--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/prog/07.pl	Tue Aug 24 21:30:47 2021 +0900
@@ -0,0 +1,31 @@
+# ファイル分割
+
+my $tmp = "pdf";
+my $buf0;
+for my $file (glob "_data03/*") {
+
+	open my $fi, '<', $file;
+	binmode($fi);
+
+	read($fi, $buf0, 4);
+
+	open my $fo, '>', $tmp;
+	binmode($fo);
+
+	my $buf;
+	while (read($fi, $buf, 1024)) {
+		print {$fo} $buf;
+	}
+	close $fo;
+
+	close $fi;
+
+	my $fn = substr $file, 1;
+	rename $tmp, $fn;
+}
+
+open my $f, '>', $tmp;
+binmode($f);
+print {$f} $buf0;
+close $fo;
+