Like most operations on any Operating System, there are several ways to do basic file manipulation on Linux. Below are 5 different ways to empty a file.
Redirection is usually used to output command results to a file. However, if we redirect “nothing” to a file, we can overwrite it with a blank file. Redirection can be done using a “>” greater-than symbol or a “|” pipe symbol.
# > file.txt or # :> file.txt
REDIRECT THE echo command
Use the echo command to redirect null values to a file.
# echo -n > file.txt
ndo not output the trailing newline.
UsE THE truncate command
Use the truncate command to shrink or expand the size of a file to the size specified by the
s option value. Use zero to make the file empty.
# truncate -s 0 file.txt or # truncate file.txt --size 0
REDIRECT THE /dev/null device
The null device is usually used for disposing of unwanted output streams of a process or as a empty file for input streams or a redirection operation.
# cat /dev/null > file.txt or # cp /dev/null file.txt cp: overwrite 'file.txt'? y
SCRIPT THE Vim Editor
Vim is a text editor built to make creating and changing any kind of text very efficient. It is included as “vi” in most Linux/Unix systems.
# ex -sc ':%d|x' file.txt or # ex -sc ':1,$d|x' file.txt
ex: Enter into Ex mode
s: Silent; do not display prompts
c: Run the given ex command upon startup
:: Invoke an ex command
%: Choose all the lines
d: Delete selected lines
x: save and close
2g.txt: input filename