There are 3 different ways of grepping in emacs:
grep
lgrep (local grep - will only search the directory you're currently in)
rgrep (recursive grep - will search subdirectories)
Installing cygwin seemed to grant access to 2 types of grep: grep and lgrep. While rgrep continued to spout "Parameter format not correct" messages.
> rgrep -nH "meta" *.*
find . "(" -path "*/CVS" -o -path "*/.svn" -o -path "*/{arch}" -o -path "*/.hg" -o -path "*/_darcs" -o -path "*/.git" -o -path "*/.bzr" ")" -prune -o -type f "(" -iname "*.*" ")" -exec grep -i -nH -e "meta" {} /dev/null ";"
FIND: Parameter format not correct
Grep exited abnormally with code 2 at Sun Feb 06 23:12:00
It turns out that lgrep utilizes only the normal grep formatting. However, it appears that rgrep pipes its arguments to "find" in order to build the subdirectory tree where it runs grep on each folder individually. However emacs utilizes windows find by default and must be pointed to cygwin's find instead in order for rgrep's unix style arguments to work.
Please add the following line to your .emacs:
(setq find-program "C:\\path-to-cygwin\\bin\\find.exe")
*NOTE* You need to fully exit emacs and restart instead of merely running load-file ~/.emacs in order to overwrite many of the cached cygwin interfaces.
At this point rgrep sort of works. When running the same above search query I started receiving the following output (note how we are now running cygwin's find method:
> rgrep -nH "meta" *.*
C:\cygwin\bin\find.exe . "(" -path "*/CVS" -o -path "*/.svn" -o -path "*/{arch}" -o -path "*/.hg" -o -path "*/_darcs" -o -path "*/.git" -o -path "*/.bzr" ")" -prune -o -type f "(" -iname "*.*" ")" -exec grep -i -nH -e "meta" {} NUL ";"
/usr/bin/find: `grep': No such file or directory
/usr/bin/find: `grep': No such file or directory
/usr/bin/find: `grep': No such file or directory
.
.
.
etc
Emitting a "/usr/bin/find: `grep': No such file or directory" error for each unsuccessful search attempt.
After much searching I found a workaround here detailing how to pipe the warning message to "/dev/null" instead of "windows-null" in order to suppress the warning messages found in the grep output buffer.
Please add the following to your .emacs file:
;; Prevent issues with the Windows null device (NUL)
;; when using cygwin find with rgrep.
(defadvice grep-compute-defaults (around grep-compute-defaults-advice-null-device)
"Use cygwin's /dev/null as the null-device."
(let ((null-device "/dev/null"))
ad-do-it))
(ad-activate 'grep-compute-defaults)
This fixed rgrep for me. Nothing I seemed to do has gotten grep -r working however, and it still continues to only search the current directory. Supposedly installing ack will make all these problems go away but I haven't gotten it working quite yet. Hope this helps.
