$ cat file aaa bbb\ccc bbb$ccc $ grep \\\\ file bbb\ccc $ grep '\\' file bbb\ccc $ grep \\$ file bbb$ccc $ grep '\$' file bbb$ccc
$ cat file aaa bbb\ccc bbb$ccc $ grep \\\\ file bbb\ccc $ grep '\\' file bbb\ccc $ grep \\$ file bbb$ccc $ grep '\$' file bbb$ccc