Simple unix command, what is the {} and \; for

Question

With this set of commands, what are the {} and \; characters for?

find . -name '*.clj' -exec grep -r resources {} \;

Answer 1

See man find. (particular the part about -exec)

When using -exec to run a command on each of the files found, the {} is replaced with the name of each file found, and the command is terminated by \;

In your example, all files found under the current directory (.), matching the name *.clj will have the command grep -r resources run on them (to find the string resources if it exists in each of those files).

It's actually somewhat redundant, since -r is for recursively searching subdirectories, and that's what find is already doing.

Answer 2

In find, the -exec parameter grabs the rest of the parameters up til the ; (semicolon) which has to be escaped, hence the \;. Within this span, {} is replaced with the filename being inspected.

Answer 3

The character string "{}" will be replaced by the current file being processed. The escaped semi-colon terminates the command argument for the -exec option.

Answer 4

Consider this alternative command which I find easier to understand:

find . -name *.clj | xargs grep -r resources