Linux concat binary files

Fastest way to concatenate files

I’ve got 10k+ files totaling over 20GB that I need to concatenate into one file.

Is there a faster way than

The preferred way would be a bash command, Python is acceptable too if not considerably slower.

2 Answers 2

Nope, cat is surely the best way to do this. Why use python when there is a program already written in C for this purpose? However, you might want to consider using xargs in case the command line length exceeds ARG_MAX and you need more than one cat . Using GNU tools, this is equivalent to what you already have:

Allocating the space for the output file first may improve the overall speed as the system won’t have to update the allocation for every write.

For instance, if on Linux:

Another benefit is that if there’s not enough free space, the copy will not be attempted.

If on btrfs , you could copy —reflink=always the first file (which implies no data copy and would therefore be almost instantaneous), and append the rest. If there are 10000 files, that probably won’t make much difference though unless the first file is very big.

There’s an API to generalise that to ref-copy all the files (the BTRFS_IOC_CLONE_RANGE ioctl ), but I could not find any utility exposing that API, so you’d have to do it in C (or python or other languages provided they can call arbitrary ioctl s).

If the source files are sparse or have large sequences of NUL characters, you could make a sparse output file (saving time and disk space) with (on GNU systems):

Источник

How to append contents of multiple files into one file

I want to copy the contents of five files to one file as is. I tried doing it using cp for each file. But that overwrites the contents copied from the previous file. I also tried

and it did not work.

I want my script to add the newline at the end of each text file.

eg. Files 1.txt, 2.txt, 3.txt. Put contents of 1,2,3 in 0.txt

11 Answers 11

You need the cat (short for concatenate) command, with shell redirection ( > ) into your output file

Another option, for those of you who still stumble upon this post like I did, is to use find -exec :

In my case, I needed a more robust option that would look through multiple subdirectories so I chose to use find . Breaking it down:

Look within the current working directory.

Only interested in files, not directories, etc.

Whittle down the result set by name

Execute the cat command for each result. «+» means only 1 instance of cat is spawned (thx @gniourf_gniourf)

As explained in other answers, append the cat-ed contents to the end of an output file.

if you have a certain output type then do something like this

If all your files are in single directory you can simply do

Files 1.txt,2.txt, .. will go into 0.txt

If all your files are named similarly you could simply do:

I found this page because I needed to join 952 files together into one. I found this to work much better if you have many files. This will do a loop for however many numbers you need and cat each one using >> to append onto the end of 0.txt.

as brought up in the comments:

Another option is sed :

Or without redirection .

Note that last line write also merge.txt (not wmerge.txt !). You can use w»merge.txt» to avoid confusion with the file name, and -n for silent output.

Of course, you can also shorten the file list with wildcards. For instance, in case of numbered files as in the above examples, you can specify the range with braces in this way:

if your files contain headers and you want remove them in the output file, you can use:

If the original file contains non-printable characters, they will be lost when using the cat command. Using ‘cat -v’, the non-printables will be converted to visible character strings, but the output file would still not contain the actual non-printables characters in the original file. With a small number of files, an alternative might be to open the first file in an editor (e.g. vim) that handles non-printing characters. Then maneuver to the bottom of the file and enter «:r second_file_name». That will pull in the second file, including non-printing characters. The same could be done for additional files. When all files have been read in, enter «:w». The end result is that the first file will now contain what it did originally, plus the content of the files that were read in.

All of the (text-) files into one

xargs makes the output-lines of find . the arguments of cat.

find has many options, like -name ‘*.txt’ or -type.

you should check them out if you want to use it in your pipeline

If you want to append contents of 3 files into one file, then the following command will be a good choice:

It will combine the contents of all files into file4, throwing console output to /dev/null .

Not the answer you’re looking for? Browse other questions tagged linux bash unix or ask your own question.

Linked

Related

Hot Network Questions

Subscribe to RSS

To subscribe to this RSS feed, copy and paste this URL into your RSS reader.

site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2021.10.8.40416

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.

Источник

Concatenating multiple text files into a single file in Bash

What is the quickest and most pragmatic way to combine all *.txt file in a directory into one large text file?

Currently I’m using windows with cygwin so I have access to BASH.

Windows shell command would be nice too but I doubt there is one.

12 Answers 12

This appends the output to all.txt

This overwrites all.txt

Just remember, for all the solutions given so far, the shell decides the order in which the files are concatenated. For Bash, IIRC, that’s alphabetical order. If the order is important, you should either name the files appropriately (01file.txt, 02file.txt, etc. ) or specify each file in the order you want it concatenated.

The Windows shell command type can do this:

Type type command also writes file names to stderr, which are not captured by the > redirect operator (but will show up on the console).

You can use Windows shell copy to concatenate files.

To append files, specify a single file for destination, but multiple files for source (using wildcards or file1+file2+file3 format).

Be careful, because none of these methods work with a large number of files. Personally, I used this line:

EDIT: As someone said in the comments, you can replace $(ls | grep «.txt») with $(ls *.txt)

EDIT: thanks to @gnourf_gnourf expertise, the use of glob is the correct way to iterate over files in a directory. Consequently, blasphemous expressions like $(ls | grep «.txt») must be replaced by *.txt (see the article here).

Источник

How to Combine Text Files Using the “cat” Command in Linux

Lori Kaufman is a technology expert with 25 years of experience. She’s been a senior technical writer, worked as a programmer, and has even run her own multi-location business. Read more.

The cat command is very useful in Linux. It has three main functions related to manipulating text files: creating them, displaying them, and combining them.

We’ve discussed using the cat command (among others) to create and view text files on the command line in Linux. But let’s assume you have three text files: file1.txt, file2.txt, and file3.txt. You want to combine (or concatenate) them into one text file containing information from all three, in that order. You can do this with the cat command as well.

Simply open a Terminal and type the following command:

Obviously, replace the file names in the above example with your own.

The combined contents of the three text files will appear in your terminal.

Typically, though, you’ll probably want to combine those text files into another text file, not just print the results to the screen. Luckily, this is very simple. All you need to do is add an output redirection symbol ( > ) after the list of files being concatenated, and then specify the name of the final text file.

NOTE: The file listed after the output redirection symbol will be overwritten, if it already exists. So, be careful when specifying the name of the combined text file. We’ll show you later in this article how to append files to the end of an existing file.

If you open file4.txt (either with the cat command or with the text editor of your choice), you should find that it contains the text of the first three text files.

If you’re combining lists of items from multiple files and you want them alphabetized in the combined file, you can sort the combined items in the resulting file. To do this, enter the basic cat command we previously showed you followed by the pipe command (|) and the sort command. Then, type the output redirection symbol ( > ) followed by the name of the file into which you want to copy the combined text. All the lines of text in the result file will be sorted alphabetically.

As we mentioned earlier, there is also a way append files to the end of an existing file. Type the cat command followed by the file or files you want to add to the end of an existing file. Then, type two output redirection symbols ( >> ) followed by the name of the existing file you want to add to.

If you want to add a bit of new text to an existing text file, you use the cat command to do it directly from the command line (instead of opening it in a text editor). Type the cat command followed by the double output redirection symbol ( >> ) and the name of the file you want to add text to.

A cursor will appear on the next line below the prompt. Start typing the text you want to add to the file. When you’re done, press Enter after the last line and then press Ctrl+D to copy that text to the end of the file and quit cat.

If you end up with a very long file once you combine your text files, you can use the pipe symbol with the less command when viewing the file in the Terminal window. For example, cat file4.txt | less . We discuss using the less command in this article.

Источник

Linux Concat Binary Files

Related Searches

Listing Of Websites About linux concat binary files

Linux utility to combine two or more binary files into a .

Posted at: 1 week ago | Categories: FAQs | 362 People Used View Detail

bash — How can I copy several binary files into one file .

Posted at: 2 days ago | Categories: FAQs | 308 People Used View Detail

Unix / Linux: Concatenate Multiple Files — Stack Pointer

Posted at: 1 week ago | Categories: FAQs | 254 People Used View Detail

concatenate binary files. — linuxquestions.org

Posted at: 1 week ago | Categories: FAQs | 280 People Used View Detail

linux — Can we merge binary files without any copy .

Posted at: 5 days ago | Categories: FAQs | 225 People Used View Detail

linux — What’s the best way to join files again after .

Posted at: 1 week ago | Categories: FAQs | 464 People Used View Detail

how to merge multiple files into one single file in linux .

Posted at: 2 days ago | Categories: FAQs | 433 People Used View Detail

10 ways to analyze binary files on Linux | …

Posted at: 1 week ago | Categories: FAQs | 70 People Used View Detail

bin — How to join two binary files on Windows — Stack …

Posted at: 5 days ago | Categories: FAQs | 431 People Used View Detail

Linux Concat Binary Files Images

Posted at: 2 days ago | Categories: FAQs | 377 People Used View Detail

How to Combine Text Files Using the “cat” Command …

Posted at: 6 days ago | Categories: FAQs | 168 People Used View Detail

Concatenating Text Files into a Single File in Linux .

Posted at: 1 week ago | Categories: FAQs | 429 People Used View Detail

Cat Command in Linux: Essential and Advanced Examples

Posted at: 6 days ago | Categories: FAQs | 311 People Used View Detail

How to Peek Inside Binary Files From the Linux …

Posted at: 6 days ago | Categories: FAQs | 216 People Used View Detail

[Solved] Concatenate large number of binary files .

2-6Kb) files that i wish to concatenate into one large file. I tried using a PowerShell script using Get-Content and Add-Content, but that was agonisingly slow. Does anyone know of a relatively fast way of doing this using either a PowerShell script, some other system commands, or a small .

Posted at: 1 week ago | Categories: FAQs | 60 People Used View Detail

command line — Concatenate multiple files without …

Posted at: 5 days ago | Categories: FAQs | 478 People Used View Detail

How To Split And Combine Files From Command Line …

Posted at: 1 week ago | Categories: FAQs | 201 People Used View Detail

cat Command in Linux / Unix with examples — nixCraft

What Is

Posted at: 1 week ago | Categories: What Is | 261 People Used View Detail

Cat command in Linux with examples — GeeksforGeeks

Posted at: 1 week ago | Categories: FAQs | 425 People Used View Detail

Joining two or more binary files together — UNIX

URL: https://www.unix.com/. /25034-joining-two-more-binary-files-together.html Go now

Posted at: 4 days ago | Categories: FAQs | 410 People Used View Detail

Windows: `Cat` Equivalent – CMD & PowerShell — …

Posted at: 1 week ago | Categories: FAQs | 186 People Used View Detail

Join (merge / concatenate) split files: Windows or …

Posted at: 1 week ago | Categories: FAQs | 342 People Used View Detail

Bash Concatenate Strings | Linuxize

Posted at: 3 days ago | Categories: FAQs | 119 People Used View Detail

linux — How do I append a specific number of null …

]# hexdump -C test |tail -5 000003e0 0a 0a 3d 3d 3d 3d 3e 20 54 65 78 74 20 6f 66 20 .

Posted at: 5 days ago | Categories: FAQs | 275 People Used View Detail

Linux Command Line Cheat Sheet — …

Posted at: 1 week ago | Categories: FAQs | 383 People Used View Detail

Linux strings command — javatpoint

Posted at: 6 days ago | Categories: FAQs | 255 People Used View Detail

Use CAT Command to Combine Text Files in Ubuntu …

Posted at: 3 days ago | Categories: FAQs | 471 People Used View Detail

Related Searches

How to concatenate two files into one in Linux?

Objective: Concatenate or append multiple text or binary files into a single file on Unix / Linux. If you have two files, foo1.txt and foo2.txt and if you want to concatenate the two files into foo.txt, you can use the cat command. The above command works for both text and binary files.

How to concatenate large number of binary files?

I have a large number (

2-6Kb) files that i wish to concatenate into one large file. I tried using a PowerShell script using Get-Content and Add-Content, but that was agonisingly slow.

How can I use cat to concatenate two files?

If we use the command the same way, but give it two or more files, then it outputs the concatenation for the files. If we run the following commands: The output is the contents of the 1st file, followed by the contents of the 2nd file. You can give cat many files and it will concatenate (combine) all of them.

How to use cat command with binary files?

That way, you can insert the data read from the standard input between the files given on the command line: B. Using cat command with binary files 1. Joining split files The cat command does not make any assumption about the file content, so it will happily work with binary data.

Источник