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

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13
votes
2answers
715 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
16k 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
5answers
3k views

How to create a file even root user can't delete it

How to create a file even root user can't delete it ?
7
votes
6answers
8k 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 ...
6
votes
3answers
17k 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 ...
4
votes
5answers
1k 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 ...
9
votes
5answers
5k 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
4k 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, ...
7
votes
2answers
4k 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: ...
6
votes
4answers
984 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 ...
6
votes
1answer
5k 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 ...
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
3answers
5k 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 ...
4
votes
2answers
10k 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
1k 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 ...
13
votes
1answer
177 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 ...
9
votes
1answer
8k 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
1answer
4k 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
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 ...
6
votes
3answers
470 views

How can I make a special file that executes code when read from

Most files on a Linux system are normal files, i.e. they are saved on disk and reading from them just reads from a specified chunk of memory on the disk. How can I make something that behaves like a ...
4
votes
2answers
199 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
2answers
632 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
1answer
313 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
788 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 ...
2
votes
3answers
400 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
360 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
3k 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 ...
7
votes
4answers
7k 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?
6
votes
3answers
268 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
1k 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
868 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 ...
4
votes
2answers
2k 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
204 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 ...
4
votes
2answers
442 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. ...
4
votes
4answers
15k views

Linux file access monitoring

Is there any way in unix to find out who accessed certain file in last 1 week? It may be user or some script ftp it to some other place. Can I get a list of user name who accessed certain file? How ...
3
votes
2answers
38 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
144 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 ...
3
votes
4answers
117 views

Determining the number of files and subdirectories in Linux

When displaying directories in linux using ls -ld, I get something like this: user@shell:~/somedirectory$ ls -ld drwxr-xr-x 2014 K-rock users 65536 20011-11-05 11:34 user@shell:~/somedirectory$ ...
3
votes
2answers
156 views

How can I monitor a file that fully recreates during its run?

This is a follow-up question of Why are some file changes not shown in tail -f? With the use of capital F: tail -F I can monitor the output of tail -F ~/.mysql_history from the manual: ...
3
votes
1answer
1k views

Can't rename a directory that I own

I have a directory with a big load of sub directories. I own all of them, and the permissions are all 777. pascal@azazel /box $ ls -al total 147872 drwxr-xr-x 293 root root 12288 aoû 22 19:44 ...
2
votes
4answers
121 views

Can a running script identify the logging context?

Let us say I redirect the STDOUT, STDERR of a program to files. ./script.sh 1> output.log 2> error.log Can the running program find this out i.e. know the paths to these files?
2
votes
3answers
246 views

How to get a list of applications associated with a file using command line

File associations usually are made in the desktop environment, but how to get a list of applications associated with a file using command line? Something like: $ getassoc foo.pdf <CR> $ ...
2
votes
5answers
6k views

Get the newest file from directory structure year/month/date/time

I store backups of databases in a directory structure year/month/day/time/backup_name an example would be basics_mini/2012/11/05/012232/RATIONAL.0.db2inst1.NODE0000.20110505004037.001 ...
2
votes
2answers
778 views

How do I output a count of all files with “tty” in the filename in the Linux directory that holds files on system devices

I am having trouble knowing how to output a count of all files with “tty” in the filename in the Linux directory that holds files on system devices.
2
votes
1answer
176 views

Where can I find a reference to the format of the comment field (field 5) of the /etc/passwd file?

In the /etc/passwd file on my system, the "comment" field, field 5, is inconsistent in its contents. I thought that I could extract it to get the full name of the user. fullname=`awk -F: '$1 == name ...
2
votes
2answers
129 views

What file system is my file on? [duplicate]

How do I figure out which file system a given file/directory is located on? (For example, I would like to know if the file/directory is a temporary file in RAM, or if it's stored on disk. And what ...
1
vote
2answers
107 views

How do I move a line in a text file up or down by one line?

I have some text files, and I'd like to be able to move an arbitrary line in any of the files up or down one line (lines at the beginning or end of the file would stay where they are). I have some ...
0
votes
4answers
62 views

How does one inspect the directory structure information of a unix/linux file?

In Unix file systems directories are just special files with special directory structures that hold the child filename, filename size and inode reference number. The actual file metadata beyond ...
0
votes
1answer
503 views

Updating last modified time of a file

I have created a script to read 15 pcap files from a folder and merge then into one file using mergecap command. I want the merged file to have the creation time same as the first file of the 15 files ...
0
votes
1answer
113 views

How can number of subdirectories and files be determined from ls -ld command? [closed]

How can number of subdirectories and files be determined from the output of using ls -ld command? I realize that this command only lists the directories.