Questions tagged [directory]

A file system structure in which to store computer files.

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370
votes
8answers
257k views

Execute vs Read bit. How do directory permissions in Linux work?

In my CMS, I noticed that directories need the executable bit (+x) set for the user to open them. Why is the execute permission required to read a directory, and how do directory permissions in Linux ...
111
votes
6answers
20k views

How does Linux handle multiple consecutive path separators (/home////username///file)?

I'm working on a python script that passes file locations to an scp subprocess. That's all fine, but I'm in a situation where I may end up concatenating a path with a filename such that there's a ...
84
votes
7answers
66k views

The result of ls * , ls ** and ls ***

I know using the command ls will list all the directories. But what does the ls * command do ? I used it and it just lists the directories. Is the star in front of ls means how deep it can list the ...
65
votes
4answers
21k views

What does size of a directory mean in output of 'ls -l' command?

What does size of a directory mean in output of ls -l command?
251
votes
4answers
405k views

How to set default file permissions for all folders/files in a directory?

I want to set a folder such that anything created within it (directories, files) inherit default permissions and group. Lets call the group "media". And also, the folders/files created within the ...
25
votes
4answers
20k views

How to run a command when a directory's contents are updated?

There is a directory A whose contents are changed frequently by other people. I have made a personal directory B where I keep all the files that have ever been in A. Currently, I just occasionally ...
146
votes
6answers
77k views

How to remove all empty directories in a subtree?

How can I remove all empty directories in a subtree? I used something like find . -type d -exec rmdir {} 2>/dev/null \; but I needs to be run multiple times in order to remove directories ...
156
votes
4answers
94k views

Do the parent directory's permissions matter when accessing a subdirectory?

If I have a root folder with some restrictive permission, let's say 600, and if the child folders/files have 777 permission will everybody be able to read/write/execute the child file even though the ...
123
votes
10answers
234k views

Script to monitor folder for new files?

How to detect new files in a folder with a bash script? I would like to process the files as soon as they are created in the folder. Is this possible to do so or do I have to schedule a script with ...
84
votes
3answers
181k views

Getting new files to inherit group permissions on Linux

I am having a problem with permissions on a Linux server. I am used to BSD. When a directory is owned by a group the user who owns it isn't in such as www-data, files created in it will be owned by ...
24
votes
8answers
6k views

Any way to sync directory structure when the files are already on both sides?

I have two drives with the same files, but the directory structure is totally different. Is there any way to 'move' all the files on the destination side so that they match the structure of the ...
129
votes
8answers
53k views

Why are hard links to directories not allowed in UNIX/Linux?

I read in text books that Unix/Linux doesn't allow hard links to directories but does allow soft links. Is it because, when we have cycles and if we create hard links, and after some time we delete ...
58
votes
4answers
34k views

When should I use a trailing slash on a directory? [duplicate]

Possible Duplicate: How linux handles multiple path separators (/home////username///file) Most commands I use in linux behave exactly the same whether I include the trailing slash / character on ...
35
votes
2answers
30k views

Why does a new directory have a hard link count of 2 before anything is added to it?

Say I just create directory newDirectory and then I do ls -ld command. I see that the number of hard links is 2. What exactly makes the hard link 2 from the start? Also is the number of subdirectories ...
10
votes
10answers
17k views

What's the best way to count the number of files in a directory?

If parsing the output of ls is dangerous because it can break on some funky characters (spaces, \n, ... ), what's the best way to know the number of files in a directory? I usualy rely on find to ...
116
votes
7answers
46k views

What does the .d stand for in directory names?

I know many directories with .d in their name: init.d yum.repos.d conf.d Does it mean directory? If yes, from what does this disambiguate? UPDATE: I've had many interesting answers about what the ....
32
votes
2answers
14k views

Where do the files go if you mount a drive to a folder that already contains files?

I just accidentally mounted a new drive to a folder that already contained files. I don't care about them and have them somewhere else, but that folder appears empty now. I'm curious what happened ...
29
votes
1answer
1k views

When did directories stop being readable as files?

I have the 1st edition of The Unix Programming Environment book. In chapter 2, the authors state that directories are readable as files, and mention some facts about the format of these files. They ...
145
votes
11answers
180k views

Merging folders with mv?

If I use mv to move a folder called "folder" to a directory that already contains "folder" will they merge or will it be replaced?
38
votes
1answer
47k views

command to zip multiple directories into individual zip files

I have a single directory that contains dozens of directories inside of it. I'm new to command line and I'm struggling to come up with a command that will zip each sub-directory into a unique sub-...
80
votes
5answers
35k views

How can I create a /dev/null-like “blackhole” directory?

I would like to create a "/dev/null" directory (or a "blackhole" directory) such that any files written to it are not really written, but just disappear. I have an application that writes out large ...
15
votes
1answer
23k views

In Linux, is “write” permission equivalent to “execute” for directories?

The execute permission makes sense for files (which include scripts etc.), but when it comes to directories, the write (w) permission works the same way as execute (x), right? Which means, if we are ...
10
votes
5answers
1k views

List all directories that do NOT have a file with a given file name inside

How would I go into listing all directories that do not have a file with a given file name inside? e.g. given this tree / /a README file001 file002 /b README file001 /c ...
40
votes
4answers
61k views

Is there any way to prevent deletion of certain files from user owned directory?

Let's say user has Directory1 and it contains File1 File2 CantBeDeletedFile How to make so the user would never be allowed to delete the CantBeDeletedFile? If I change the ownership of Directory1 and ...
51
votes
2answers
3k views

Why is '.' a hard link in Unix?

I've seen many explanations for why the link count for an empty directory in Unix based OSes is 2 instead of 1. They all say that it's because of the '.' directory, which every directory has pointing ...
48
votes
4answers
98k views

Determine what device a directory is located on

If I do # cd / # ln -s /home test # cd test # mount --bind $PWD /mnt the entry in /proc/mounts is /dev/sda2 /mnt ext4 rw,noatime,data=ordered 0 0 which is the device that is mounted to /home and ...
30
votes
3answers
36k views

How can I move files by type recursively from a directory and its sub-directories to another directory?

What would be a good way to move a file type from a directory and all of its sub-directories? Like "move all *.ogg in /thisdir recursively to /somedir". I tried a couple of things; my best effort was ...
15
votes
7answers
26k views

How do I change folder timestamps recursively to the newest file?

I was wondering if anyone knows how to change the timestamps of folders recursively based on the latest timestamp found of the files in that folder. So for example: jon@UbuntuPanther:/media/media/...
10
votes
1answer
24k views

How can I make ls show information about the directory specified only, not info about its sub-files or folder contents?

Say I have folder "foo" residing, the home directory. I want to get some info of it, owner, group, permissions, etc... I then do this to try to get the information: cd ~ ls -l foo Of course it now ...
15
votes
1answer
4k views

How to find all the links to a directory

When I stat a directory I get a listing that tell me there are 5 links to the directory. stat dir My question is how do I get information (names and locations) to all these 5 links?
167
votes
7answers
174k views

What is the 'working directory' when cron executes a job?

I have a script that works when I run it from the command line, but when I schedule it with cron I get errors that it cannot find files or commands. My question is twofold: When I schedule a cron ...
110
votes
4answers
455k views

Create a symbolic link relative to the current directory

I'm trying to create a symbolic link in my home directory that points to a directory on my external HDD. It works fine when I specify it like this: cd ~ ln -s /run/media/name/exhdd/Data/ Data ...
78
votes
8answers
388k views

“Input/output error” when accessing a directory

I want to list and remove the content of a directory on a removable hard drive. But I have experienced "Input/output error": $ rm pic -R rm: cannot remove `pic/60.jpg': Input/output error rm: cannot ...
78
votes
2answers
5k views

Why does '/' have an '..' entry?

This has always puzzled me. Why does the root directory contain a reference to a parent directory? bob@bob:/$ ls -a . build home lib32 mnt .rpmdb sys vmlinuz .. cdrom ...
54
votes
14answers
39k views

What's the most resource efficient way to count how many files are in a directory?

CentOS 5.9 I came across an issue the other day where a directory had a lot of files. To count it, I ran ls -l /foo/foo2/ | wc -l Turns out that there were over 1 million files in a single ...
57
votes
3answers
69k views

Why unix mv program doesn't need -R (recursive) option for directories but cp does need it?

I always get messed up when need to use cp or mv: "do I need -R option when working with dir?" In GNU coreutils cp does need -R and mv doesn't. I just can not find any reason why cp needs -R option ...
23
votes
6answers
8k views

mkdir -p for files

mkdir -p will create a directory; it will also make parent directories as needed. Does a similar command exist for files, that will create a file and parent directories as needed?
21
votes
5answers
20k views

How can I copy a file and create the target directories at the same time?

I want to cp aaa/deep/sea/blob.psd to bbb/deep/sea/blob.psd How do I do the copy if the deep and sea directories don't exist under bbb so that the copy both creates the directories that are needed ...
40
votes
9answers
44k views

How to delete this undeletable directory?

I untarred a corrupt tar file, and managed to end up with some directory that I can not delete, If I try to delete it, it seems like it can not be found, but ls shows it's present, both with bash and ...
17
votes
5answers
10k views

How to set an alias on a per-directory basis?

Suppose you have an alias go, but want it to do different things in different directories? In one directory it should run cmd1, but in another directory it should run cmd2 By the way, I have an ...
18
votes
3answers
26k views

What are ./ and ../ directories?

Simple question, but I'm not sure where to look and google doesn't respond to periods and slashes. I'm just trying to count the # of files & directories in the current directory (not including ...
15
votes
1answer
7k views

Why is this empty directory 3.5MB?

I've just read this question: What does size of a directory mean in output of 'ls -l' command? ...which doesn't quite answer my question. Basically, I'm moving files onto a NAS. The folders I'...
10
votes
3answers
4k views

Delete all files except in a certain subdirectory with find

I want to recursively delete all files not accessed in a while in folder a, except all files in the subfolder b. find a \( -name b -prune \) -o -type f -delete However, I get an error message: ...
8
votes
3answers
808 views

“mkdir foo; svn mv * foo”

I often want to do some variant of this idiom: $ mkdir 2010 $ svn mv * 2010 Of course, I get an error because the glob matches 2010 as well: svn: Cannot copy path '2010' into its own child '2010/...
2
votes
1answer
411 views

What happens when the current directory is deleted?

In the first terminal A, I create a directory, enter the directory, and create a file: $ mkdir test $ cd test $ touch file1.txt $ ls file1.txt Then in another terminal B, I delete the directory: $ ...
169
votes
17answers
218k views

How do I get the MD5 sum of a directory's contents as one sum?

The md5sum program does not provide checksums for directories. I want to get a single MD5 checksum for the entire contents of a directory, including files in sub-directories. That is, one combined ...
67
votes
6answers
35k views

Flattening a nested directory

This is probably very simple, but I can't figure it out. I have a directory structure like this (dir2 is inside dir1): /dir1 /dir2 | --- file1 | --- file2 What is ...
82
votes
5answers
69k views

Difference between /bin and /usr/bin

I read this up on this website and it doesn't make sense. http://rcsg-gsir.imsb-dsgi.nrc-cnrc.gc.ca/documents/basic/node32.html When UNIX was first written, /bin and /usr/bin physically resided ...
62
votes
8answers
59k views

Converting relative path to absolute path without symbolic link

Is there a Unix command to get the absolute (and canonicalized) path from a relative path which may contain symbolic links?
18
votes
4answers
15k views

How are directories implemented in Unix filesystems?

My question is how directories are implemented? I can believe a data structure like a variable e.g. table, array or similar. Since UNIX is Open Source I can look in the source what the program does ...