Simple function to find files in a project from a manually specified list of projects

find-in-project.el

;; a list of root directories for projects. used for find-greping. Put
;; your root directories here. No need to start at root
(setq my-project-list '("/partial/path/to/directory"
                        "/another/directory/path"
                        "/one_more_path/"))

(defun match-list (string list)
  "returns the entry in list which contains the string"
  (when list
    (let ((matchIndex (string-match (car list) string)))
      (if matchIndex
          (substring string 0 (+ matchIndex (length (car list))))
        (match-list string (cdr list))))))

(defun get-root-dir ()
  "attempts to find the root directory of the current project, based on a list of projects above"
  (let ((filename (buffer-file-name)))
        (if filename
            (match-list filename my-project-list)
          (message "no file in buffer!"))))
     
(defun find-in-project-helper (bounds)
  (when bounds
    (let ((rootDir (get-root-dir))
          (needle (buffer-substring (car bounds) (cdr bounds))))
      (when rootDir
        ;; don't find files that are binary or end in '~'
        (find-grep (format "find '%s' -type f -and -not -name '*~' -exec grep -InH -e '%s' {} +" rootDir needle))))))
 
(defun find-in-project ()
  "finds region or current word in point"
  (interactive)
  (if (use-region-p)
      (find-in-project-helper (cons (region-beginning) (region-end)))
    (find-in-project-helper (bounds-of-thing-at-point 'word))))