Linux refers to the family of Unix-like computer operating systems using the Linux kernel. If your question is about a certain distribution only, use a more specific tag.

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What does the dot mean at the end of `-rw-r--r--`? How do you set it with `chmod`?

I see that some of the files in my directories under Linux have a . at the end of the permissions listing. What does the dot mean at the end of -rw-r--r--? How do you set it with chmod?
36
votes
1answer
23k views

logrotate configuration file syntax - multiple wildcard entries possible?

Since the man page doesn't answer my question and I don't want to force a rotation cycle, I decided to ask the question here. The man page for logrotate gives the following example: ...
36
votes
5answers
16k views

How can a linux kernel be so small?

An ordinary stable 3* kernel is about 70 mb now. But there are little linux distributions of 30-10 mb with software and other stuff running out of the box. How can the linux kernel be so small in ...
36
votes
2answers
19k views

Why is “/dev/rdisk” about 20 times faster than “/dev/disk” in Mac OS X

According to the rasbery pi documentation, You can load your OS to a flash card with either /dev/disk or /dev/rdisk. rdisk stands for raw disk. /dev/disk is a block level device, why would rdisk ...
36
votes
11answers
14k views

What's a good solution for file-tagging in linux?

I've been looking for a way to tag my files and search/filter them based on those tags. Here are my (updated) requirements : any file readable by the user can be tagged freely a user can search ...
36
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4answers
9k views

How can I log all process launches in Linux

I would like to get a log of all processes that are launched with the time that they were launched and the arguments they were launched with. Is this possible in Linux?
35
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8answers
124k views

How to upload one file by FTP from command line?

I need to upload a single file to FTP server from Ubuntu. This operation should be done in a script (in non-interactive mode). What is the right syntax for ftp? I'm trying this, to no avail: $ ftp ...
35
votes
4answers
9k views

Linux equivalent command for “open” command on Mac/Windows?

Coming from Mac OS X, you can type: $ open yourfilehere.txt and your file will open just as if you had opened it from Finder. On Windows, one can type: > start yourfilehere.txt and it will ...
35
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3answers
2k views

Say`vimrc`or `screenrc`, what does the `rc` mean?

What does the rc mean?
35
votes
3answers
18k views

How do I execute multiple commands when using find?

I'm trying to run multiple commands on things I have found, how can I achieve this? find . -exec cmd1; cmd2 does not seem to work; it instead runs cmd2 after cmd1 has been executed on every file.
35
votes
4answers
3k views

Palindrome passwords disallowed—why?

I tried to change a Linux password to "sitonapotatopanotis" and got this error: BAD PASSWORD: is a palindrome Why does this rule exist?
34
votes
12answers
4k views

How do I remove a file in Linux whose name looks like it's ONLY a hyphen, as in “-”

I've tried rm -- - rm "-" rm "\-" rm \- Gave Perl a shot ~$ perl -e '$junk = glob("-"); chomp $junk; print "$junk\n"; `rm $junk`;' - rm: cannot remove `-': No such file or directory ...and... ...
34
votes
13answers
49k views

In Google Chrome on Linux, where is the flv if not in /tmp?

I like to keep videos because I like buffering them and then playing them back-to-back in my media player, I want to be able to stop/restart my browser without losing all the buffered video, and ...
34
votes
5answers
6k views

What is the equivalent of Linux's “~” (tilde) in Windows?

In Linux, we can go to the user home by entering the tilde (~) character after cd: cd ~ How to do the same in Windows? Each time, I need to type: cd C:\Document and Settings\freewind That's too ...
34
votes
6answers
19k views

How do I get ls --color=auto to work on Mac OS X?

I'm trying to move my bash configuration from Ubuntu to Mac OS X and it looks like ls is slightly different. For instance, it won't accept the --color option. How do I get this to work?
34
votes
3answers
16k views

Set background image in xmonad

I have just switched from Fluxbox to giving xmonad a go, and I am definitely liking it. However, the one thing I haven't managed to do is to change my desktop background. I am using Ubuntu 8 (uh, ...
34
votes
11answers
114k views

PuTTY Network Error: Software caused connection abort

I have a strange problem: When I'm using PuTTY with SSH connecting to a Linux server hosted in VMware on my local Windows 7, I often get the error saying "Network error: Software caused ...
33
votes
15answers
16k views

What is Gnome / KDE etc?

I have been on Windows my entire life. Without getting too technical, what are these things? When I search on the net, I get some technical results. I simple do not understand what these things are! ...
33
votes
2answers
4k views

How come one user can delete another user's 755 files?

I have a backup upload script that scp’s files to another server using the user upload. Another script on the target server then chown’s these to another user and sets the file mode to 755. If I then ...
33
votes
3answers
43k views

How can I create a non-login user?

I'd like to create a user and a group both called subversion on a RHEL 5 system. I looked at the man page for useradd and I guess the command would be just be... useradd subversion However, not ...
33
votes
8answers
56k views

How to auto detect text file encoding?

There are many plain text files which were encoded in variant charsets. I want to convert them all to UTF-8, but before running iconv, I need to know its original encoding. Most browsers have an ...
33
votes
3answers
11k views

Can a process be frozen temporarily in linux?

I was wondering if there is a way to freeze any process for a certain amount of time? What I mean is that: is it possible for one application (probably running as root) to pause the execution of ...
33
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3answers
89k views

How does one change user's home directory in Ubuntu 9.04?

Does anyone know how I might change my home directory in the shell please?
33
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5answers
17k views

How to use different network interfaces for different processes?

I have two network interfaces on a Linux PC, and I need to manually set the interface that a given process will use. The program (Twinkle softphone) does not have a similar option, so I believe that ...
33
votes
8answers
7k views

How do you track which packages were installed on Ubuntu (Linux)?

(This question is very similar to 10458. It was suggested that Fedora and Ubuntu/Debian are different enough to warrant different answers.) As I use any Ubuntu setup I gradually install a number of ...
33
votes
1answer
27k views

How do file permissions apply to symlinks?

Let's say you have this structure: + directory -- file1 -- file2 -- file3 -> /tmp/file3 file3 is a link to another file3 somewhere else on the system. Now let's say I chmod 777 the directory ...
32
votes
3answers
3k views

Have a file named ~ (tilde) in my home-directory

I just noticed that I have a file called ~ in my ~-directory. $ ls -la ~ ... -rw-r----- 1 x1 x1 733962240 Mar 1 17:55 ~ ... Any idea how I can mv or rm it?
32
votes
4answers
94k views

How do I exit an SSH connection?

I’m connecting to a server via SSH to send a message to a socket server using a command like: ssh 181.169.1.2 -p 5566 After the connection is established and I write the message and send it I ...
32
votes
9answers
22k views

Linux: Compare Directory Structure Without Comparing Files

What is the best and simplest way to compare two directory structures without actually comparing the data in files? This works fine: diff -qr dir1 dir2_ But it's really slow because it's comparing ...
32
votes
5answers
52k views

How to determine available free space on Ubuntu?

I am in a situation where I am getting an error when I try to save a file to my Ubuntu server via ssh. It says there isn't any available space left. I don't know how that can be true. What should I do ...
32
votes
13answers
23k views

Is there a way to display a countdown or stopwatch timer in a terminal?

How can I display a real-time countdown timer on the Linux terminal? Is there an existing app or, even better, a one liner to do this?
32
votes
6answers
59k views

Bash script to delete files older than x days with subdirectories

I'm trying to delete a ton of files older than x days. Now I have a script to do that find /path/to/files* -mtime +10 -exec rm {} \; But this will also delete the subdirectories. There are a ton ...
32
votes
4answers
84k views

How to update Google chrome in Ubuntu?

How to update Google chrome in Ubuntu?
32
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2answers
4k views

How urgent is a *** System restart required *** for security?

To learn a bit of server administration I've set up a simple Ubuntu 14.04 server on which I run a personal website. I've set it to automatically install security updates, but leave out the other ...
32
votes
3answers
13k views

Does rm -f follow symbolic links?

I have a directory like this: $ ls -l total 899166 drwxr-xr-x 12 me scicomp 324 Jan 24 13:47 data -rw-r--r-- 1 me scicomp 84188 Jan 24 13:47 lod-thin-1.000000-0.010000-0.030000.rda ...
31
votes
3answers
15k views

Convert a PDF to greyscale on the command line in FLOSS?

I have a colour PDF file, and I'm going to print it out and then photocopy it in black and white. I'd like to know what it's like in B&W before photocopying it. Is it possible to 'greyscale' a PDF ...
31
votes
4answers
78k views

How do you set a password for transmission-daemon, the BitTorrent client server?

The config file is ambiguous, and keeps getting overwritten when you restart the daemon in Debian, anyway. In /etc/transmission-daemon/settings.json, there are these options: rpc-username ...
31
votes
2answers
5k views

Slight delay when switching modes in vim using tmux or screen

Switching to and from insert mode in Vim is no longer instantaneous since I use tmux. After pressing Esc in insert mode, it takes a noticeable amount of time to actually get out of insert mode. After ...
31
votes
1answer
51k views

Linux unzip command: Option to force overwrite?

I am writing a shell script that unzips a ZIP file into an existing hierarchy of files, potentially overwriting some of the files. The problem is that the unzip command asks for confirmation: replace ...
31
votes
3answers
3k views

Can history files be unified in bash?

I routinely run multiple screen sessions on my Linux desktops and servers. A problem with this is that when I grep through my command history, I find I issued a command in a different session, and ...
31
votes
4answers
9k views

Two keyboards on one computer. When I write with A i want a US keyboard layout, when I use B i want Swedish. Possible?

I have a laptop which I use an external keyboard with. When I type using the external keyboard I want to use a US keyboard layout, since that's the type of external keyboard I have. On the other hand, ...
31
votes
8answers
8k views

How can I merge the gnome clipboard and the X selection?

I'm constantly frustrated by the two separate clipboards in X/Gnome. I'm constantly doing things like control-C to copy, and then middle-click to paste, and getting the wrong data. Or select ...
31
votes
8answers
7k views

Is flash drive wear a significant issue?

My netbook has a flash drive instead of a hard disk drive, and I'm using Ubuntu Netbook Remix with ext3 as the file system. I've read some articles concerning flash drive wear, and the main concerns ...
31
votes
3answers
13k views

Bad font anti-aliasing in Ubuntu

I'm switching from Fedora 8 to Ubuntu 9.04, and I can't seem to get it to get a good font anti-aliasing to work. It seems that Ubuntu's fontconfig tries to keep characters in integral pixel widths. ...
31
votes
2answers
4k views

Is it possible to compile a Darwin Distro from source, like you can a build a Linux Distro?

I have read through and undertaken Linux From Scratch (and BLFS) and I was wondering, can I follow this guide to create a Darwin Distro by substituting the xnu kernel? Would the process be vastly ...
30
votes
10answers
3k views

Prevent user typing accidental space between rm and wildcard

Intention: rm -rf string* Problem: rm -rf string * The first case is a legitimate and common use of rm, a small typo can cause a lot of problems in the second case. Is there a simple way to ...
30
votes
5answers
2k views

Deleting millions of files

I had a dir fill up with millions of gif images. Too many for rm command. I have been trying the find command like this: find . -name "*.gif" -print0 | xargs -0 rm Problem is, it bogs down my ...
30
votes
8answers
11k views

Swap partition size on a 64 GB RAM computer for memory-intensive work

I have 64 GB RAM and 240 GB SSD on my computer, which I'm going to use for memory-intensive calculations (machine learning, data mining, etc.). Most of the advice I found on the Internet are ...
30
votes
3answers
41k views

How to get list of dependencies of non-installed RPM package?

apt-cache show <package> shows also it's dependencies. yum info <package> does not show dependencies, but it obviously know them. How to ask yum for dependencies of specified package?
30
votes
4answers
14k views

How to: Unlimited Bash/shell history?

Is there a way to define an unlimited history in Bash ?