Rewrite uploadb.py in perl

I know, this is silly, but I'm moving tools to something a bit closer to the
system. I consider perl to be more system-like than python for a simple reason:
perl is part of the OpenBSD base system and python is not.

Also, I'm learning perl and using this as an opportunity.

tools/uploadb.pl

@@ -0,0 +1,79 @@
+#!/usr/bin/perl
+# Push specified file to specified device **running the BASIC shell** and verify
+# that the sent contents is correct.
+use strict;
+use Fcntl;
+
+if (@ARGV != 3) {
+    print "Usage: ./uploadb.pl device memptr filename\n";
+    exit 1;
+}
+
+my ($device, $memptr, $fname) = @ARGV;
+
+if (hex($memptr) >= 0x10000) { die "memptr is out of range"; }
+
+if (! -e $fname) { die "${fname} does not exist"; }
+my $fsize = -s $fname;
+my $maxsize = 0x10000 - hex($memptr);
+if ($fsize > $maxsize) { die "File too big. ${maxsize} bytes max"; }
+
+my $fh;
+unless (open($fh, '<', $fname)) { die "Can't open $fname"; }
+
+my $devh;
+unless (sysopen($devh, $device, O_RDWR|O_NOCTTY)) { die "Can't open $device"; }
+
+sub sendcmd {
+    # The serial link echoes back all typed characters and expects us to read
+    # them. We have to send each char one at a time.
+    my $junk;
+    foreach my $char (split //, shift) {
+        syswrite $devh, $char;
+        sysread $devh, $junk, 1;
+    }
+    syswrite $devh, "\n";
+    sysread $devh, $junk, 2; # send back \r\n
+}
+
+sendcmd("m=0x${memptr}");
+
+my $rd;
+sysread $devh, $rd, 2; # read prompt
+
+# disable buffering
+$| = 1;
+
+while (sysread $fh, my $char, 1) {
+    print ".";
+    for (my $i=0; $i<5; $i++) { # try 5 times
+        sendcmd("getc");
+        syswrite $devh, $char;
+        sysread $devh, $rd, 2; # read prompt
+        sendcmd("print a");
+        my $s = "";
+        while (1) {
+            sysread $devh, $rd, 1;
+            if ($rd !~ /\d/) { last; }
+            $s .= $rd;
+        }
+        sysread $devh, $rd, 3; # read prompt
+        if ($s == ord($char)) {
+            last;
+        } else {
+            if ($i < 4) {
+                print "Mismatch at byte ${i}! ${s} != ${ord($char)}. Retrying.\n";
+            } else {
+                die "Maximum retries reached, abort.\n";
+            }
+        }
+    }
+    sendcmd("poke m a");
+    sysread $devh, $rd, 2; # read prompt
+    sendcmd("m=m+1");
+    sysread $devh, $rd, 2; # read prompt
+}
+
+print "Done!\n";
+close $fh;
+close $devh;

tools/uploadb.py

@@ -1,79 +0,0 @@
-#!/usr/bin/env python3
-
-# Push specified file to specified device **running the BASIC shell** and verify
-# that the sent contents is correct.
-
-import argparse
-import os
-import sys
-
-def sendcmd(fd, cmd):
-    # The serial link echoes back all typed characters and expects us to read
-    # them. We have to send each char one at a time.
-    if isinstance(cmd, str):
-        cmd = cmd.encode()
-    for c in cmd:
-        os.write(fd, bytes([c]))
-        os.read(fd, 1)
-    os.write(fd, b'\n')
-    os.read(fd, 2)  # sends back \r\n
-
-
-def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument('device')
-    parser.add_argument('memptr')
-    parser.add_argument('filename')
-    args = parser.parse_args()
-
-    try:
-        memptr = int('0x' + args.memptr, 0)
-    except ValueError:
-        print("memptr are has to be hexadecimal without prefix.")
-        return 1
-    if memptr >= 0x10000:
-        print("memptr out of range.")
-        return 1
-    maxsize = 0x10000 - memptr
-    st = os.stat(args.filename)
-    if st.st_size > maxsize:
-        print("File too big. 0x{:04x} bytes max".format(maxsize))
-        return 1
-    fd = os.open(args.device, os.O_RDWR)
-    with open(args.filename, 'rb') as fp:
-        fcontents = fp.read()
-    sendcmd(fd, f'm=0x{memptr:04x}')
-    os.read(fd, 2) # read prompt
-
-    for i, c in enumerate(fcontents):
-        c = bytes([c])
-        print('.', end='', flush=True)
-        for _ in range(5): # try 5 times
-            sendcmd(fd, 'getc')
-            os.write(fd, c)
-            os.read(fd, 2) # read prompt
-            sendcmd(fd, 'print a')
-            s = b''
-            while True:
-                r = os.read(fd, 1) # putc result
-                if not r.isdigit():
-                    break
-                s += r
-            os.read(fd, 3) # read prompt
-            if int(s) == c[0]:
-                break
-            else:
-                print(f"Mismatch at byte {i}! {c} != {r}. Retrying")
-        else:
-            print("Maximum retries reached, abort")
-            return 1
-        sendcmd(fd, 'poke m a')
-        os.read(fd, 2) # read prompt
-        sendcmd(fd, 'm=m+1')
-        os.read(fd, 2) # read prompt
-    print("Done!")
-    os.close(fd)
-    return 0
-
-if __name__ == '__main__':
-    sys.exit(main())