(more) Using sed to delete lines from file

[Sed] Delete one or more lines from a file
Here is how to remove one or more lines from a file. 
sed '{[/]||[/]}d'       
sed '{[/][,][/]d' 
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 
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