25 December 2007

desktop Ubuntu

I recently converted my laptop from CentOS 5 to Ubuntu 7.10 and liked the change. So I did the same to my main desktop at home this weekend. Naturally, there were a few bumps in the road. Over the next several days I'll be posting about some of them.

But first, a couple of annoyances.

Ubuntu likes to beep. It rings the system bell a lot more than CentOS seemed to do: tab completion at the bash prompt, unsuccessful page text searches in Firefox, trying to go past the end of the file in vim, etc. It really enjoyed beeping at me, and putting set bell-style none in ~/.inputrc didn't help much.

It turns out to be a kernel module. A post in Dell's Linux desktop forums suggested modprobe -r pcspkr, and that worked right away. The post also suggests putting blacklist pcspkr in a file in /etc/modprobe.d to make the change permanent (I haven't rebooted yet, but I figure that oughtta do it.)

The other annoyance is that Ubuntu's grep isn't compiled with libpcre support (that's the Perl-compatible regular expression library). One of the bash scripts I use for backups has a grep -P in it. The -P options tells grep to regard the search pattern as a Perl-style regex. This gives the following charming error message:

The -P option is not supported

Someone else noticed this and filed a bug report. Looks like the Ubuntu developers aren't interested in fixing it in this version. Someone suggested installing the pcregrep package, but this has a few problems:
  1. the binary is installed as /usr/bin/pcregrep
  2. pcregrep doesn't have the same performance or options as grep
  3. oddly, pcregrep doesn't accept the -P option (you'd think it would just ignore it)
So pcregrep is hardly a drop-in replacement for grep, even if you rename the binary to /bin/grep.

As it happens, I got lucky. My the regex in my bash script is dull enough that I was able to replace grep -P with egrep. But if you use something more sophisticated, you'll have a harder time of it.

But all in all, I'm enjoying my shiny new Ubuntu installation. I'll be back later to yammer on about using udev, fetchmail, iptables, and maybe some other stuff in Ubuntu.

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