grep returns "Binary file (standard input) matches" when trying to find a string pattern in file

Question

I'm on Ubuntu and I typed cat .bash_history | grep git and it returned

Binary file (standard input) matches

My bash_history does exist and there are many lines in it that starts with git.

What caused it to display this error and how can I fix it?

Whats the output of file .bash_history (file ~/.bash_history)? — heemayl, Jan 08 '17 at 05:07
for some reason this was just happening with my apache logs. thanks for the q&a — Eaten by a Grue, Apr 24 '18 at 01:07
very closely related: https://unix.stackexchange.com/q/19907/5510 — Trevor Boyd Smith, Feb 08 '19 at 21:01

score 363 · Answer 1 · edited Dec 26 '19 at 17:22

363

You can use grep -a 'pattern'.

from man grep page:

-a, --text
Process a binary file as if it were text; this is equivalent to the --binary-files=text option.

edited Dec 26 '19 at 17:22

Pablo A

2,712

answered Jul 20 '17 at 14:05

AK_

3,782

This has helped me when using the -z flag to match across several lines. – stragu Apr 24 '18 at 07:51
2

It has worked for me, but still weird because my file isn't a binary file. [grid@serverdg2 trace]$ file listener.log listener.log: data – Astora Dec 01 '20 at 03:42
1

It is enough, if your file has a single non-decodable character, and grep will fail (if not used with -a) – ivan May 05 '22 at 11:43

score 28 · Accepted Answer · edited Nov 08 '19 at 15:01

28

Presumably the file .bash_history starts with non-text data, hence grep is treating the file as binary. This is confirmed by the file .bash_history output:

.bash_history: data

You can read a few bytes from start to have a conforming view:

head -c1K .bash_history

Here I am reading first 1 KiB.

You can pipe the STDOUT to hexdump/od or similar.

As a side note, grep takes filename(s) as argument, so cat is useless here; try this:

grep git .bash_history

edited Nov 08 '19 at 15:01

Kevdog777

3,224

answered Jan 08 '17 at 05:15

heemayl

56,300

1

I'm still not sure how to solve the grep issue, head -c1k .bash_history read the first 38 lines of my .bash_history file. Everything was readable – answerSeeker Jan 08 '17 at 05:22
6

@TatakaiWasumi Whats the output of grep -a git .bash_history? – heemayl Jan 08 '17 at 05:29
2

That worked! I got everything I wanted from it. What does -a do? – answerSeeker Jan 08 '17 at 05:31
10

@TatakaiWasumi -a makes grep to treat the file as binary. – heemayl Jan 08 '17 at 05:34
that's weird, is there a way to convert my bash history back to a text file if grep thinks it's binary? – answerSeeker Jan 08 '17 at 05:35
@TatakaiWasumi can you go through the file and check for any unusual string? – heemayl Jan 08 '17 at 05:38
9

-a make grep process a binary file as if it were text. – lashgar Apr 06 '18 at 23:01
file claims it's data yet...I don't see it: $ head -c1K .bash_history |xxd 00000000: 7375 646f 2061 7074 2075 7064 6174 650a sudo apt update. – Mark Jeronimus May 04 '22 at 14:25

Brad Nelson · Answer 3 · 2020-12-15T23:11:48.643

11

This can be caused by null bytes in your bash history. Removing lines with null characters may resolve the issue. You can check for them using grep's Perl-regexp mode:

grep -Pa '\x00' .bash_history

This post has suggestions for non-unix systems.

edited Dec 15 '20 at 23:11

answered Dec 15 '20 at 23:06

Brad Nelson

111

1

This actually helped me find out why I was having the same problem. – DUO Labs Sep 23 '21 at 19:16
Plus one from me too. – L1ttl3J1m Mar 31 '22 at 00:43
same as me, too – Cherrymelon Oct 10 '23 at 02:15

score 5 · Answer 4 · edited Aug 09 '20 at 00:32

I had the same problem when I want to grep my .bash_history. (Little Note: I renamed my history, so that a new one was created. This new history was not treated as a binary.)

In @heemayls answer it is stated, that grep takes filenames and cat would be useless. This is not entirely true. From greps man page:

If no files are specified, or if the file “-” is given, grep searches standard input.

So you could use cat and pipe it to grep. However this solves not the problem that .bash_history is treated as a binary. The only right thing is to use grep -a (Like in the answer from @AK_) whether you grep the history directly or with cat and a pipe.

cat .bash_history | grep -a git

or

grep -a git .bash_history

Gajraj Singh Chouhan · Answer 5 · 2020-08-29T12:04:15.583

4

Error is due to the data in the file being binary, you can use strings command to see the human readable (i.e. strings) part which you would normally search using grep

strings data | grep -i whatever

edited Aug 29 '20 at 12:04

answered Mar 24 '20 at 08:57

Gajraj Singh Chouhan

179

1

This does not address the first part of the question, i.e. "what causes the issue". – Kusalananda Mar 24 '20 at 09:47

grep returns "Binary file (standard input) matches" when trying to find a string pattern in file

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