Recent content by NewtownGuy

Hi, I read the man page in Ubuntu Server 10.04 for flock, but I still have questions. The man page gives an example: ( flock -s 200 -- code to execute under lock --- ) 200>/var/lock/mylockfile The man page says -s is a shared lock, or read lock, but the default is a write lock. Does the...

I knew this would introduce me to some new things... :-) I'm confused by wrapped commands and file descriptors. What lock file is used with a wrapped command ? If the writing program uses one locking method, do the reading programs have to use the same method ? If I use file descriptors, do the...

TO: Feherke Thank you for the many suggestions. I'm running bash 4.1.5. Since I'm running a version that supports mapfile, how should I use locks with mapfile ? How do I use locks to write files ? Do I use a loop that atomically checks and sets the lock, waits until it's not locked, then...

TO: feherke Thank you for your help. I need to process every file, of which there can be tens of thousands, in a folder. I get the file names with: ls $readPath -1 -S -r -all --time-style=long-iso --group-directories-first > $listFileName -- snip -- I then read that file into an array...

TO: Mike Thank you for your reply. How do I lock and unlock a file in Ubuntu 10.04 Server bash while I read it ? What do I do in the other program that may need to write to a locked file so no data is lost ? Does the other program have to check for a lock, buffer the data if locked, then...

I'm not sure if this is the right place for this question. I'm running Ubuntu Server 10.04 LTS. This machine is continuously acquiring data in real time and adding snippets of data to various of tens of thousands of files. From time to time, I have a bash program read all the files in turn and...

There's an /etc/X11 folder, but it only has xkb and Xsession.d in it. This is an embedded machine, so the graphics capability is built in. I works fine under Ubuntu 10.04. 'lspci' says it's a VGA compatible controller: Intel Corporation Atom Processor D2xxx/N2xxx Integrated Graphics Controller...

Forgot to mention... I turned on verbose in grub. The screen goes blank the instant it finishes booting. I tried uninstalling acpid -- which I need -- but it didn't make any difference, so I reinstalled it.

I'm going bananas ! I did a clean installation of Ubuntu 12.10 SERVER. I get the initial screen, but then it says "entering power save" and the screen goes black / blank. I can't turn on the screen for love or money. I know the machine is running because I can SSH into it. I tried changing the...

I found a dumb error in the surrounding code. Sigh...

I have a bash script that is supposed to process the ten last lines, or fewer in files with fewer than ten lines, of a text file. I use 'tail' to read these lines into a new text file, which I then read into an array. There's a problem when the file being read has fewer than ten lines. The...

I'm building a wireless access point using Ubuntu Server 10.04 LTS and an Atheros AR9287 wireless network interface card. I want to detect when mobile devices scan for wireless access points and I want to maximize the frequency with which they do so. I do not want to allow them to communicate...

OK... Traceroute does not do what I wanted it to do. So how do I get my public dynamic IP address without using an outside agent unless I can get into the DHCP client on my router ?

Hi Chris, I checked the manual for tracert (Laurie: tracert on Ubuntu is supposed to be the same as traceroute -I), but I still don't understand why it does not report my public IP address in the 15 or so hops it takes to get to the destination. I don't even see an IP address where the...

Hi Laurie, Yes, I get the correct public IP address when I go to the site. And yes, I get a file with the proper IP address when I do a simple wget. Cheers,