4

Say I am in dired and the pointer is on a file called test which contains:

1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
11. 
12. 
13. 
14. 
15. 
16. 
17. 
18. 
19. 
20. 

I type ! to run a shell command on this file. I type tac | head -n 2

I get :

1.
2.

But I expected:

20.
19.

As if I has run tac test | head -n 2 in the shell.

What am I misunderstanding and what is the correct way to get the behaviour I wish?

5

By default, dired-do-shell-command inserts the file name at the end of the command you enter. In effect, you are doing this:

tac | head -n 2 test

Without an argument, tac doesn't produce any output for your pipe, so head returns the first two lines of test and then you're done.

You can use the ? symbol to tell dired to put your filename at that location in the command. i.e.,

tac ? | head -n 2
  • 2
    The docstring of dired-do-shell-command explains how to interpolate the relevant file name into the resulting command. – Basil Aug 15 '18 at 14:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.