Redirection or pipe inside `find -exec`

Question

Any "find -exec" guru's around.

I have a folder of files I need to send to sendmail (they appear in there when something bad has happened).

• The command

  find . -type f -exec sendmail -t < {} \;
  

  gives me

  -bash: {}: No such file or directory
  

  It doesn't seem to like the <.

• And this

  find . type -f -exec cat {} |sendmail -t \;
  

  gives me

  find: missing argument to `-exec'
  

  It doesn't seem to like the |.

What is wrong?

Answer 1

It looks like you'd like this redirection (<) or pipe (|) to belong to the inside of the -exec … ; statement. This doesn't work because they are handled by your shell before find even runs.

To make them work you need another shell inside -exec … ;. This other shell will handle < or |. Respectively:

find . -type f -exec sh -c 'sendmail -t < "$1"' sh {} \;
find . -type f -exec sh -c 'cat "$1" | sendmail -t' sh {} \;

Note: find . -type f -exec sh -c 'sendmail -t < "{}"' \; is less complicated but wrong. This is explained here: Is it possible to use find -exec sh -c safely?

Answer 2

In both cases your redirection is parsed by the shell, not by find, so you need to escape it:

find . -type f -exec sendmail -f \< {} \;

works as expected.