Use this tag for questions about file management and operations on files.

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24
votes
4answers
11k views

How to properly and easy configure `xdg-open` without any enviroment?

I'm using OpenBox window manager without any desktop enviroment. xdg-open behaves strangely. It opens everything with firefox. $ xdg-settings --list Known properties: default-web-browser ...
13
votes
5answers
23k views

Test if there are files matching a pattern in bash

I am trying to write an if statement in bash to test whether there are any files matching a certain pattern. If there is a text file in a directory it should run a given script. My code currently if ...
19
votes
4answers
2k views

Is there an “open with” command for the command line?

Does the command line have a way to get a recommended list of programs used to open a particular file, based on the file type? For example, a .pdf file would have an open with... recommendation using ...
38
votes
6answers
116k views

How to get over “device or resource busy”?

I tried to rm -rf a folder, and got "device or resource busy". In Windows, I would have used LockHunter to resolve this. What's the linux equivalent? (Please give as answer a simple "unlock this" ...
15
votes
2answers
12k views

What does the 'd' mean in ls -al results and what is that slot called? [duplicate]

In Linux, what does the d mean in the first position of drwxr-xr-x? And what are all of the possible letters that could be there, and what do they mean? I'm trying to learn more about the Linux file ...
14
votes
5answers
12k views

How to copy directories with preserving hardlinks?

How to move directories that have files in common from one to another partition ? Let's assume we have partition mounted on /mnt/X with directories sharing files with hardlinks. How to move such ...
50
votes
3answers
157k views

Get file created/creation time? [duplicate]

Possible Duplicate: How do I do a ls and then sort the results by date created? Is there a command in Linux which displays when the file was created ? I see that ls -l gives the last ...
20
votes
8answers
46k views

List only regular files (but not directories) in current directory

I can use ls -ld */ to list all the directory entries in the current directory. Is there a similarly easy way to just list all the regular files in the current directory? I know I can use find find . ...
14
votes
2answers
19k views

What are character special and block special files in a unix system?

How are character special files and block special files different from regular files in a Inix-like system? Why are they called “character special” and “block special” respectively?
13
votes
2answers
473 views

How can I be sure that a directory or file is actually deleted?

I know that most files, when deleted, aren't actually removed from the disk, and can be recovered later. How can I ensure that a directory I had deleted will actually be removed from the disk? Are ...
14
votes
3answers
23k views

how to output text to both screen and file inside a shell script?

Currently I have a shell script which logs messages to a log file like this: log_file="/some/dir/log_file.log" echo "some text" >> $log_file do_some_command echo "more text" >> $log_file ...
11
votes
3answers
11k views

Quickly find which file(s) belongs to a specific inode number

I know of this command: find /path/to/mountpoint -inum <inode number> but it is a very slow search, I feel like there has to be a faster way to do this. Does anybody know a faster method?
10
votes
3answers
35k views

undelete a just deleted file on ext4 with extundelete

Is there a simple option on extundelete how I can try to undelete a file called /var/tmp/test.iso that I just deleded? (it is not so important that I would start to remount the drive read-only or ...
11
votes
3answers
6k views

Can files be created with permissions set on the command line?

When creating directories, mkdir -m <mode> <dir> provides for creating one or more directories with the given mode/permissions set (atomically). Is there an equivalent for creating files, ...
14
votes
3answers
4k views

Determining if a file is a hard link or symbolic link?

I'm creating a shell script that would take a a filename/path to a file and determines if the file is a symbolic link or a hard link. The only thing is, I don't know how to see if they are a hard ...
13
votes
2answers
878 views

Is that possible to integrate zip and tar.gz files as directory into the file system

I wonder if there is a way to integrate (it's a bit different from mounting, I think) compressed files as directories into the file system? E.g., one could download a compressed-file.tar.gz to his ...
9
votes
4answers
24k views

How do I append text to the beginning and end of multiple text files in Bash?

I have a directory full of text files. My goal is to append text to the beginning and end of all of them. The text that goes at the beginning and end is the same for each file. Based on code I got ...
9
votes
4answers
5k 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 ...
4
votes
4answers
2k views

Clone directory tree structure and copy files to the corresponding directories modified after a specific date

I have a folder with more than 30 sub directories and I want to get the list of the files which was modified after a specified date(say sep 8 which is the real case) and to be copied with the same ...
10
votes
1answer
10k views

Group within group file permissions

I tried finding this on here, but couldn't so sorry if it's a duplicate. Say I have 2 groups and a user: group1, group2, user1 with the following structure: group1 is a member of group 2, user1 is a ...
9
votes
5answers
6k views

Keep log file size fixed without logrotate

Is there any way to keep file size of log file fixed without rotating it by a new empty file and deleting (or archiving) the old file. For example, if I set log file maximum size to 1MB, after the ...
8
votes
2answers
5k views

Group member cannot write even with write permission

The logged in user is a member of a group that has a write permission on a folder. But when this user is trying to write something, "permission is denied". The log below summarizes the question: ...
7
votes
2answers
6k views

How to circumvent “Too many open files” in debian

If I want to see all relevant log files of my apache2 server at once, I use tail -f /var/kunden/logs/*log /var/kunden/logs/*log /var/log/apache2/*log |grep -v robots|grep -v favicon But since those ...
6
votes
4answers
1k views

Delete all files in a directory whose name do not match a line in a file list

I have a directory with 1000+ files. In a text file, I have about 50 filenames, one per line. I'd like to delete all the files in the directory whose filenames don't correspond with an entry on the ...
5
votes
3answers
14k views

granting write permissions to a group to a folder

How can I grant write permission to 1 group ? I have 2 users (alex and ben). alex is member of group alex and of group consult. ben is member of group ben and of group consult. I want to grant read ...
5
votes
8answers
3k views

Run a command on all subfolders

If you have a series of subfolders (like from a to z) and want to run a command on each one of them (like rm *.pdf or ls *.pdf), how do you do that? The "manual" approach would be cd a, rm *.pdf, or ...
4
votes
2answers
13k views

List of Recently Modified Files

How can I Get a list of all files modified , say 3 months ago. I checked this question but I was not able to apply it to my scenario. I am trying this now , it seems to be working , but I know there ...
3
votes
2answers
2k views

Concatenate specific files into one single file

In a folder containing X files, I need to concatenate Y files (where X > Y) together into a single text file. I have the filenames (of Y files) that I need to concatenate. Can anyone please help me ...
9
votes
4answers
5k views

How do you compare two folders and copy the difference to a third folder?

You've got three folders: folder current, which contains your current files folder old, which contains an older version of the same files folder difference, which is just an empty folder How do ...
9
votes
2answers
5k 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 ...
8
votes
1answer
282 views

What three files are always opened by a process?

Someone mentioned that there are three different files that a process always opens. What does this mean? What files are they?
4
votes
2answers
340 views

Why does 'find -delete ' delete all files in a directory recursively

So the following behaviour of unix find just cost me dearly: > touch foo > touch bar > ls bar foo > find . -name '*oo' -delete > ls bar > touch baz > ls bar baz > find . ...
4
votes
3answers
1k views

Create a virtual file that is actually a command

Is there any way to create a virtual file, such that reading from the file actually reads from the stdout of a command; writing to the file is acually writing to the stdin of a command? So far I have ...
4
votes
2answers
808 views

List files created on Sundays

How do I list/find all the files created on Sundays or Mondays? How do I use the date parameter to display them? Something like : ls -f date + %a or find -type f | date +%A or find -type f ...
3
votes
3answers
88 views

Can a file be edited with the 'write' permission on it but not on its parent directory?

Suppose the owner/user doesn't have the write permission on a directory but he has it on a file under it. Can the file here be edited or not? If yes, is there any situation where the file cannot be ...
3
votes
3answers
1k views

How is it possible to do a live update while a program is running?

I wonder how killer applications such as Thunderbird or Firefox can be updated via the system's package manager while they are still running. What happens with the old code while they are being ...
3
votes
1answer
325 views

How does the Linux file structure work?

I see the different folders bin, dev, mnt, proc, srv, sys, etc. What are the properties of all these different folders? What are there purposes? Are there files in some of them that I should not ...
2
votes
3answers
580 views

What command do I use to see the start and end block of a file in the file system?

Is there any command that will output the beginning and ending blocks of any file?
1
vote
4answers
572 views

How to delete the files in one folder which are more than 60 days old in UNIX?

I know how to delete the files which are more than 60 days old by modification time, but I want to delete files based on a timestamp in the file name. For example, I have the below files for each day ...
8
votes
3answers
4k views

How to remove only the content of directories?

I'm in a folder: /var/myfolder. Inside there are some other folders like: /var/myfolder/A/ /var/myfolder/B/ `/var/myfolder/C/ etc. Inside each there are some files with random names. How do I ...
8
votes
4answers
9k views

Number of files containing a given string

How can I count the number of files (in a directory) containing a given string as input in bash/sh?
7
votes
3answers
362 views

Find the top 50 directories containing the most files/directories in their first level?

How can I use find to generate a list of directories which contain the most numbers of files. I'd like the list to be from highest to lowest. I'd only like the listing to go 1 level deep, and I'd ...
6
votes
5answers
2k views

Find images by size: find / file / awk

I've been trying to find png image files a certain height (over 500px). I know that file will return image dimensions. Example: $ file TestImg1a.png TestImg1a.png: PNG image data, 764 x 200, ...
6
votes
3answers
1k views

Best way to swap filenames

I need to swap filenames of two files (file and file_1). I'm using the following code for it. mv file .phfile mv file_1 file mv .phfile file This works but is very buggy, It sometimes even results ...
5
votes
2answers
765 views

How to delete a directory automatically when an executable is killed

Quite often, we run an executable that needs to write / read some temporary files. We usually create a temporary directory, run the executable there, and delete the directory when the script is done. ...
5
votes
2answers
109 views

Making a process read a different file for the same filename

I have an application that reads a file. Let's call it processname and the file ~/.configuration. When processname runs it always reads ~/.configuration and can't be configured differently. There are ...
4
votes
2answers
3k views

Local Account Creation Date

For compliance purposes there is the need to fetch information regarding local (user and non-user) accounts creation date on UNIX machines. Is there any way (even if it's not the most reliable or ...
4
votes
1answer
237 views

When was file created [duplicate]

How can i see when a file was created. I have looked at man page ls -lc is for last modification of file status ls -lu for access time ls -l not exactly indicated which time, last changed? I ...
3
votes
2answers
132 views

Back up and restore file permissions

Is there a way to back up and restore file ownership and permissions (the things that can be changed with chown and chmod)? You can do this in Windows using icacls. What about access control lists?
3
votes
6answers
423 views

redirect output to specific line number

I want to grep certain lines by keyword and redirect the output to specific line number of an existing file. Command grep "key" temp_file >> desired.txt What I need is that I can append the ...