From: Michele Andreoli ([email protected])
Date: Sun May 07 2000 - 17:06:40 CEST
Hi, friends.
I uploaded release 9r1b. Only mulinux.tgz and DOSTOOLS.zip changed.
I added in DOSTOOLS newly the boot.bat script, able to start muLinux
a the top of DOS.
I added also a new command/server: vcm, virtual console monitor. It is
only a 'poke' demo. This simple script is able to poke string at
fixed location in the video-ram. It shows, in the top-right corner of console,
time/date, free memory, uptime and received/trasmitted packets
across Ethernet interface. It is enabled via Setup/server.
I think, vcm is a pedagogical demo and can inspire other similar tricks
to someone, for example games, virus, etc...
Unfortunately, it isn't able to change colors using 'poke': a colored
monitor should looks better. If someone find a workaround, please
let me know.
The new 'poke' is able to insert strings, not only single bytes.
Example:
# poke -c /dev/vc1 10 'ciao' 50 'mondo'
put the string 'ciao' in the file /dev/vc1 (the console #1), starting
from byte 10th, and the string 'mondo', starting from byte 50th.
2 cent Tip 1
-------------
Obvioulsy, a command like:
# poke /dev/hda1 1 128 2 35 3 255 ....
may reprogram the Master Boot Sector of the primary hard-disk.
2 cent Tip 2
------------
Does someone on the list remember old BASIC listing, with DATA functions,
able to move code around the RAM? Well, now you can realize similar
things using a single shell program:
Using 'poke':
#!/bin/sh
PGM="1 128 2 35 ... (other 4-5000 pairs)"
poke /tmp/cmd $PGM
exec /tmp/cmd
Using hexd (the new one, from A. Costa)
#!/bin/sh
PGM="6162002e737472746162002e736873747274 ...."
echo $PGM | hexd -d > /tmp/cmd
exec /tmp/cmd
How to fill PGM? Easy:
# PGM=`cat /bin/my_command | hexd -x`
2 cent Tip 3 : programs uncompressed on-the-fly
----------------------------------------
prepare PGM
# PGM=`cat /bin/my_command | hexd -x | gzip -c`
#!/bin/sh
PGM="6162002e737472746162002e736873747274 ...."
echo $PGM | gzip -dc | hexd -d > /tmp/cmd
chmod +x /tmp/cmd
exec /tmp/cmd
Mmmm ... there is some limit on the variable storage in ash?
Michele
-- I'd like to conclude with a positive statement, but I can't remember any. Would two negative ones do? -- Woody Allen --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
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