How to compare binary files to check if they are the same?

Question

What is the easiest way (using a graphical tool or command line on Ubuntu Linux) to know if two binary files are the same or not (except for the time stamps)? I do not need

Answer 1

You can use MD5 hash function to check if two files are the same, with this you can not see the differences in a low level, but is a quick way to compare two files.

md5 <filename1>
md5 <filename2>

If both MD5 hashes (the command output) are the same, then, the two files are not different.

Answer 2

Try diff -s

Short answer: run diff with the -s switch.

Long answer: read on below.

---

Here's an example. Let's start by creating two files with random binary contents:

$ dd if=/dev/random bs=1k count=1 of=test1.bin
1+0 records in
1+0 records out
1024 bytes (1,0 kB, 1,0 KiB) copied, 0,0100332 s, 102 kB/s

                                                                                  
$ dd if=/dev/random bs=1k count=1 of=test2.bin
1+0 records in
1+0 records out
1024 bytes (1,0 kB, 1,0 KiB) copied, 0,0102889 s, 99,5 kB/s

Now let's make a copy of the first file:

$ cp test1.bin copyoftest1.bin

Now test1.bin and test2.bin should be different:

$ diff test1.bin test2.bin
Binary files test1.bin and test2.bin differ

... and test1.bin and copyoftest1.bin should be identical:

$ diff test1.bin copyoftest1.bin

But wait! Why is there no output?!?

The answer is: this is by design. There is no output on identical files.

But there are different error codes:

$ diff test1.bin test2.bin
Binary files test1.bin and test2.bin differ

$ echo $?
1


$ diff test1.bin copyoftest1.bin

$ echo $?
0

Now fortunately you don't have to check error codes each and every time because you can just use the -s (or --report-identical-files) switch to make diff be more verbose:

$ diff -s test1.bin copyoftest1.bin
Files test1.bin and copyoftest1.bin are identical

Answer 3

My favourite ones using xxd hex-dumper from the vim package :

1) using vimdiff (part of vim)

#!/bin/bash
FILE1="$1"
FILE2="$2"
vimdiff <( xxd "$FILE1" ) <( xxd "$FILE2" )

2) using diff

#!/bin/bash
FILE1=$1
FILE2=$2
diff -W 140 -y <( xxd $FILE1 ) <( xxd $FILE2 ) | colordiff | less -R -p '  \|  '

Answer 4

Diff with the following options would do a binary comparison to check just if the files are different at all and it'd output if the files are the same as well:

diff -qs {file1} {file2}

If you are comparing two files with the same name in different directories, you can use this form instead:

diff -qs {file1} --to-file={dir2}

OS X El Capitan

Answer 5

Radiff2 is a tool designed to compare binary files, similar to how regular diff compares text files.

Try radiff2 which is a part of radare2 disassembler. For instance, with this command:

radiff2 -x file1.bin file2.bin

You get pretty formatted two columns output where differences are highlighted.

Answer 6

Use cmp command. This will either exit cleanly if they are binary equal, or it will print out where the first difference occurs and exit.