Question

I use command of find, for example:

find . -name "*.log" -exec grep "running" {} \;

why the command of find need {} , a blank and \?

Answer 1

This is because of the -exec parameter: the {} is a placeholder for the file that will be passed to the command.

the semicolon (;) tells find that the -exec argument list is over, but since ; is also a shell operator, you need to escape it so that it reaches find: \;

-exec works like this: for every file that is found, the first argument after -exec (the command) is executed and all parameters up until the ; are passed as arguments to the command. The {} is then replaced by the current filename that is found by find.