problem getting this simple regex to match in grep

Question

I have answered my own question in its prior revision, no need to refer to it, but it leads to another strongly related matching problem, so i've revised this question to matching something very similar, but running into a problem.

I want to match quote, 2, space, any char that is not a literal dot.

This is using gnuwin32's grep. Not cygwin's grep.

C:\>echo "2 008abc.html" | grep -oiP \"2 [^.]
grep: [^.]': No such file or directory

C:\>echo "2 008abc.html" | grep -oiP ^"2 [^.]

C:\>echo "2 008abc.html" | grep -oiP """2 [^.]
grep: [^.]: No such file or directory

C:\>echo "2 008abc.html" | grep -oiP """2 0
grep: 0: No such file or directory

C:\>echo "2 008abc.html" | grep -oiP """"2 0"
"2 0


C:\>echo "2 008abc.html" | grep -oiP """"2 [^.]"

C:\>echo "2 008abc.html" | grep -oiP """"2 0"
"2 0

Answer 1

It looks like you're using Windows Command Prompt (cmd.exe) as your shell, and you're getting tripped up by its quoting conventions, or lack thereof. If I run your command in Fedora 15 bash shell, it works. If I run it in Windows using cygwin bash shell, it works.

To get it to work with cmd.exe, you have to change the quotes and spacing. I ran the commands below in cmd.exe on Windows 7. Note how I changed the quotes on the grep command to use single quotes instead of double quotes, and there is no space before the pipe (|).

I am using the cygwin version of GNU grep, which should behave the same as your win32 GNU grep.

c:\>c:\cygwin\bin\grep --v
GNU grep 2.6.3

Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

c:\>echo "2008abc.html"| c:\cygwin\bin\grep -oiP '\"[^.]'
"2

If there is a space before the pipe, the space will be echoed through the pipeline and grep will match it. This is due to the idiotic parsing behavior of cmd.exe.

c:\>echo "2008abc.html" | c:\cygwin\bin\grep -oiP '\"[^.]'
"2
"

For your own sanity, see if you can use cygwin bash or any other shell with reasonable and consistent quoting conventions.

Answer 2

This is a solution.

C:\>echo "2 008abc.html" | grep -oiP \"2" "[^.]
"2 0

This experimentation helped (w is w.exe, which is w.c compiled)

C:\>w \"2\ [^.]
argv[0] = w
argv[1] = "2\
argv[2] = [^.]

C:\>w \"2" "[^.]
argv[0] = w
argv[1] = "2 [^.]

C:\>

Here is another solution

C:\>echo "2 008abc.html" | grep -oiP "\"2 [^^.]"
"2 0

which as you can see I found after a little fiddling, though found pretty quickly

W:\other>w "\"2 [^.]"
argv[0] = w
argv[1] = "2 [.]

W:\other>w "\"2 [\^.]"
argv[0] = w
argv[1] = "2 [\.]

W:\other>w "\"2 [^.]"
argv[0] = w
argv[1] = "2 [.]

W:\other>w "\"2 [^^.]"
argv[0] = w
argv[1] = "2 [^.]

w.c

#include <stdio.h>

int main(int argc, char *argv[]) {
    int i = 0;
    while (argv[i]) {
        printf("argv[%d] = %s\n", i, argv[i]);
        i++;
    }
    return 0;
}