Source code formatting uses a 4 column tab spacing, currently with tabs preserved (i.e. tabs are not expanded to spaces). For emacs, add the following (or something similar) to your ~/.emacs initialization file: ;; check for files with a path containing "postgres" or "pgsql" (setq auto-mode-alist (cons '("\\(postgres\\|pgsql\\).*\\.[ch]\\'" . pgsql-c-mode) auto-mode-alist)) (setq auto-mode-alist (cons '("\\(postgres\\|pgsql\\).*\\.cc\\'" . pgsql-c-mode) auto-mode-alist)) (defun pgsql-c-mode () ;; sets up formatting for Postgres C code (interactive) (c-mode) (setq-default tab-width 4) (c-set-style "bsd") ; set c-basic-offset to 4, plus other stuff (c-set-offset 'case-label '+) ; tweak case indent to match PG custom (setq indent-tabs-mode t)) ; make sure we keep tabs when indenting For vi, your ~/.vimrc or equivalent file should contain the following: set tabstop=4 or equivalently from within vi, try :set ts=4 The text browsing tools more and less can be invoked as more -x4 less -x4