CODEWITHSUNDEEP
emacs
msampaio
msampaio

Reputation: 3433

Removing lines with specific words

I have a text file with multiple lines such as:

amanda: foo
robert: bla
amanda: bar
peter: da

I'd like to remove all lines with amanda. I use ctrl-s and kill each line individually. Is possible to remove all lines at once?

Upvotes: 2

Views: 603

Answers (3)

Mirzhan Irkegulov
Mirzhan Irkegulov

Reputation: 18055

Although @Marcos's answer is idiomatic one (you should use it), let's explore other variants. Let's say you have a text buffer and you want to delete a line containing li in it:

Vladimir
Ilich
Ulyanov

Remember, that ^ matches beginning of line and $ end of line in regex. $ doesn't touch the newline character after the line, so replace with regex ^.*li.*$ will produce an empty line, as per @ataylor's answer:

Vladimir

Ulyanov

For some reason it's impossible to match before ^ and after $ in regex, therefore \s-^.*li.*$ nor ^.*li.*$\s- won't work. Note, \s- matches any whitespace character, (i.e. space, tab, newline and carriage return), so intuitively the regexes should've deleted the newline too, as newline is the only possible whitespace character before ^ or after $. To match exactly newline, you should enter it verbatim, C-q C-j by default. Emacs frequently denotes the newline in separate font color as ^J, it's not a sequence of ^ and J, but a single character, please pay attention.

Therefore to delete a line containing li, you could run command query-replace-regexp on string ^.*li.*^J, where ^J is newline:

Vladimir
Ulyanov

Upvotes: 1

ataylor
ataylor

Reputation: 66069

One way is to use query-replace-regexp with a regular expression of ^.*amanda.*$ to an empty string.

Upvotes: 1

msampaio
msampaio

Reputation: 3433

M-x delete-matching-lines. It's possible to use regular expression.

Upvotes: 6

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