[Sed] Delete one or more lines from a file
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
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