How to empty or delete a large file in Linux

When dealing with files in Linux , sometimes you need to empty it without opening the actual file . Also , this is very useful is safely emptying a dynamically writing file, especially some of the log files . So we are looking on some of the commands to do this .

Empty using echo command, say we are emptying the access.log

echo "" > access.log

echo > access.log

So the normal echo commands with redirect output will leave an empty line at the end . To send a null output , use -n flag which tells echo to not output the trailing newline that leads to the empty line produced in the previous command.

echo -n "" > access.log

Empty using dd , cat and cp commands

dd if=/dev/null of=access.log

 cat /dev/null > access.log

cp /dev/null access.log