find命令末尾的\\;和+之间有什么区别？

Question

These are bash commands that are used to convert tabs to spaces. Here's the link to the original stackoverflow post.

This one uses \\; at the end of the command

find /path/to/directory -type f -iname '*.js' -exec sed -ie 's|\t|    |g' '{}' \;

This one uses + instead of \\; .

find /path/to/directory -type f -iname '*.js' -exec sed -ie 's|\t|    |g' '{}' '+'

What exactly is the difference between the two?

Answer 1

The \\; or + is not related to bash. It's an argument to the find command, specifically to find 's -exec option.

find -exec uses {} to pass the current file name to the specified command, and \\; to mark the end of the the command's arguments. The \\ is needed because ; by itself is special to bash; by typing \\; , you can pass a literal ; character as an argument. (You can also type ';' or ";" .)

The + symbol (no \\ needed because + is not special to bash) causes find to invoke the specified command with multiple arguments rather than just once, in a manner similar to xargs .

For example, suppose the current directory contains 2 files named abc and xyz . If you type:

find . -type f -exec echo {} \;

it invokes the echo command twice, producing this output:

./abc
./xyz

If you instead type:

find . -type f -exec echo {} +

then find invokes echo just once, with the following output:

./xyz ./abc

For more information, type info find or man find (if the documentation is installed on your system), or you can read the manual online at http://www.gnu.org/software/findutils/manual/html_node/find_html/