backup: First version of restore script

backup-tar/restore.pl

+#!/usr/bin/env -S perl -T
+
+use warnings;
+use strict;
+
+use File::Spec::Functions ( "catfile", "catdir", "file_name_is_absolute", "splitdir" );
+use Scalar::Util ( "tainted" );
+
+$ENV{PATH} = "/usr/local/bin:/usr/bin:/bin";
+my $thrs = 1;
+if ( `nproc` =~ /^([0-9])$/ ) {
+    $thrs = int( $1 / 4 );
+    $thrs = 1 if $thrs <= 0;
+    $thrs = 8 if $thrs > 8;
+}
+
+sub usage {
+    my ( $stream ) = @_;
+    $stream = *STDERR unless defined $stream;
+    print $stream "backup-restore MACHINE DATE PATH\n"
+}
+
+if ( @ARGV < 3 ) {
+    usage(*STDOUT);
+    exit 1;
+}
+
+my $machine;
+if ( (shift @ARGV) =~ m|^([^/ ]*)$| ) {
+    $machine = $1;
+} else {
+    print STDERR "Machine must be a machine name only, not a path\n";
+    usage;
+    exit 2;
+}
+my $date;
+if ( (shift @ARGV) =~ /([0-9]+-[0-9]+-[0-9]+)/ ) {
+    $date = $1;
+} else {
+    print STDERR "Date must be in YEAR-MOONTH-DAY format\n";
+    usage;
+    exit 2;
+}
+my @paths = ();
+for my $p ( @ARGV ) {
+    if ( $p =~ m|^(/.*)$| ) {
+        push( @paths, $1 );
+    } else {
+        print STDERR "Expected absolute path but got $p\n";
+        usage;
+        exit 2;
+    }
+}
+
+print "$machine $date @paths\n";
+
+my $full;
+my @weekly = ();
+my @daily = ();
+
+my $namematch = qr/^([0-9]+-[0-9]+-[0-9]+)[.](daily|weekly|full)[.](.*)$/;
+
+opendir( my $dir, catdir("/backup-tar", $machine ) ) or die $!;
+my @backups = sort( grep { /$namematch/ } readdir( $dir ) );
+for my $backup ( @backups ) {
+    $backup =~ /$namematch/;
+    $backup = "$1.$2.$3";
+    my $path = catfile( "/backup-tar", $machine, $backup );
+    my $from = $1;
+    my $type = $2;
+    last if $from gt $date;
+
+    if ( $type eq "full" ) {
+        $full = $path;
+        @weekly = ();
+    } elsif ( $type eq "weekly" ) {
+        push( @weekly, $path );
+        @daily = ();
+    } else {
+        push( @daily, $path );
+    }
+}
+
+my @to_restore = ( $full, @weekly, @daily );
+
+for my $backup ( @to_restore ) {
+    print $backup . ": " .  tainted( $backup ) . "\n";
+    system( "tar", "--extract", "--auto-compress", "--incremental", "--xattrs",
+            "--acls", "-vv", "-T$thrs", "-f$backup", "--", @paths ) == 0
+        or die "extract of $backup failed $?";
+}