grep output redirected to file produces binary file

Question

I have a file foo with the content:

foo

Then I perform:

grep "foo" foo > bar

produces a bar "binary" (according to the file browser) file, with the content

[01;31m[Kfoo[m[K

If I try the same with awk

awk '{ print 1ドル }' foo > bar

produces a normal text file with the content

foo

I feel I'm missing something obvious here, is this normal? Why the discrepancy between the (at least) two commands.

• Arkadiusz Drabczyk: I cannot reproduce with echo foo > foo; grep "foo" foo > bar; file bar
• schrodingerscatcuriosity: I should've follow the clue of the color pattern characters.

Answer 1

The problem was simple. I had an alias of grep in my bashrc with the --color=always flag:

alias grep="grep --color=always"

The solution was just to unalias the command

unalias grep

and delete the alias from the .bashrc, then source it . .bashrc.