Copy N random files from folder A to folder B in ruby - ruby

Suppose folder A contains 2000 files of same type.
I would like to copy 1000 random files from folder A to folder B.
what is the easiest way to do that in Ruby!!
Thanks!
S

Hints :
Dir.entries(<dir>) gives the list of filenames in the given directory as an array.
Array#sample(n) gives you n random elements taken from the array.
FileUtils.cp(<src>, <dest>) helps you copy a file from a dir to another (you need to require fileutils for this though.

Related

How to loop over multiple folders to concatenate FastQ files?

I have received multiple fastq.gz files from Illumina Sequencing for 100 samples. But all the fastq.gz files for the respective samples are in separate folders according to the sample ID. Moreover, I have multiple (8-16) R1.fastq.gz and R2.fastq.gz files for one sample. So, I used the following code for concatenating all the R1.fastq.gz and R2.fastq.gz into a single R1.fastq.gz and R2.fastq.gz.
cat V350043117_L04_some_digits-525_1.fq.gz V350043117_L04_some_digits-525_1.fq.gz V350043117_L04_some_digits-525_1.fq.gz > sample_R1.fq.gz
So in the sequencing file, the structure is like the above in the code. For each sample, the string with V has different number then L with different number and then another string of digits before the _1 and _2. For each sample, the numbers keep changing.
My questing is, how can I create a loop that will go over all the folders at once taking the different file numbering of sequence files into consideration for concatenating the multiple fq.gz files and combine them into a single R1 and R2 file?
Surely, I cannot just concatenate one by one by going into each sample folder.
Please give some helpful tips. Thank you.
The folder structure is the following:
/data/Sample_1/....._525_1_fq.gz /....._525_2_fq.gz /....._526_1_fq.gz /....._526_2_fq.gz
/data/Sample_2/....._580_1_fq.gz /....._580_2_fq.gz /....._589_1_fq.gz /....._589_2_fq.gz
/data/Sample_3/....._690_1_fq.gz /....._690_2_fq.gz /....._645_1_fq.gz /....._645_2_fq.gz
Below I have attached a screenshot of the folder structure.
Folder structure
Based on the provided file structure, would you please try:
#!/bin/bash
for d in Raw2/C*/; do
(
cd "$d"
id=${d%/}; id=${id##*/} # extract ID from the directory name
cat V*_1.fq.gz > "${id}_R1.fq.gz"
cat V*_2.fq.gz > "${id}_R2.fq.gz"
)
done
The syntax for d in Raw2/C*/ loops over the subdirectories starting with C.
The parentheses make the inner commands executed in a subshell so we don't have to care about returning from cd "$d" (at the expense of small extra execution time).
The variable id is assigned to the ID extracted from the directory name.
cat V*_1.fq.gz, for example, will be expanded as V350028825_L04_581_1.fq.gz V350028825_L04_582_1.fq.gz V350028825_L04_583_1.fq.gz ... according to the files in the directory and are concatenated into ${id}_R1.fastq.gz. Same for ${id}_R2.fastq.gz.

How to find duplicate directories

Let create some testing directory tree:
#!/bin/bash
top="./testdir"
[[ -e "$top" ]] && { echo "$top already exists!" >&2; exit 1; }
mkfile() { printf "%s\n" $(basename "$1") > "$1"; }
mkdir -p "$top"/d1/d1{1,2}
mkdir -p "$top"/d2/d1some/d12copy
mkfile "$top/d1/d12/a"
mkfile "$top/d1/d12/b"
mkfile "$top/d2/d1some/d12copy/a"
mkfile "$top/d2/d1some/d12copy/b"
mkfile "$top/d2/x"
mkfile "$top/z"
The structure is: find testdir \( -type d -printf "%p/\n" , -type f -print \)
testdir/
testdir/d1/
testdir/d1/d11/
testdir/d1/d12/
testdir/d1/d12/a
testdir/d1/d12/b
testdir/d2/
testdir/d2/d1some/
testdir/d2/d1some/d12copy/
testdir/d2/d1some/d12copy/a
testdir/d2/d1some/d12copy/b
testdir/d2/x
testdir/z
I need find the duplicate directories, but I need consider only files (e.g. I should ignore (sub)directories without files). So, from the above test-tree the wanted result is:
duplicate directories:
testdir/d1
testdir/d2/d1some
because in both (sub)trees are only two identical files a and b. (and several directories, without files).
Of course, I could md5deep -Zr ., also could walk the whole tree using perl script (using File::Find+Digest::MD5 or using Path::Tiny or like.) and calculate the file's md5-digests, but this doesn't helps for finding the duplicate directories... :(
Any idea how to do this? Honestly, I haven't any idea.
EDIT
I don't need working code. (I'm able to code myself)
I "just" need some ideas "how to approach" the solution of the problem. :)
Edit2
The rationale behind - why need this: I have approx 2.5 TB data copied from many external HDD's as a result of wrong backup-strategy. E.g. over the years, the whole $HOME dirs are copied into (many different) external HDD's. Many sub-directories has the same content, but they're in different paths. So, now I trying to eliminate the same-content directories.
And I need do this by directories, because here are directories, which has some duplicates files, but not all. Let say:
/some/path/project1/a
/some/path/project1/b
and
/some/path/project2/a
/some/path/project2/x
e.g. the a is a duplicate file (not only the name, but by the content too) - but it is needed for the both projects. So i want keep the a in both directories - even if they're duplicate files. Therefore me looking for a "logic" how to find duplicate directories.
Some key points:
If I understand right (from your comment, where you said: "(Also, when me saying identical files I mean identical by their content, not by their name)" , you want find duplicate directories, e.g. where their content is exactly the same as in some other directory, regardless of the file-names.
for this you must calculate some checksum or digest for the files. Identical digest = identical file. (with great probability). :) As you already said, the md5deep -Zr -of /top/dir is a good starting point.
I added the -of, because for such job you don't want calculate the contents of the symlinks-targets, or other special files like fifo - just plain files.
calculating the md5 for each file in 2.5TB tree, sure will take few hours of work, unless you have very fast machine. The md5deep runs a thread for each cpu-core. So, while it runs, you can make some scripts.
Also, consider run the md5deep as sudo, because it could be frustrating if after a long run-time you will get some error-messages about unreadable files, only because you forgot to change the files-ownerships...(Just a note) :) :)
For the "how to":
For comparing "directories" you need calculate some "directory-digest", for easy compare and finding duplicates.
The one most important thing is realize the following key points:
you could exclude directories, where are files with unique digests. If the file is unique, e.g. has not any duplicates, that's mean that is pointless checking it's directory. Unique file in some directory means, that the directory is unique too. So, the script should ignore every directory where are files with unique MD5 digests (from the md5deep's output.)
You don't need calculate the "directory-digest" from the files itself. (as you trying it in your followup question). It is enough to calculate the "directory digest" using the already calculated md5 for the files, just must ensure that you sort them first!
e.g. for example if your directory /path/to/some containing only two files a and b and
if file "a" has md5 : 0cc175b9c0f1b6a831c399e269772661
and file "b" has md5: 92eb5ffee6ae2fec3ad71c777531578f
you can calculate the "directory-digest" from the above file-digests, e.g. using the Digest::MD5 you could do:
perl -MDigest::MD5=md5_hex -E 'say md5_hex(sort qw( 92eb5ffee6ae2fec3ad71c777531578f 0cc175b9c0f1b6a831c399e269772661))'
and will get 3bc22fb7aaebe9c8c5d7de312b876bb8 as your "directory-digest". The sort is crucial(!) here, because the same command, but without the sort:
perl -MDigest::MD5=md5_hex -E 'say md5_hex(qw( 92eb5ffee6ae2fec3ad71c777531578f 0cc175b9c0f1b6a831c399e269772661))'
produces: 3a13f2408f269db87ef0110a90e168ae.
Note, even if the above digests aren't the digests of your files, but they're will be unique for every directory with different files and will be the same for the identical files. (because identical files, has identical md5 file-digest). The sorting ensures, that you will calculate the digest always in the same order, e.g. if some other directory will contain two files
file "aaa" has md5 : 92eb5ffee6ae2fec3ad71c777531578f
file "bbb" has md5 : 0cc175b9c0f1b6a831c399e269772661
using the above sort and md5 you will again get: 3bc22fb7aaebe9c8c5d7de312b876bb8 - e.g. the directory containing same files as above...
So, in such way you can calculate some "directory-digest" for every directory you have and could be ensured that if you get another directory digest 3bc22fb7aaebe9c8c5d7de312b876bb8 thats means: this directory has exactly the above two files a and b (even if their names are different).
This method is fast, because you will calculate the "directory-digests" only from small 32bytes strings, so you avoids excessive multiple file-digest-caclulations.
The final part is easy now. Your final data should be in form:
3a13f2408f269db87ef0110a90e168ae /some/directory
16ea2389b5e62bc66b873e27072b0d20 /another/directory
3a13f2408f269db87ef0110a90e168ae /path/to/other/directory
so, from this is easy to get: the
/some/directory and the /path/to/other/directory are identical, because they has identical "directory-digests".
Hm... All the above is only a few lines long perl script. Probably would be faster to write here directly the perl-script as the above long textual answer - but, you said - you don't want code... :) :)
A traversal can identify directories which are duplicates in the sense you describe. I take it that this is: if all files in a directory are equal to all files of another then their paths are duplicates.
Find all files in each directory and form a string with their names. You can concatenate the names with a comma, say (or some other sequence that is certainly not in any names). This is to be compared. Prepend the path to this string, so to identify directories.
Comparison can be done for instance by populating a hash with keys being strings with filenames and path their values. Once you find that a key already exists you can check the content of files, and add the path to the list of duplicates.
The strings with path don't have to be actually formed, as you can build the hash and dupes list during the traversal. Having the full list first allows for other kinds of accounting, if desired.
This is altogether very little code to write.
An example. Let's say that you have
dir1/subdir1/{a,b} # duplicates (files 'a' and 'b' are considered equal)
dir2/subdir2/{a,b}
and
proj1/subproj1/{a,b,X} # NOT duplicates, since there are different files
proj2/subproj2/{a,b,Y}
The above prescription would give you strings
'dir1/subdir1/a,b',
'dir2/subdir2/a,b',
'proj1/subproj1/a,b,X',
'proj2/subproj2/a,b,Y';
where the (sub)string 'a,b' identifies dir1/subdir1 and dir2/subdir2 as duplicates.
I don't see how you can avoid a traversal to build a system that accounts for all files.
The procedure above is the first step, not handling directories with files and subdirectories.
Consider
dirA/ dirB/
a b sdA/ a X sdB/
c d c d
Here the paths dirA/sdA/ and dirB/sdB/ are duplicates by the problem description but the whole dirA/ and dirB/ are distinct. This isn't shown in the question but I'd expect it to be of interest.
The procedure from the first part can be modified for this. Iterate through directories, forming a path component at every step. Get all files in each, and all subdirectories (if none we are done). Append the comma-separated file list to the path component (/sdA/). So the representation of the above is
'dirA/sdA,a,b/c,d', 'dirB/sdB,a,X/c,d'
For each file-list substring (c,d) found to already exist we can check its path against the existing one, component by component. Now a hash with keys like c,d won't do since this example has the same file-list for distinct hierarchies, but a modified (or other) data structure is needed.
Finally, there may be more subdirectories parallel to sdA (say sdA2). We care only for its own path, but except for the parallel files (a,b, in that component of the path dirA/sdaA2,a,b/). So keep in mind all bottom-level file-lists (c,d) with their paths and, if file-lists are equal and paths are of same length, check whether their paths have a,b file-lists equal in each path component.
I don't know whether this is a workable solution for you, but I'd expect "near-duplicates" to be rare -- the backup is either a duplicate or not. So there may not be much need to handle futher edge-cases in complex sprawling hierarchies. This procedure should be at least a useful pre-selection mechanism, that would greatly reduce the need for further work.
This assumes that equal file-names very likely indicate equal files. A part of that is my expectation that if a file was even just renamed it still cannot be considered a duplicate. If this is not so this approach won't work and one would need something along the lines of the answer by jm666.
I make a tool which searches duplicate folders.
https://github.com/un1t/dirdups
dirdups testdir -i 1
-i 1 option consider folders as duplicates if they have at least 1 file in common. Without this option default value is 10.
In your case it will find the following directories:
testdir/d1/d12/
testdir/d2/d1some/d12copy/

Extracting contents of many zipped folders into a single directory

Kind of easy question, but I can't find the answer. I want to extract the contents of multiple zipped folders into a single directory. I am using the bash console, which is the only tool available on the particular website I am using.
For example, I have two folders: a.zip (which contains a1.txt and a2.txt) and b.zip (which contains b1.txt and b2.txt). I want to get extract all four text files into a single directory.
I have tried
unzip \*.zip -d \newdirectory
But it creates two directories (a and b) with two text files in each.
I also tried concatenating the two zipped folders into one big folder and extracting it, but it still creates two directories, even when I specify a new directory.
I can't figure what I am doing wrong. Any help?
Thanks in advance!
Use the -j parameter to ignore any directory structure.
unzip -j -d /path/to/your/directory '*.zip*'

Recursively copy file-types from directory tree

I'm trying to find a way to copy all *.exe files (and more, *.dtd, *.obj, etc.) from a directory structure to another path.
For example I might have:
Code
\classdirA
\bin
\classA.exe
\classdirB
\bin
\classB.exe
\classdirC
\bin
\classC.exe
\classdirD
\bin
\classD.exe
And I want to copy all *.exe files into a single directory, say c:\bins
What would be the best way to do this?
Constraints for my system are:
Windows
Can be Perl, Ruby, or .cmd
Anyone know what I should be looking at here?
Just do in Ruby, using method Dir::glob :
# this will give you all the ".exe" files recursively from the directory "Code".
Dir.glob("c:/Code/**/*.exe")
** - Match all directories recursively. This is used to descend into the directory tree and find all files in sub-directories of the current directory, rather than just files in the current directory. This wildcard is explored in the example code.
* - Match zero or more characters. A glob consisting of only the asterisk and no other characters or wildcards will match all files in the current directory. The asterisk is usually combined with a file extension, if not more characters to narrow down the search.
Nice blog Using Glob with Directories.
Now to copy the files to your required directory, you need to look into the method, FileUtils.cp_r :
require 'fileutils'
FileUtils.cp_r Dir.glob("c:/Code/**/*.exe"), "c:\\bins"
I just have tested, that FileUtils.cp method will also work, in this case :
require 'fileutils'
FileUtils.cp Dir.glob("c:/Code/**/*.exe"), "c:\\bins"
My preference here is to use ::cp method. Because Dir::glob is actually collecting all the files having .exe extensions recursively, and return them as an array. Now cp method is enough here, now just taking each file from the array and coping it to the target file.
Why I am not liking in such a situation, the method ::cp_r ?
Okay, let me explain it here also. As the method name suggests, it will copy all the files recursively from the source to target directory. If there is a need to copy specific files recursively, then ::cp_r wouldn't be able to do this by its own power ( as it can't do selections by itself, which ::glob can do ). Thus in such a situation, you have to give it the specific file lists, it would then copy then to the target directory. If this is the only task, I have to do, then I think we should go with ::cp, rather than ::cp_r.
Hope my explanation helps.
From cmd command line
for /r "c:\code" %f in (*.exe) do copy "%~ff" "c:\bins"
For usage inside a batch file, double the percent signs (%% instead of %)
Windows shell (cmd) command:
for /r code %q in (*.exe) do copy "%q" c:\bin
Double the % characters if you place this in a batch file.

How to read images from folders in matlab

I have six folders like this >> Images
and each folder contains some images. I know how to read images in matlab BUT my question is how I can traverse through these folders and read images in abc.m file (this file is shown in this image)
So basically you want to read images in different folders without putting all of the images into one folder and using imread()? Because you could just copy all of the images (and name them in a way that lets you know which folder they came from) into a your MATLAB working directory and then load them that way.
Use the cd command to change directories (like in *nix) and then load/read the images as you traverse through each folder. You might need absolute path names.
The easiest way is certainly a right clic on the forlder in matlab and "Add to Path" >> "Selected Folders and Subfolders"
Then you can just get images with imread without specifying the path.
if you know the path to the image containing directory, you can use dir on it to list all the files (and directories) in it. Filter the files with the image extension you want and voila, you have an array with all the images in the directory you specified:
dirname = 'images';
ext = '.jpg';
sDir= dir( fullfile(dirname ,['*' ext]) );;
sDir([sDir.isdir])=[]; % remove directories
% following is obsolete because wildcarded dir ^^
b=arrayfun(#(x) strcmpi(x.name(end-length(ext)+1:end),ext),sDir); % filter on extension
sFiles = sDir(b);
You probably want to prefix the name of each file with the directory before using:
sFileName(ii) = fullfile(dirname, sFiles(ii));
You can process this resulting files as you want. Loading all the files for example:
for ii=1:numel(sFiles)
data{i}=imread(sFiles(ii).name)
end
If you also want to recurse the subdirectories, I suggest you take a look at:
How to get all files under a specific directory in MATLAB?
or other solutions on the FEX:
http://www.mathworks.com/matlabcentral/fileexchange/8682-dirr-find-files-recursively-filtering-name-date-or-bytes
http://www.mathworks.com/matlabcentral/fileexchange/15505-recursive-dir
EDIT: added Amro's suggestion of wildcarding the dir call

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