o) {
         ++ $done; # skipped all that was to skip
       } else {
@@ -379,6 +386,7 @@ sub change() {
     }
     elsif (0 == $skip and $_ =~ /^$mybegin(?:$mytrailer)?$/o) {
       push (@filtered, $StdinContent);
+      $LinesCount += ($StdinContent =~ tr/\n//);
       $skip = 1;
     }
     else {
@@ -407,7 +415,7 @@ sub actualize() {
   # put it all thogether
   my $newContent = join('', @Lines);
 
-  unless (length($newContent)) {
+  unless (length($newContent) or 0 == $LinesCount) {
     # safety exit in last second :)
     die "$ProgramName: New content empty -- aborting file alteration!\n";
   }
@@ -430,10 +438,13 @@ sub actualize() {
       sysseek(*$FileHandle, 0, SEEK_SET)
        or die "$ProgramName: Failed to seek to the begining of file ($!)\n";
     }
-    my $wb = syswrite($FileHandle, $newContent);
-    if (! $wb or length($newContent) != $wb) {
-      # FIXME: try restoring backup copy
-      die "$ProgramName: Failed to write the content to '$File' ($!)\n";
+    if (length($newContent)) {
+      my $wb = syswrite($FileHandle, $newContent);
+      if (! $wb or length($newContent) != $wb) {
+        # FIXME: try restoring backup copy
+        my $ncl = length($newContent);
+        die "$ProgramName: Failed to write the content to '$File' (wb=$wb, len=$ncl, err:$!)\n";
+      }
     }
     if ($NoClose) {
       # this could be handy for files that had stuff appended
@@ -448,12 +459,15 @@ sub actualize() {
     $file_new .= '.cp-update.new'; # our .new file
     $file_old .= '.cp-update.old'; # our .old file
     # write content in new file in single write op
-    sysopen ($FileHandle, $file_new, O_CREAT|O_TRUNC|O_WRONLY)
+    sysopen ($FileHandle, $file_new, O_CREAT|O_TRUNC|O_WRONLY, (stat($File))[2])
       or die "$ProgramName: Failed to open file '$File' for writing ($!)\n";
-    my $wb = syswrite($FileHandle, $newContent);
-    if (! $wb or length($newContent) != $wb) {
-      unlink($file_new);
-      die "$ProgramName: Failed to write the content to '$File' ($!)\n";
+    if (length($newContent)) {
+      my $wb = syswrite($FileHandle, $newContent);
+      if (! $wb or length($newContent) != $wb) {
+        unlink($file_new);
+        my ($ncl) = length($newContent);
+        die "$ProgramName: Failed to write the content to '$File' (wb=$wb, len=$ncl, err:$!)\n";
+      }
     }
     close($FileHandle);
     # do the moving (should be atomic)
@@ -478,6 +492,7 @@ sub actualize() {
     unlink($file_old)
       or warn "$ProgramName: Failed to remove file '$file_old' ($!)\n";
   }
+  DEBUG and print STDERR "actualize: LinesCount=$LinesCount\n";
 }
 
 # return content from standard input