Logical entities that contain data in a filesystem. Use this tag if your question: is about programs that create files (e.g. gzip, tar, zip); deals with characteristics of files (permissions, size, path/location); or is about management of files (renaming, listing, moving, removing). For operating ...

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2
votes
1answer
74 views

Compress a tar file without extracting the content

Is it possible to compress a tar file such that I don't end up with an archive file in an other archive file but just an archive file containing my content fx. a tar.gz file? I don't want to extract ...
2
votes
2answers
340 views

Is reading a file on UNIX faster than writing a file?

Sorry for the sheer simplicity of this question. A rather obtuse performance bottleneck has boiled down to this very small query. I have done some empirical analysis and I think I might be getting ...
2
votes
3answers
71 views

What is the system-level effect of file permissions? [closed]

I know that r means read permission, w means write permission, and x means execute permission in the output of ls -l, like -rwxr-xr-x. But My question is what is behavior difference on operation ...
2
votes
3answers
407 views

File ID that doesn't change upon rename

I am trying to write a system utility script that will run as a cron job and capture file system statistics and environment settings in order to track as many changes as possible. Consider the ...
2
votes
3answers
100 views

How to know the path to a specific file in a zip archive, without extracting it?

I only know the filename but not its exact location. I would like to extract only that file from the archive. And I need to know its location in the archive.
2
votes
1answer
1k views

remove duplicate files in 2 directories

I have two folders (w/ subfolders) containing files that both contain essentially the same content. Example: /folder/files/data/new /folder/files/data/old Is there way to delete all files in /new ...
2
votes
4answers
219 views

Wrapper command that runs program in temporary directory and deletes it after execution [duplicate]

I want to write a command that: takes another command as its arguments does a 'cd' to a temporary folder executes the command passed in the arguments removes the temporary folder afterwards ...
2
votes
1answer
12k views

LS Command output to file [closed]

I want to capture to a file the output of the ls command ls >> lsOutput.log This one works if executed in the command line. But when put inside a shell script (lsOutput.sh), returns ./...
2
votes
2answers
309 views

How to change “date modified” of multiple folders, to be the same of that of a .mkv that's inside each one, using Cygwin

How to change "date modified" of multiple folders to be the same of that of the .mkv that's inside each one. eg. there's folder1 which contains a file 1.mkv folder1: 2/17/14 1.mkv: 1/6/12 I want ...
2
votes
3answers
441 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
2answers
90 views

Something like a symbolically linked file, but with change details attached?

Is there a file type or method for using files in which certain files look and behave like symbolically linked files, but contain extra meta information for changing the data when they are read? ...
2
votes
1answer
234 views

What does ^@^@^@ mean in a text file?

Sometimes I have problems with opening a file using a graphical text editor -- I'm using geany. The file can be read by vim without a problem. I checked the file, and there wasn't anything wrong with ...
2
votes
2answers
140 views

Keep track of all files accessed by a specific process?

There has recently been a (publicly unconfirmed) report that Skype is accessing files that it shouldn't be, without user intervention. I have no idea if this is the case with Skype on linux, but it ...
2
votes
1answer
711 views

Renaming files based on the contents of a text file

I have lots of point files I need to change for model input. I want to rename lots of these files based on the contents of a file. These files are text files arranged in rows. file name: ...
2
votes
3answers
960 views

zcat a file line by line? [closed]

I have written a C++ application that reads files line by line. It reads one line, does processing, then reads the next line. I would like to add support for gzipped files, and am looking to an ...
2
votes
2answers
129 views

how to count number of differences in large streams quickly?

I want to count the number of differences (different bytes) in two large streams (devices/files). E.g. two hard disks, or one hard disk and /dev/zero. The program(s) involved must be fast, as fast ...
2
votes
2answers
630 views

Matching two files for similar first line

I have 2 set of files. File one contains ID's ex: 1111 2222 6666 3333 4444 File two contains ID and username: 1873 Neil 1111 Roger 7632 Tim 3333 Oscar 8723 Greg 4444 Roy 6666 Patrick I want to ...
2
votes
3answers
503 views

How to cp or rm files based on ownership / permission

After a problem with spam, I stopped postfix postfix stop and checked through the mailq manually to find hundreds of thousands of unsent spam. The spam was sent from one of the sites hosted ...
2
votes
1answer
1k views

why cannot rename subdir when parent dir owner is not the same user [duplicate]

Possible Duplicate: Can’t rename a directory that I own I am trying to understand why when a dir X is owned by user A cannot rename it when parent dir of X is owned by user B. Can anyone ...
2
votes
2answers
91 views

'tie' [nonexisting] files to programs

Recently, I just had an idea which turned out to be pretty useful under certain circumstances. But first some simple explanation: In Perl, you have the option to tie variables to some functions ...
2
votes
2answers
1k views

Pre-defined umask under a given path [duplicate]

Possible Duplicate: How to set default file permissions for all folders/files in a directory? Say I have default umask, umask1. I would like all files/folders that I create/modify under a ...
2
votes
1answer
206 views

vim not shown in fuser

First use Vim to edit a file, say /tmp/A. Assuming that vim process is the only one that accesses /tmp/A, then use "ctrl+z" to suspend the process, and execute fuser /tmp/A Then you see nothing ...
2
votes
2answers
2k views

File delete versus overwrite and link at /proc/pid/fd

It is well known that UNIX systems won't actually delete a file on disk while the file is in use. So if a file is being accessed by process 1 and process 2 deletes the file using rm, process 1 ...
2
votes
2answers
134 views

How to generate folder ownership lists for each user?

I'd like to generate several separate lists for each user in Ubuntu. The lists contains the files and folders belong to each user. Using the command following list me all the users in the system: ...
2
votes
1answer
262 views

How are Flash Videos played?

I was tweaking around with a script for playing Youtube playlists in mplayer. My question is: How does linux play flash videos? My current research yields (By reading scripts written by others): ...
2
votes
1answer
249 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
1answer
107 views

Finding out *what* is synchronizing two Linux servers

The last person to maintain these Red Hat servers somehow set it up so they stay in sync -- if I delete files on one it automatically deletes them on the other. I need to set up a new configuration on ...
2
votes
2answers
2k views

Should I end my text/script files with a newline? [duplicate]

Possible Duplicate: What's the point in adding a new line to the end of a file? What is considered better behaviour: to leave the last letter of the last line to be the last byte of a file,...
2
votes
2answers
204 views

Splitting giant files into a specific number of lines

I have a CSV that is 40 000 lines long. What is the simplest tool to read from line x to line y? I am sure there are more professional ways to do it but I would just like a bash script that works in ...
2
votes
1answer
38 views

Can directories and file inherit same permissions as parent directory?

I want all directories and files to inherit same permissions as parent directory.
2
votes
2answers
44 views

Incorrect permissions on special files

I've noticed a lot of special files on Linux have what appears to be incorrect permissions: E.g.: $ ls -l /dev/fuse crw-rw-rw- 1 root root 10, 229 May 29 09:59 /dev/fuse appears writable but in ...
2
votes
1answer
32 views

Find differences of ownerships between two home folders?

I have two home folders: /home/masi and /home/masi_backup and I would like to find the differences between files of the two directories. Pseudocode vimdiff <`ls -la /home/masi` <`ls -la /home/...
2
votes
2answers
134 views

Lost Folders and Files in the directory /home/ubuntu/ in Ubuntu

I have uploaded a .tar file in /home/ubuntu/ and un-zipped the file in the folder name 'analytics'. After reboot, I couldn't found the directory and the tar files. I have checked it through SSH ...
2
votes
1answer
68 views

What happens when multiple processes try to mv the same files between two different filesystems

I accidentally launched 32 processes (one process per core on my virtual machine) to mv some files between two ext4 filesystems, but only some of them were successfully mv'd: for i in `seq 1 32`; do ...
2
votes
2answers
78 views

Extract a List of .zip files into one new directory each, directory name to be taken from name of the zip file

I have a folder containing many .zip files. They are named like this: John-Rupert A. Doe_nnnnnnn_assignsubmission_file_*.zip where n is a digit, * is a string and John-Rupert A. Doe is a string ...
2
votes
2answers
253 views

File merging - same name, different extension

How would you merge different input .txt and .tsv files (within a directory) who have the same name but a different extension into an output file? Input: file1.txt, file2.txt, file1.tsv, file2.tsv ...
2
votes
2answers
73 views

Find and replace all same files between 2 directories

I want to find all files in dir1 having corresponding same file names in dir2, and replace them with the files from dir2. For example: dir1: first.txt second.txt dir2: third.txt first.txt So I ...
2
votes
3answers
54 views

Recursively delete files with 'WIDTHxLENGTH' in the name in a directory

I have a directory that has subdirectories, and I want to delete images named like thumbnail-name_WIDTHxLENGTH.{jpg,png}, where WIDTH and LENGTH are both decimal integers, like box-image-150x150.jpg ...
2
votes
1answer
43 views

Why grep shows different results when I use file1 as a pattern on file2 and viceversa?

When I run grep -m 1 -Fnxvf file1 file2, for some couple of files I get a different line number than running grep -m 1 -Fnxvf file2 file1 (swapped files). Why? I've reduced the files to a minimal ...
2
votes
3answers
340 views

Difference between files in directory

I have two directories with same files but with some difference in their contents. I want to list down those files which are differing. For example There are two folders Folder1 and Folder2 with ...
2
votes
1answer
3k views

Permission denied writing to mysql log

I am just testing out a new Ubuntu (Vivid 15.04) install on Vagrant, and getting problems with mysql and logging to a custom location. In /var/log/syslog I get /usr/bin/mysqld_safe: cannot create /...
2
votes
3answers
162 views

Move file and preserve owner and mode in one atomic operation

Is there a way to move a file and preserve original owner(group) and file mode in one atomic operation? So there will not be change for others to access moved file in time when is not already set ...
2
votes
2answers
1k views

Copying latest file from remote server

There is a collection of .doc files, in addition to other types of files, on a remote server (which supports SCP). I am trying to write a script to retrieve the latest (most recently modified) .doc ...
2
votes
1answer
368 views

Seeing all regex matches in a file in Bash

I'm in bash and I have a file, I want to find all matches of a regex in it and have them printed. How do I do that? Followup: Assume I want to print only unique matches, i.e. if a match appears ...
2
votes
1answer
2k views

How can I check if rsync made any changes in bash?

I have a script which uses rsync to sync data in a remote -> local scenario. Immediately after the rsync command is run, a check to see if the error code equals zero or not. If its zero, further ...
2
votes
1answer
207 views

How to split file and save parts to multiple locations?

How do I split a large file into multiple smaller chunks and write each part of it into separate locations? split command seems to only output all the files into one location. The context I need to ...
2
votes
1answer
228 views

Using find and sed to copy 20th line of many files into one file

I have a folder called PKA1 Within this folder I have several folders named as: 1eV, 2eV .... 30eV Within each of these subfolders I have a file called PKA.dump I want to copy the 20th line of PKA....
2
votes
1answer
165 views

Why does chmod succeed on a file when the user does not have write permission on parent directory?

I am trying to understand file/dir permissions in Linux. A user can list the files in a directory using cd test ls -l Even if the user issuing above commands does not have read, write or execute ...
2
votes
1answer
107 views

Why am I seeing a number as owner / group instead a name?

CentOS 6.x / OpenVZ Recently my VPS provider moved my OpenVZ container to a new server. After that move, I've noticed that files/directories for one of my user accounts show an odd owner / group. ...
2
votes
2answers
281 views

Run a command with wildcards in each subdirectory

I use this command to make a montage of all the images in a directory: gmic *jpg -gimp_montage 4,\""V(H(0,1),H(2,V(3,4)))"\",1,1.0,0,5,0,0,0,255,0,0,0,0 -o -0000."$(date)".jpg I want to run this ...