# even if file2 is a link to a directory. This option implies -f.
use Cwd;
+use POSIX; # for opendir and friends
$usage =
"usage: lns [flags] srcfile destfile\n".
"where: -a create symlinks with absolute path names\n".
" -f overwrite existing symlink at target location\n".
" -F like -f, but works even if target is link to dir\n".
+ " -r recursively construct a directory tree which\n".
+ " mirrors the source, with symlinks to all files\n".
" -v verbosely log activity (repeat for more verbosity)\n".
" -q suppress error messages on failure\n".
" also: lns --version report version number\n" .
"CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n" .
"SOFTWARE.\n";
-$abs=$force=$quiet=$verbose=$FILE=0;
+$abs=$force=$quiet=$verbose=$recurse=$FILE=0;
while ($_=shift @ARGV) {
last if /^--$/;
unshift (@ARGV, $_), last unless /^-(.*)/;
if ($opt eq "a") { $abs=1; }
elsif ($opt eq "f") { $force=1; }
elsif ($opt eq "q") { $quiet=1; }
+ elsif ($opt eq "r") { $recurse=1; }
elsif ($opt eq "v") { $verbose++; }
elsif ($opt eq "F") { $force=$FILE=1; }
else { die "lns: unrecognised option '-$1'\n"; }
if ($multiple) {
foreach $source (@ARGV) {
+ # We must path-normalise $source _before_ looking for the final
+ # filename component, to deal with the case of `lns . subdir'
+ # in which we want the link to be called subdir/<dirname> rather
+ # than subdir/. .
+ $source = &normalise($source);
$source =~ /^(.*\/)?([^\/]*)$/; # find final file name component
&makelink($source, "$target/$2"); # actually make a link
}
sub makelink {
local ($source, $target) = @_;
+ # Calculate the absolute path names of both source and target.
+ $source = &normalise($source);
+ $target = &normalise($target);
+
+ # If we're in Relative mode (the default), calculate the relative path
+ # name we will reference the source by.
+ $sourcename = $abs ? $source : &relname($source, $target);
+ my $donothing = 0;
+ my $recursing = $recurse && -d $source;
+ my $ok;
# If the target exists...
if (-e $target || readlink $target) {
- # If it's a symlink and we're in Force mode, remove it and carry on.
- if ($force && readlink $target) {
+ if ($recursing && -d $target) {
+ # If it's a directory and we're in recursive mode, just do nothing
+ # and work around it.
+ $donothing = 1;
+ } elsif ($force && readlink $target) {
+ # If it's a symlink and we're in Force mode, remove it and carry on.
unlink $target || die "lns: unable to remove link $target\n";
# Report that if in Verbose mode.
warn "lns: removing existing target link $target\n" if $verbose;
}
}
- # OK, now we're ready to do the link. Calculate the absolute path names
- # of both source and target.
- $source = &normalise($source);
- $target = &normalise($target);
-
- # If we're in Relative mode (the default), calculate the relative path
- # name we will reference the source by.
- $sourcename = $abs ? $source : &relname($source, $target);
-
- warn "lns: linking $source: $target -> $sourcename\n" if $verbose;
-
- # Make the link
- symlink($sourcename, $target) || die "lns: unable to make link to $target\n";
+ if ($recursing) {
+ # Make the directory.
+ if ($donothing) {
+ warn "lns: directory $target already exists, no need to create it\n"
+ if $verbose;
+ $ok = 1;
+ } else {
+ warn "lns: making directory $target\n"
+ if $verbose;
+ if (mkdir $target) {
+ $ok = 1;
+ } else {
+ warn "lns: unable to make directory '$target': $!\n";
+ }
+ }
+ # Now recurse into it.
+ if ($ok) {
+ my $dh = POSIX::opendir($source);
+ my @files = POSIX::readdir($dh);
+ my $f;
+ POSIX::closedir($dh);
+ foreach $f (@files) {
+ next if $f eq "." or $f eq "..";
+ &makelink("$source/$f", "$target/$f");
+ }
+ }
+ } else {
+ # Make the link.
+ warn "lns: linking $source: $target -> $sourcename\n" if $verbose;
+ symlink($sourcename, $target) || die "lns: unable to make link to $target\n";
+ }
}
sub normalise {
# segments.
local ($_) = @_;
+ warn "lns: path normalisation required on $_\n" if $verbose > 2;
+
# Make relative paths absolute.
$_ = getcwd() . "/" . $_ if !/^\//;
1 while s/^(.*)\/\.(\/.*)?$/$1$2/;
# Remove redundant slashes.
- s/\/+/\//;
+ s/\/+/\//g;
# Remove a trailing slash if present.
s/\/$//;
while (/^(.*)\/((\.|\.\.[^\/]+|\.?[^\/\.][^\/]*)\/\.\.)(\/.*)?$/)
{
my ($pre, $dir, $frag, $post) = ($1,$2,$3,$4);
- my $log = "transforming $target -> ";
+ my $log = " transforming $_ -> ";
if (-l "$pre/$frag") {
my $linktext = readlink "$pre/$frag";
if ($linktext =~ /^\//) { # absolute link
$_ = $pre . $post;
}
$_ = "/" if $_ eq ""; # special case
- $log .= "$target";
- warn "lns: $log\n" if $verbose > 1;
+ s/\/+/\//g; # remove redundant slashes again in case link text had any
+ $log .= "$_";
+ warn "lns: $log\n" if $verbose > 2;
}
# The only place where a ".." fragment might still remain is at
# the very start of the string, and "/.." is defined to be
# equivalent to "/".
- 1 while s/^\/\.\.\//\//;
+ 1 while s/^\/\.\.(\/(.*))?$/\/$2/;
+
+ warn "lns: path normalisation returned $_\n" if $verbose > 2;
return $_;
}
while (1) {
+ warn "lns: trying prefix '$prefix': looking for $target as prefix of $source\n" if $verbose > 1;
+
# If $target is _precisely_ $source, we are done.
if ($target eq $source) {
return "." if $prefix eq "";
# linking `a/b/c/foo' to `foo' then a simple relative link will
# work.)
if (substr($source, 0, 1 + length $target) eq "$target/") {
- return $prefix . substr($source, 1 + length $target); # skip the slash
+ warn "lns: found it\n" if $verbose > 1;
+ return $prefix . substr($source, 1 + length $target); # skip the slash
+ } elsif ($target eq "/") {
+ warn "lns: found it\n" if $verbose > 1;
+ return $prefix . substr($source, 1); # special case
}
# Otherwise, descend to "..".
~mdw / sgt / utils / blobdiff