Re: problem using call-process with grep

[Kevin Rodgers]

Drew Adams wrote:
>     When I run grep 'epsilon\($\)' foo
>     from the shell, it finds a match. What does your grep do?
>
> I said:
>
>   And if I run grep from the Cygwin command line (with either
>   parenthetical regexp - single or double backslashes), it
>   works OK. I only have the problem when I use `call-process'.
>
> By command line, I meant shell (bash from Cygwin). (I showed the regexp with
> double-quotes, but single-quotes work too.)
>
> Summary: grep works with that regexp when run from the shell or when using
> the Emacs `grep' command. The only problem is with `call-process'.

The quotes are not part of the regex, and are only necessary when
running the command via a shell (`M-x grep' uses
start-process-shell-command).

The correct way to use call-process would be:

(call-process "grep" nil BUFFER nil "epsilon\\($\\)" "foo")

--
Kevin