How to Tell Binary from Text Files in Linux

How to check if the file is a binary file and read all the files which are not?

Use utility file, sample usage:

 $ file /bin/bash
 /bin/bash: Mach-O universal binary with 2 architectures
 /bin/bash (for architecture x86_64):   Mach-O 64-bit executable x86_64
 /bin/bash (for architecture i386): Mach-O executable i386

 $ file /etc/passwd
 /etc/passwd: ASCII English text

 $ file code.c
 code.c: ASCII c program text

file manual page

How to tell binary from text files in linux

The diff manual specifies that

diff determines whether a file is text
or binary by checking the first few
bytes in the file; the exact number of
bytes is system dependent, but it is
typically several thousand. If every
byte in that part of the file is
non-null, diff considers the file to
be text; otherwise it considers the
file to be binary.

How do I distinguish between 'binary' and 'text' files?

The spreadsheet software my company makes reads a number of binary file formats as well as text files.

We first look at the first few bytes for a magic number which we recognize. If we do not recognize the magic number of any of the binary types we read, then we look at up to the first 2K bytes of the file to see whether it appears to be a UTF-8, UTF-16 or a text file encoded in the current code page of the host operating system. If it passes none of these tests, we assume that it is not a file we can deal with and throw an appropriate exception.

How to view files in binary from bash?

xxd does both binary and hexadecimal.

bin:

xxd -b file

hex:

xxd file

How can I extract the text portion of a binary file in Linux/Bash?

Use the strings utility - that's exactly what it's designed for.

which command can be used to determine if a file is binary

grep is simply looking for non-ASCII content for its "binary" determination. You can trivially override this with the -a flag, to assume that all content is text:

grep -a "Notifying status" -R

How to convert a text file containing hexadecimal to binary file using linux commands?

use xxd -r. it reverts a hexdump to its binary representation.

source and source

Edit: The -p parameter is also very useful. It accepts "plain" hexadecimal values, but ignores whitespace and line changes.

So, if you have a plain text dump like this:

echo "0000 4865 6c6c 6f20 776f 726c 6421 0000" > text_dump

You can convert it to binary with:

xxd -r -p text_dump > binary_dump

And then get useful output with something like:

xxd binary_dump

How to grep a text file which contains some binary data?

You could run the data file through cat -v, e.g

$ cat -v tmp/test.log | grep re
line1 re ^@^M
line3 re^M

which could be then further post-processed to remove the junk; this is most analogous to your query about using tr for the task.

-v simply tells cat to display non-printing characters.