All Questions

16
votes
3answers
13k views

Full disk encryption with password-less authentication in Linux

I have a fairly standard disk encryption setup in Debian 5.0.5: unencrypted /boot partition, and encrypted sdaX_crypt that contains all other partitions. Now, this is a headless server installation ...
7
votes
1answer
495 views

Linux kernel 2.6 on ARM

I have compiled and installed the 2.6 kernel on an ARM board. I am using the ARM mini2440 board. I would like to know if there is already a way to access the General Purpose I/O port pins? Or will ...
46
votes
7answers
71k views

How can I get a formatted date for a UNIX timestamp from the command line

I have a UNIX timestamp and I'd like to get a formatted date (like the output of date) corresponding to that timestamp. My attempts so far: $ date +%s 1282367908 $ date -d 1282367908 date: invalid ...
6
votes
2answers
411 views

What files in /var need to have specific owners?

I accidentally wreaked unknown amounts of havoc on my web server by running sudo chown -R myuser:mygroup * .* in /var/www, not remembering that .* would include the parent directory (as ..). I ...
4
votes
3answers
1k views

How do major package managers differ?

It appears that the major package managers are (in no particular order) apt, yum, and pacman. But when it comes down to it, what is the difference? My understanding is that you can use any of them on ...
10
votes
1answer
325 views

What are you going to do with your OpenSolaris machines?

I have a file server running OpenSolaris (mainly for ZFS, which I really love), but since Oracle has abandoned it, I'm starting to think about what I'm going to do with the OS on that machine. ...
63
votes
4answers
33k views

Can't pipe into diff?

I wanted to be clever and compare a remote file to a local file without first manually downloading it. I can get the contents of the remote file by ssh user@remote-host "cat path/file.name" However,...
4
votes
3answers
391 views

Persist clipboard contents in vi

If I want to copy text from a file in vi to another file, I have to highlight the text, Control-Shift-C it, quit the first file, open the second, and then paste it via Control-Shift-V. It feels like ...
6
votes
2answers
2k views

Number of running processes show in top

The usual maximum number that I have seen in the "running" field displayed in top(1) is the number of logical CPUs installed in the system. However, I have observed that under Ubuntu 10.04 (not ...
98
votes
13answers
27k views

What is the benefit of compiling your own linux kernel?

What benefit could I see by compiling a Linux kernel myself? Is there some efficiency you could create by customizing it to your hardware?
15
votes
2answers
6k views

Is there a way to intercept interprocess communication in Unix/Linux?

For intercepting/analyzing network traffic, we have a utility called Wireshark. Do we have a similar utility for intercepting all the interprocess communication between any two processes in Unix/...
83
votes
9answers
303k views

Is there a way to see details of all the threads that a process has in Linux?

For Windows, I think Process Explorer shows you all the threads under a process. Is there a similar command line utility for Linux that can show me details about all the threads a particular process ...
21
votes
9answers
39k views

Ensure a process is always running

I started hosting sites a while back using Cherokee. For external sources (FastCGI, etc) it has an option to launch the process if it can't find one running on the designated socket or port. This is ...
15
votes
3answers
2k views

Can I limit a user (and their apps) to one network interface?

As the title really. I've actually got two scenarios to apply this: Multiseat Desktop: two network connections both with internet gateways and two accounts doing bandwidth-intensive tasks on each. I ...
4
votes
3answers
658 views

Something like pwgen-win for linux?

Is there some kind of pwd generator for Linux that has a nice GUI and options like this one for Windows? I know that there is pwgen, but as far as I know it does not support mouse/keyboard entropy and ...
11
votes
2answers
3k views

the slash (/) after a directory name on shell commands

I have a little question here. If I have two files, say filea and fileb, mv filea fileb would delete fileb rename filea to fileb Then if I have two directories, say dira and dirb, mv dira dirb ...
8
votes
4answers
4k views

How to best encrypt and decrypt a directory via the command line or script?

I have a directory of text files under bazaar version control and keep a copy (a branch, actually) on each of my machines. I want to encrypt and unencrypt the directory via the command line. Ideally, ...
7
votes
2answers
10k views

How do I add PC BSD / FreeBSD to Grub 2 boot loader?

I have Ubuntu 10.04 installed as my primary operating system, and I installed PC BSD in a different partition: /dev/sda4 without installing it's boot loader. I figured out that I need to edit /etc/...
2
votes
1answer
268 views

How can I figure out why gnome-panel is frequently misbehaving?

On my system (Debian Lenny AMD64), gnome-panel seems to act up now and again. I've not found a way to force it to happen, but it seems to be related to launching processes. Basically, I launch some ...
16
votes
4answers
1k views

Linux adoption path for a .NET developer [closed]

I am a .NET C# programmer, I love the .NET stack. I have tried Linux several times but every time I got put off as I could not do anything on it .. (like program for it or on it). Ever since Mono was ...
2
votes
3answers
513 views

Weekly cron job to save list of installed packages

I am having trouble figuring out how to set up my first cron job. I simply want to run this command once every week: dpkg -l > ~/Dropbox/installed_packages My /etc/crontab file contains the line ...
13
votes
5answers
2k views

Best way to do full disk encryption?

I have got a bit lost and am not sure which technology to choose for full disk encryption. It is hard to tell if the information out there is still up to date. Is there a current best practice ...
10
votes
3answers
16k views

How to make a folder private?

I'm using Ubuntu with several users and I want to make folders viewable just for a specific user. Any idea how to do it?
5
votes
6answers
5k views

Is there a (light-weight) replacement for `rxvt-unicode`?

I am currently using rxvt-unicode as a terminal emulator. Since I also like the configurability of terminal emulators from GNOME and KDE, I wonder whether there is some kind of replacement for rxvt-...
123
votes
9answers
84k views

How to determine where an environment variable came from

I have a Linux instance that I set up some time ago. When I fire it up and log in as root there are some environment variables that I set up but I can't remember or find where they came from. I've ...
1
vote
1answer
1k views

How can I call a .NET web service from PHP?

The web service could be a SOAP asmx or a WCF Service. Assumption here is that the IIS on Windows is serving the web-service and Apache on Linux with PHP 5.3 consuming it.
0
votes
3answers
544 views

FreeBSD: Which branch is supported for longer?

Can someone help explain the FreeBSD support policy? I'm looking at http://security.freebsd.org/#sup , which says: Branch Release Type Release Date Estimated EoL RELENG_6 ...
3
votes
3answers
827 views

Updating FreeBSD 8.0 to 8.1 (methods and policy)

I have 8.0-RELEASE-p4 + few ports installed. I wonder wheather I should update to 8.1. How long is 8.0 supported? How to update the system? I couldn't find anything about it in handbook. SOLUTION (...
370
votes
7answers
40k views

How can I find the implementations of Linux kernel system calls?

I am trying to understand how a function, say mkdir, works by looking at the kernel source. This is an attempt to understand the kernel internals and navigate between various functions. I know mkdir ...
13
votes
4answers
31k views

passwordless ssh for another username?

I want to do a passwordless ssh connection for a subversion project. Right now I'm using ssh+svn, and it's a little annoying, because I have to type the password any time I want to transact with the ...
17
votes
8answers
13k views

What are some common tools for intrusion detection? [closed]

Please give a brief description for each tool.
12
votes
4answers
10k views

Downsides of umask 077?

What are the cons, for having a restrictive umask of 077? A lot of distros (I believe all, except Red Hat? ) have a default umask of 022, configured in /etc/profile. This seems way too insecure for a ...
3
votes
1answer
3k views

Is there an XML file editor for Linux with grid view support?

I have been using Altova XML Editor on Windows for a long time. It has a wonderful feature that lets you view XML files in "grid view." This makes life easy when reading very complex XML. My question ...
2
votes
2answers
4k views

How to set up file permissions/ownership for FTP/Apache/PHP on CentOS

I have basic understanding of chmod and CentOS file permissions. 777 stands for 111111111 and rwx for each root, group, user, etc. What I can't get my head around is setting up Apache, FTP and PHP to ...
3
votes
3answers
2k views

Are there rc logs in arch?

One of my processes is failing to start fairly early in the boot process (I suspect mdadm and I suspect that it's just taking longer than the rc script allows for) but I can't quite catch/see it ...
248
votes
10answers
104k views

What is the real difference between “apt-get” and “aptitude”? (How about “wajig”?)

I know that both apt-get and aptitude are command line package management interfaces on Debian derived Linux, with different options, but I'm still somewhat confused. Under the hood, aren't they ...
3
votes
1answer
355 views

Learning about iptables: Is this Slicehost example any good?

In preparation to eventually launch my first website, I've been playing with Ubuntu Lucid Server in a VM on my WinXP machine. I've been alternating between the Linode and Slicehost tutorials/articles ...
13
votes
3answers
2k views

What does it mean when code is executed in [kernel|user] mode?

What does it mean when code is executed in kernel or user mode?
37
votes
7answers
5k views

How could I remember how to use redirection?

I know what program > /dev/null 2>&1 does. It redirects the output to /dev/null and 2>&1 means to redirect the error output in the same place where the output is sent. My ...
8
votes
9answers
514 views

What is/are the standard CLI program(s) to manage users and groups?

As the title says, I'm basically asking about user management from the command line (e.g. on a system where there are no graphical tools available). In the past I've used several different programs to ...
19
votes
7answers
19k views

What distributions have rolling releases? [closed]

I was browsing DistroWatch and was looking for a list of distributions that offer rolling releases and a little bit more about them. However, it doesn't seem to be possible to select only the rolling ...
49
votes
7answers
15k views

Software developer switching from Linux to OS X, what are the gotchas?

I have used Ubuntu/Fedora/Red Hat/Suse but haven't used OS X at all. If I have to start using OS X regularly, what are the things I should look out for? Tools I use are GNU tool chain, C++/Boost, etc....
39
votes
8answers
52k views

Can we get compiler information from an elf binary?

Is there some chance to know how a binary was built, under Linux? (and or other Unix) Compiler, version, time, flags etc... I looked at readelf and couldn't find much, but there might be other ways ...
0
votes
3answers
2k views

How can I (and should I) use my Linux file server as a Time Machine backup server for my Macs?

I have two Macs that I'd like to start backing up using Time Machine, but all of my storage is attached to my Linux file server. How can I use my Linux file server (which happens to be running Ubuntu ...
9
votes
1answer
3k views

How do I get a long listing for a single directory?

I want to see a long listing for a single directory. When I type ls -lha, I see this: drwxrwxr-x 4 username groupname 4.0K 2010-08-05 09:55 files drwxrwxr-x 7 username groupname 4.0K 2010-08-05 14:...
43
votes
3answers
27k views

Where does Mac OS X come from?

Discussing with Mac owners, I got several versions of where Mac OS X comes from. It is known to have some root in BSD, but how much, and where? Some say that Mac OS X has a FreeBSD kernel, with all ...
4
votes
3answers
453 views

Any alternative of “man -a” on UNIX?

man -a <xyz> opens all the man pages one by one which contain xyz. On my unix servers man -a <xyz> doesn't work. Is there any alternative for this on unix? EDIT: I am on HP-UX. Following ...
49
votes
9answers
46k views

Why put things other than /home to a separate partition?

So recently a Debian 5.0.5 installer offered me to have separate /usr, /home, /var and /tmp partitions (on one physical disk). What is the practical reason for this? I understand that /home can be ...
8
votes
5answers
12k views

'kill java' doesn't kill java

I am running debian right now and sometimes I need to kill java manually from the terminal, but when I try kill #pid# or pkill java nothing happens. No console output (ok, that's normal) and java is ...
37
votes
6answers
16k views

How does a unix or linux system work? [closed]

I would like to know how the OS works in a nutshell: The basic components it's built upon How those components work together What makes unix UNIX What makes it so different from other OSs like ...

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