Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
there is one line in file data, as
[overall], ….
when using grep to obtain this line, I find this can be done only by
grep “\[overall]” data
just out of curiosity, Why does it need to escape [ while not for ].
EDIT: this is tested on ubuntu 12.04
Because the
]only has any special meaning when it has already been preceded by a[that was not escaped.You can have fun (if you’ve got the right, somewhat distorted, mindset) with:
This searches for
],[or-. You have to be careful with the placement of]; it must go at the start of the character class. You have to be careful with the placement of-; it must go at the start or end of the class. And the caret that negates a class must go first.