./bin/sh : Permission denied

OliB · 05-29-2008, 03:05 AM

Quote:

Originally Posted by jschiwal

However, this brings back memories about using the Amiga computer. It was a multiprocessing OS which originally used the 68000 processor & didn't have an MMU. The only fixed address that a program would have was $4 which contained a pointer to indirectly find the real address. All addressing was relative and the programs needed to be written reentrant and moveable.

Oh my god I'm certainly too young to know this

I have heard of 68k processors but only on Wikipedia

I'm only 21 y.o. and I started programming embedded devices few months ago!

Quote:

Originally Posted by jschiwal

I think that you may be correct in that your version of BusyBox may have been built with some built in commands left out. Often a project will have configuration options whether to include or exclude certain features.

I already know that my Busybox was in version 1.00 built 2008-01-17. But I admit I never had the idea to ask my friend Google what does he think

Then, what I've found confirm what I thought (and as you said): A version of Busybox has been rebuilt specially for my board

The directories show there http://www.nslu2-linux.org/wiki/Optware/BusyBox
are different from mine. Ex: In Bb 1.0 there should be 'chgrp' but there is not this command in mine.
I tried 'help' :

Code:

# help

Built-in commands:
-------------------
    . : break cd continue eval exec exit export help login newgrp
    read readonly set shift times trap umask wait

I don't know why these commands are displayed, because some of them are unavailable like 'newgrp' (it may be an old txt help file from previous versions not kept up to date).
Well, I also tried to type 'msh'. As a result, I obtained a new console line (starting with #) and nothing else. A new shell was opened in my shell and I had to type exit to come back...
Then, I tried something crazy

I typed 'busybox' and that's what it answered me :

Code:

# busybox
BusyBox v1.00 (2008.01.17-16:15+0000) multi-call binary

Usage: busybox [function] [arguments]...
   or: [function] [arguments]...

    BusyBox is a multi-call binary that combines many common Unix
    utilities into a single executable.  Most people will create a
    link to busybox for each function they wish to use, and BusyBox
    will act like whatever it was invoked as.

Currently defined functions:
    [, basename, busybox, cat, chmod, clear, cp, cut, date, df, dmesg,
    du, echo, env, expr, false, find, free, freeramdisk, grep, gunzip,
    gzip, halt, head, hostname, hwclock, ifconfig, insmod, kill, killall,
    ln, ls, lsmod, mkdir, mkfifo, more, mount, msh, mv, ping, ps,
    pwd, reboot, renice, rm, rmdir, rmmod, route, sed, sh, sleep,
    stty, sync, tail, tar, test, touch, traceroute, true, umount,
    uname, uptime, vi, xargs, zcat

Thanks to this command, I can now understand that busybox is only a link to other executables.
Now, I can see there is noting to create new accounts for new users.

This embedded device is a low power (3 Watt when fully loaded) intelligence capable of acquiring data from RS232 inputs, calculating new instructions, and sending new commands on RS232 outputs to a power system. I wanted to create user accounts to allow someone using the device to see in real-time what was coming on inputs and going output.
This is not possible with this manufacturers' board. So I will create functions to analyze what is streaming and write it on a HTML report.

PS: "IHMO" = ...? (me =

)

linuxlover.chaitanya · 05-29-2008, 03:13 AM

"IHMO"= In My Humble Opinion. ( I guess this is correct )

jschiwal · 05-29-2008, 10:12 AM

I guess you don't remember the VIC20 & C-64 with the 6502 processor.

The 8 bit processors were easy to learn assembler language on. I started with the VIC-20. I had a Commodore 64 when there was a 64 Minutes report on the WWII Enigma machine. I picked up a book on codes & cyphers. It had sample programs, but they were written in Apple Basic. There was a command ("explode" IIRC) that would break a string into a character array. I wrote an extension in assembler that added this command to C64's basic.

I ended up writing a program that would use a password to seed the PRNG and xor'ed the psuedo-random stream with the message. Decoding the message used the same program, because if you XOR a number twice you get the original. This wasn't from the book.

I actually used a device (Chyron II) that had magnetic core memory. This is were the name of "core dump" came from. If a program crashed, early Unix systems would dump the contents of the magnetic "core" memory.

OliB · 05-30-2008, 09:42 AM

Quote:

Originally Posted by jschiwal

I guess you don't remember the VIC20 & C-64 with the 6502 processor.

Right

I can see you have a good (and various) experience in programming, on several platforms!

I think this topic is now closed, and I have found what I wanted. I would like to thank you all for your help and specially jschiwal for the time he accorded to help me! Thank you and keep helping people as you do because we need people like you!

Person_1873 · 06-02-2008, 02:59 AM

i remembered seeing it on the gentoo install docs

Code:

# useradd -m -G users,wheel,audio -s /bin/bash username
# passwd username
Password: (Enter the password for username)
Re-enter password: (Re-enter the password to verify)

hope tis helps

whoops, forgot to read the rest of the post, i was under the impression that you were running a full linux distro on your device.