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

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2
votes
2answers
112 views

What file system is my file on?

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 ...
0
votes
1answer
35 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
70 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.
32
votes
6answers
17k views

How can I edit multiple files in VIM?

I know I can open multiple files with vim by doing something like vim 2011-12*.log, but how can I switch between files and close the files one at a time? Also, how can I tell the file name of the ...
26
votes
2answers
1k views

Why does a software package run just fine even when it is being upgraded?

Say I am running a software, and then I run package manager to upgrade the software, I notice that Linux does not bring down the running process for package upgrade - it is still running fine. How ...
21
votes
3answers
4k views

Clone ownership and permissions from another file?

Is there a command or flag to clone the user/group ownership and permissions on a file from another file? To make the perms and ownership exactly "like" that of another file?
14
votes
6answers
15k views

How do I can get the size of a file in a bash script?

How do I can get the size of a file in a bash script? How do I assign this to a bash variable so I can use it later?
11
votes
2answers
372 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 ...
9
votes
3answers
4k views

List the files accessed by a program

time is a brilliant command if you want to figure out how much CPU time a given command takes. I am looking for something similar that can list the files being accessed by a program and its children. ...
5
votes
1answer
15k views

Where are Apache file access logs stored?

Does anyone know where file access logs are stored, so I can run a tail -f command in order to see who is accessing a particular file. I have XAMPP, which is an Apache server installed on my machine, ...
29
votes
3answers
16k views

How to tell gzip to keep original file?

I would like to compress a text file using gzip command line tool while keeping the original file. By default running the following command gzip file.txt results in modifying this file and renaming ...
20
votes
8answers
3k 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. ...
19
votes
2answers
1k views

How do I make a file NOT modifiable?

While logged in, I can do the following: mkdir foo touch foo/bar chmod 400 foo/bar chmod 500 foo Then I can open vim (not as root), edit bar, force a write with w!, and the file is modified! How ...
13
votes
2answers
384 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 ...
13
votes
4answers
5k views

How can I do a “copy if changed” operation?

I would like to copy a set of files from directory A to directory B, with the caveat that if a file in directory A is identical to a file in directory B, that file should not be copied (and thus its ...
7
votes
4answers
4k 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 ...
6
votes
1answer
156 views

How can I replace a string in a file(s)?

Replacing strings in files based on certain search criteria is a very common task. How can I replace string foo with bar in all files in the current directory? do the same recursively for sub ...
6
votes
7answers
7k 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 . ...
27
votes
3answers
86k 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 ...
12
votes
1answer
4k views

ls taking long time in small directory

Running Ubuntu, I open a terminal and do sudo bash cd / ls | head -n 1000 And predictably about 20 directories are returned. However, if I do an ls, and don't pipe it into anything, the ls just ...
7
votes
2answers
2k 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, ...
6
votes
4answers
1k views

List X random files from a directory

Is there a way to list a set of say, 30 random files from a directory using standard Linux commands? (in zsh) The top answer described here does not work for me (sort does not recognize the option ...
4
votes
0answers
159 views

Repeatably generate a read error for testing? [duplicate]

I'm trying to test the error handling in some software, in particular what happens when an error occurs reading from a file or pipe. Is there a simple way to send a certain amount of data to stdout ...
3
votes
2answers
97 views

How much text does grep/egrep consume each time?

I'm confused on grep/egrep. These tools match a single line I think? In some cases I have heard "logical" line. Questions Is it correct to assume that essentially grep/egrep always processes a ...
3
votes
2answers
2k views

Pseudo files for temporary data

I often want to feed relatively short string data (could be several lines though) to commandline programs which accept only input from files (e.g. wdiff) in a repeated fashion. Sure I can create one ...
2
votes
4answers
2k views

How do you write specific bytes to a file?

Given a file myfile with the following contents: $ cat myfile foos A hexdump of the file gives us the contents: $ hexdump myfile 6f66 736f 000a Currently, I can create the file by specifying the ...
10
votes
5answers
2k views

What's so special about directories whose names begin with a dot?

I was wondering what the difference between these two were: ~/somedirectory/file.txt and ~/.somedirectory/file.txt It's really difficult to ask this on Google since I didn't know how to explain ...
9
votes
5answers
10k views

Linux ls to show only filename date and size

How can I use ls in linux to get a listing of filenames date and size only. I don't need to see the other info such as owner or permission. Is this possible?
7
votes
1answer
2k 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 ...
5
votes
2answers
179 views

A virtual file containing the concatenation of other files

Is there a way of creating a filesystem object akin to this: mknod files p cat file1 file2 ... fileN > files but such that it can be seeked in, as if it were a regular file?
5
votes
3answers
207 views

Dynamic file content generation: Satisfying a 'file open' by a 'process execution'

I have a read-only file, F. A program, P, that I'm not the author of, needs to read F. I want the content of F to come from another 'generator' program, G, whenever P tries to read F (taking F to ...
5
votes
2answers
509 views

A command line utility to visualize how fast a file is growing?

I want to grok how fast a particular file is growing. I could do watch ls -l file And deduce this information from the rate of change. Is there something similar that would directly output the ...
5
votes
2answers
2k views

Unpack files and directories from an image created by dd?

I created an image of an NTFS partition using dd. I wonder if I can unload/unpack the files and directories in the image to any partition whose size is larger than the image size, so that I can ...
5
votes
2answers
810 views

How to grep on source code without catching comments

I search a way to grep on source code without having sometimes false-positive because of comments. For instance if I search on foo on this .c source code : /* * foo has changed [...] and is now a ...
4
votes
1answer
202 views

Changing a file's “Date Created” and “Last Modified” attributes to another file's

I'm using merge cap to create a merge pcap file from 15 files. For the merged file, I have changed the name to that of the first of the 15 files. But I would also like to change the merged file's ...
4
votes
3answers
2k 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 ...
4
votes
2answers
365 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
2answers
89 views

Search by file dimension [duplicate]

I have many photos. How to search files by its dimensions? For example, i want to search images with exact dimensions 500 x 500 pixels. Is there any utility for this task?
3
votes
4answers
4k views

Move all files with a certain extension from multiple subdirectories into one directory

Suppose I have a bunch of zip files in several directories: Fol1/Fol2 Fol3 Fol4/Fol5 And I want to move them all to a common base folder. How would I do this?
3
votes
2answers
1k views

Obtain .avi file info from command line

What is the best way to obtain information as bitrate, framerate, width/height of an movie file (in my case .avi) from the command line? I am looking for a basic tool that works similarly as ...
2
votes
3answers
148 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?
2
votes
1answer
1k views

single bind mounted file gets out of sync in linux

I am bind mounting a single file on top of another one and after making changes with an editor, I don't see the modifications in both files. However, if I make the changes with the shell using ...
1
vote
1answer
3k views

How to add 'open folder as root' in Elementary OS file manager context menu?

Here it is the solution in order to add the 'open terminal here' into the context menu of Elementary OS' file manager (generically called 'Files' - the executable is pantheon-files). For that ...
1
vote
2answers
2k views

How to write a file at various offsets to a filesystem partition with dd command

Requirement I want to write a file at various offsets into the partition Partition /dev/part2 is mounted at /mypart I tried the command below: dd if=/dev/urandom of=/mypart/aaa bs=1024 seek=0 ...
11
votes
2answers
962 views

“ls -lh” reports total size less than sum of individual sizes

Under what circumstances would ls -lh show a total that is less than the sum of the individual files? For example: $ ls -lh /var/lib/nova/instances/_base total 100G -rw-rw-r-- 1 nova nova ...
9
votes
2answers
193 views

How to start tailing a file that has not been yet created

I use tail to monitor the progress of jobs that I know will write their progress to disk. Almost always, I know which file they will create before they start running (the jobs are dispatched by a ...
7
votes
2answers
1k views

How can I cut a large file in place?

I have a very big text file, about 80GB, and I need to cut a part form it that lies between two given lines. The part I need is not big, and I have not enough space left on the hard drive to do things ...
7
votes
4answers
4k 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
6answers
145 views

File protection in Unix

Is there a way to protect a file in such a way that even root cannot delete it or rewrite it after creating it? I have a file which is created by root under /var/log/ and I want to restrict all users ...
5
votes
2answers
104 views

Difference between xattr and chattr

What is the relation and the difference between xattr and chattr? I want to know when I set a chattr attribute in Linux what is happening inside the Linux kernel and inode metadata.