A file system structure in which to store computer files.

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Lowercasing all directories under a directory

I want to lowercase every directories' name under a directory. With which commands can I do that?
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5answers
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Creating numerous directories using mkdir

I would like to create many directories using mkdir. Each directory name will consist of a prefix (a string) and an index (an integer). Suppose that I would like the prefix to be "s" and the indices ...
9
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7answers
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How do I create a directory in all subdirectories?

Suppose I have a directory structure like this: $ [~/practice] ls a/ b/ c/ d/ Now I want to create a directory tmp1 in all sub directories of practice and I do this: $ [~/practice] mkdir */tmp1 ...
9
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3answers
2k views

what is wild card to select all directories in a directory

i want to set sticky bit for all directories in a directory excluding files. is there any wild card to do this? #sudo chmod g+s /var/www/<WILD_CARD_FOR_ALL_DIRECTORIES>
9
votes
4answers
3k views

pv for directory copy

I need to copy a very large directory (talking in terabytes here) and want to monitor the progress. I found that pv is a nice utility, but how can I use it for copying directories recursively? (pv ...
9
votes
2answers
365 views

How to spoof/mock a directory used by a binary application as another directory?

Suppose there's a binary application that always writes its data to /tmp. How could I spoof/mock /tmp for the sake of this binary as some other directory (e.g. home/tmp)? Let's assume I have no ...
9
votes
1answer
3k views

Why can't I have a folder and a file with the same name?

I've never had this problem before, but for some reason, I can't rename my folder to packages/. This is the structure: root - packages_old/ - packages When I try to rename the folder with ...
9
votes
1answer
663 views

What is the difference between 'ls' and 'ls -l' when I don't have execute permission on that directory?

I created a directory called folder and took away execute permission. $ mkdir folder $ touch folder/innerFile $ mkdir folder/innerFolder $ chmod -x folder Now if I do $ ls folder it outputs a ...
9
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3answers
756 views

Why are some files and folders hidden?

I can understand the rationale of hiding files and folders in the /home/user directory to prevent users from messing around with things. However, I do not see how the same rationale can be applied to ...
9
votes
4answers
1k views

Recursively iterate through files in a directory

Recursively iterating through files in a directory can easily be done by: find . -type f -exec bar {} \; However, the above does not work for more complex things, where a lot of conditional ...
9
votes
2answers
2k views

Stay at same working directory when changing to sudo

When working on the command line, I often change to sudo using sudo -i. However, my working directory changes automatically to /root. I never want to go there; I want to stay where I was! How can I ...
8
votes
5answers
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Bash CD up until in certain folder

I do a lot of work in Magento, and so do a lot of the people I work with, and it gets annoying to have to type: cd ../../../../../../ To only find you're still a few directories from your root ...
8
votes
4answers
4k 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 ...
8
votes
6answers
849 views

Best way run a command on each file in a directory tree

There appear be a number of ways to do this including loops in shell script, find and xargs. Which of these is best, and which is most portable?
8
votes
4answers
28k 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?
8
votes
3answers
2k 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 ...
8
votes
4answers
3k views

How does one atomically change a symlink to a directory in busybox?

I am trying to (as close as possibly) atomically change a symlink. I've tried: ln -sf other_dir existing_symlink That just put the new symlink in the directory that existing_symlink pointed to. ln ...
8
votes
3answers
462 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 ...
8
votes
6answers
2k views

Remove empty directory trees (removing as many directories as possible but no files)

Suppose I have a dir tree like this: ROOTDIR └--SUBDIR1 └----SUBDIR2 └----SUBDIR3 I am looking for a command such that when I input: $ [unknown command] ROOTDIR The whole ...
8
votes
3answers
1k views

How can I cd to the previous/next sibling directory?

I often have a project directory layout like this project `-- component-a | `-- files... `-- component-b | `-- files... `-- component-c `-- files... I'll usually be working in one of the ...
8
votes
2answers
845 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
1answer
1k views

Can rm recursively remove empty directories?

In an old version of Unix, the rm command would delete directories if they were empty. From the Research Unix Eighth Edition man page for rm: "If an entry is a directory it is removed only if empty." ...
8
votes
2answers
363 views

Boot into a chroot?

I have Linux (Debian Jessie) installed on a hard drive. Drive - sda1, ext4fs, and sda2 - swap I have a /chroot folder. There is installed another system, in /chroot folder. Question: How to tell ...
8
votes
4answers
6k views

How can I force unzip / zip not to create a subdirectory when I extract it?

Depending on how a zip file is created, sometimes it will extract all of the files directly, and sometimes it will extract the files into a subdirectory. If the latter is true, how can I force the ...
7
votes
6answers
1k views

Is it possible to remove folder prefix from a `ls` command

I am in a bash script and I want to get the list of all files (let say all jar files). I execute the command ls -1 lib/*.jar and I get the output: lib/mylib_1.jar lib/mylib_2.jar ... Is there any ...
7
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6answers
7k views

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

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 ...
7
votes
7answers
6k views

How to check if $PWD is a subdirectory of a given path

E.g. check if $PWD is a subdirectory of /home. In other words I'm searching for a bash string operation to check if one string starts with another.
7
votes
3answers
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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 ...
7
votes
5answers
11k 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 ...
7
votes
2answers
1k views

Is there a correct way to list the subdirectories of the current directory?

I can find the subdirectories of a directory by ls -d -- */ or ls -l | grep "^d" but both of these seem indirect, and I would imagine that there would be a standard way to find just the ...
7
votes
3answers
7k 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: ...
7
votes
5answers
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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. ...
7
votes
4answers
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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 ...
7
votes
4answers
2k views

Find files with same name but different content?

I want to generate a list of files that have: Same name Different content in a directory (including all children directories and content). How to do? Bash, perl, anything is fine. So, two ...
7
votes
1answer
430 views

What is the significance of the dot in bash commands and how is it different from an asterisk?

I'm trying to understand the significance of the dot in bash and how it differs from an asterisk. Can someone please elaborate? For example, what's the difference between cp -ar /foo/. /foo2/ and cp ...
7
votes
1answer
161 views

Why are rmdir and unlink two separate system calls?

Here's something that kept me wondering for a while: [15:40:50][/tmp]$ mkdir a [15:40:52][/tmp]$ strace rmdir a execve("/usr/bin/rmdir", ["rmdir", "a"], [/* 78 vars */]) = 0 brk(0) ...
7
votes
1answer
906 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 ...
6
votes
1answer
361 views

Expand ~, . and `..`

Since ~, . and .. are special directories, why are they handled differently in the following example? $ echo ~ /home/tim $ echo .. .. $ echo . . ~ is expanded into the dir, but the other two are ...
6
votes
5answers
928 views

Making a directory protected from 'rm -rf'

I just lost some data in folder A which was inside folder B after doing rm -rf B. Before I could realize what have I done, it was all over. Now a lesson is learnt, I wish to make some of my folder ...
6
votes
3answers
2k views

vim: How to switch to the directory listing from file view?

I have opened a dir vim some/dir. I can navigate within the tree, yet once I opened a file I wonder, how do I close the file view in order to go back to the directory listing to navigate to another ...
6
votes
1answer
2k views

how to view a directory's permission

What is the command with which you can directly view the permission bits of a directory?
6
votes
3answers
363 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 ...
6
votes
4answers
780 views

set read and write permissions to folder and all its parent directories

I need to set read and write permissions for root user to directory subfolderN and all its parent folders till root. I can do it by hands: $ sudo chmod +rx /root/subfolder1/subfolder2/subfolderN $ ...
6
votes
2answers
239 views

How does one create a directory that can't be seen and can only be accessed via its absolute path name?

I'm working on an assignment on adding time support to a standard UNIX system. Part of it, however, involves securing the location of backup files (which we've set to be at the system root by default) ...
6
votes
2answers
6k 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 ...
6
votes
2answers
342 views

Using NIS without NFS

I'm configuring several computers in a lab to operate with the same login credentials shared between the computers, but without sharing the home directories. I'm considering using NIS for sharing the ...
6
votes
3answers
1k views

Read a directory to see the file to inode mapping

I'm just learning about filesystems and it is said that a directory is just an ordinary file which keeps a list of file-inode pairs. If I try to open the directory Downloads with any of the following ...
6
votes
1answer
786 views

Why could the size of the “dot” file “.” exceed 4096?

Today I found an "empty" directory with a size of 4MB. It had no visible contents, so I tried ls -lah. This showed me some hidden files (not very large). Searching for the reason why the directory ...
6
votes
4answers
2k views

Recursively rename subdirectories that match a regex

I have a media server with a folder called Series. (/media/Expansion2/Series/) In it, I have (surprise!) TV series. These are just the show names, e.g., /media/Expansion2/Series/The Big Bang Theory/ ...
6
votes
1answer
138 views

cd and ls behave differently when inside a softlink to a dir

When we cd into a dir via its softlink, i observe: ls .. will show the content of the parent dir of the linked dir, while cd .. will go under the parent dir of the softlink. Why are they different? ...