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Questions tagged [directory]

A file system structure in which to store computer files.

364
votes
7answers
251k 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 ...
249
votes
4answers
395k 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 ...
233
votes
12answers
355k views

How do I loop through only directories in bash?

I have a folder with some directories and some files (some are hidden, beginning with dot). for d in *; do echo $d done will loop through all files, but I want to loop only through directories. How ...
176
votes
10answers
323k views

How can I calculate the size of a directory?

How to know the size of a directory? Including subdirectories and files.
167
votes
17answers
211k 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 ...
157
votes
5answers
521k views

How can I get the current working directory? [duplicate]

I want to have a script that takes the current working directory to a variable. The section that needs the directory is like this dir = pwd. It just prints pwd how do I get the current working ...
154
votes
4answers
92k 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 ...
153
votes
7answers
168k 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 ...
142
votes
6answers
75k 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 ...
137
votes
11answers
172k 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?
130
votes
9answers
189k views

Find the total size of certain files within a directory branch

Assume there's an image storage directory, say, ./photos/john_doe, within which there are multiple subdirectories, where many certain files reside (say, *.jpg). How can I calculate a summary size of ...
128
votes
8answers
245k views

How to recursively find the amount stored in directory?

I know you are able to see the byte size of a file when you do a long listing with ll or ls -l. But I want to know how much storage is in a directory including the files within that directory and the ...
128
votes
8answers
52k 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 ...
116
votes
10answers
225k 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 ...
114
votes
7answers
45k 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 ....
110
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 ...
109
votes
4answers
452k 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 ...
105
votes
12answers
95k views

How to XZ a directory with TAR using maximum compression?

So I need to compress a directory with max compression. How can I do it with xz? I mean I will need tar too because I can't compress a directory with only xz. Is there a oneliner to produce e.g. foo....
95
votes
4answers
124k views

How to copy-merge two directories? [duplicate]

I have two directories images and images2 with this structure in Linux: /images/ad /images/fe /images/foo ... and other 4000 folders and the other is like: /images2/ad /images2/fe /...
82
votes
7answers
64k 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 ...
81
votes
5answers
67k 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 ...
79
votes
3answers
174k 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 ...
78
votes
2answers
4k 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 ...
78
votes
8answers
374k 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 ...
77
votes
5answers
34k 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 ...
76
votes
14answers
445k views

How to remove all the files in a directory?

I am trying to remove all files and subdirectories in a directory. I used rm -r to remove all files, but I want to remove all files and subdirectories, excluding the top directory itself. For example,...
70
votes
5answers
7k views

Pronunciation for /usr directory

How do you pronunce /usr? I found in the net that someone reads it "user"... but, for what I know, this directory is not related to the user. The meaning of the acronym is "Unix specific (or system) ...
66
votes
6answers
34k 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 ...
62
votes
8answers
56k 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?
61
votes
4answers
20k 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?
58
votes
7answers
81k views

rsync compare directories?

Is it possible to compare two directories with rsync and only print the differences? There's a dry-run option, but when I increase verbosity to a certain level, every file compared is shown. ls -alR ...
56
votes
5answers
3k views

cd by just typing the directory's name?

I either had this somewhere 20 years ago or I dreamed about it. Basically: If if type blobblob I get blobblob: command not found Fair enough. I would like it so that when my shell gets those ...
55
votes
4answers
33k 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 ...
54
votes
3answers
34k views

Difference between “cd -” and “cd ~-”

The Bash command cd - prints the previously used directory and changes to it. On the other hand, the Bash command cd ~- directly changes to the previously used directory, without echoing ...
54
votes
3answers
67k 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 ...
52
votes
13answers
38k 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 ...
51
votes
5answers
102k views

How do I remove all sub-directories from within a directory?

This question is kind of a phase II to the first question I posted at here I have a directory that contains a bunch of sub-directories, .zip files, and other random files not contained within a sub-...
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 ...
50
votes
3answers
32k views

How to make tree output only directories?

150 directories I can handle but 900 files is too many for a review. I've no manual entry for tree so maybe I can ask you if you know how to output only directories since files get too detailed? . ├──...
46
votes
4answers
93k 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 ...
44
votes
6answers
11k views

cd .. on root folder

Why cd .., typed at root folder, does not warn or fails with an error? I would expect: /$ cd .. -bash: cd: ..: No such file or directory Instead, I'm left at /. Of course, this is since .. does ...
44
votes
3answers
20k views

Finding the correct tmp dir on multiple platforms

I have a script that needs to create temporary files for its work, and clean up after itself. My question is about finding the right base directory for the temporary files. The script needs to work ...
43
votes
6answers
144k views

How can I list subdirectories recursively?

The obvious ls -dR does not work. I am currently using find /path/ -type d -ls but the output is not what I need (plain listing of sub-folders) Is there a way out?
41
votes
8answers
164k views

Using sftp to Transfer a Directory?

When I try to use sftp to transfer a directory containing files, I get an error message: skipping non-regular file directory_name The directory contains a couple of files and two subdirectories. ...
40
votes
4answers
59k 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 ...
40
votes
9answers
43k 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 ...
39
votes
2answers
7k views

Why can't I remove the '.' directory?

I tried removing the '.' directory. I thought I could just delete my working directory without having to go into a parent directory. The point of my question is to look for some insight into how the ...
37
votes
1answer
46k 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-...
35
votes
6answers
6k views

Is ~/Mary a relative path? [duplicate]

Let's suppose Mary is a directory. Is the following path ~/Mary relative?
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 ...