Sed delete all the words before a match

sedtext processing

I want to delete all the words before a pattern for example: I want to delete all the words before STAC.

Input:

asd
asdd
asddd
STAC
asd
as

Output:

STAC
asd
as

I have this code sed -ni "s/^.*STAC//d" myfile

Best Answer

sed works linewise, that's why your try will not work.

So how to do it with sed? Define an address range, starting from the STAC line (/^STAC$/) to the end of the file ($). Those should be printed, so everything else (!) should get deleted:

sed -i '/^STAC$/,$!d' myfile

Related Solutions

How to delete all occurrences of a list of words from a text file

For your actual use case I recommend terdon's answer using Perl.

However, the simple version, without handling words that are substrings of other words (e.g. removing "king" from "hiking"), is to use one Sed command to generate the command run by a different Sed instance on your actual file.

In this case, with wordfile containing "king" and "queen" and textfile containing your text:

sed -e "$(sed 's:.*:s/&//ig:' wordfile)" textfile

Note that the "ignore case" flag is a GNU extension, not standard.

SED – Delete All Lines Before Matching One, Including This One

Similar to your "clean solution":

sed -e '1,/HI_THERE/d' input_file

The first line in the file is line 1 - there's no special ^ address because you always know that, while $ is needed for the end because you don't (necessarily) know which line that is.

This does fall over if the matching line is the first line of the file. With GNU sed you can use 0 instead of 1 to deal with that. For POSIX sed and for portability (which seem to be different in this case) it's more complex (see comments below and this follow-up question).

Best Answer

Related Solutions

How to delete all occurrences of a list of words from a text file

SED – Delete All Lines Before Matching One, Including This One

Related Question