Here is how to remove one or more lines from a file.

Syntax:

sed ‘{[/]||[/]}d’

sed ‘{[/][,][/]d’

/…/=delimiters
n = line number

string = string found in in line

regex = regular expression corresponding to the searched pattern

addr = address of a line (number or pattern )

d = delete

Examples

Remove the 3rd line:

sed ‘3d’ fileName.txt

Remove the line containing the string “awk”:

sed ‘/awk/d’ filename.txt

Remove the last line:

sed ‘$d’ filename.txt

Remove all empty lines:

sed ‘/^$/d’ filename.txt

sed ‘/./!d’ filename.txt

Remove the line matching by a regular expression (by eliminating one containing digital characters, at least 1 digit, located at the end of the line):

sed ‘/[0-9/][0-9]*$/d’ filename.txt

Remove the interval between lines 7 and 9:

sed ‘7,9d’ filename.txt

The same operation as above but replacing the address with parameters:

sed ‘/-Start/,/-End/d’ filename.txt

The above examples are only changed at the display of the file (stdout1= screen).

For permanent changes to the old versions (<4) use a temporary file for GNU sed using the “-i[suffix]”:

sed -i”.bak” ‘3d’ filename.txt

via

Sed – Delete one or more lines from a file.

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