XEmacs Tips for Programmers

1. XEmacs Tips for Programmers A lunchtime seminar

2. XEmacs Background • XEmacs not Emacs on Linux hosts • XEmacs is a specialized LISP interpreter • Built-in knowledge of fonts, files, buffers, etc. • ‘Infinitely’ customizable • Lots of packages/tools available • Thousands of “levers and knobs” to play with • With its great flexibility, it can also be intimidating • Options and Customize pulldown menus can help

3. XEmacs Tips for Programmers • More help at your finger tips • Under Help pulldown menu • Info • FAQ • Tutorial • init.el example • Look at other users’ init.el files. • www.xemacs.org • Newsgroups on Usenet • comp.emacs.xemacs • comp.emacs

4. XEmacs Tips for Programmers • Many packages and tools for programmers exist that are bundled with XEmacs • Compare or merge files and directories • Access to CM tools like RCS, SCCS, CVS • Compilation mode • Search utilities like grep, etags and fume • Can even run GNU debugger within XEmacs • Language modes

5. XEmacs Tips for Programmers • Compare tool called “Ediff” • Based on UNIX diff command • Allows user to easily compare and merge files and even entire directories

6. XEmacs Tips for Programmers • I find that the Ediff toolbar GUI is helpful • Options->Customize->Emacs->Programming->Tools->Ediff (setq ediff-use-toolbar-p t)

7. XEmacs Tips for Programmers • Configuration Management • None for PVCS  • My attempt to do so resulted in pscmd • XEmacs ‘knows’ about CVS, RCS and SCCS • Checking in and out code is very easy. • CVS: not so familiar with it, but willing to help

8. XEmacs Tips for Programmers • Compilation can be done locally • Environment inherited from parent • Can run a pre-compilation 'hook' • Remote compilation is very cool, IMHO • A bit more effort to set up • By default, ‘rsh’ commands are used – no good here at MDL. • Override 'hook' allows XEmacs to use ssh instead • Directory trees on local and remote host have to look the same. (?)

9. XEmacs Tips for Programmers • In compilation mode, XEmacs can parse output from compiler to locate the problem(s) in your code. • Anyone using this functionality on IBM? (setq compilation-error-regexp-systems-list (quote (qnu comma)) compilation-mouse-motion-initiate-parsing nil compilation-ask-about-save t compile-command “gmake “)

10. XEmacs Tips for Programmers Etags and Fume packages What the heck are those? They help programmers find routines quickly Fume lists routines within files Etags finds routines distributed among files and directories GNU Global is a new package for function searches Haven't tried it, looks promising. www.gnu.org/software/global/global.html

11. XEmacs Tips for Programmers To enable FUnction MEnu (FUME) For Emacs TAGs (etags), it’s ready for use by default You need to run etags command first though (require ‘function-menu) (add-hook ‘find-file-hooks ‘fume-add-menubar-entry)

12. XEmacs Tips for Programmers • Language sensitive editing • Formatting styles available for many programming languages • C, Python, Java, LISP & FORTRAN • Available styles for “C” like languages • GNU, K&R, BSD, Stroustrup, Whitesmith,Ellemtel • Can even create your own! But . . . . • Ellemtel style matches MDL standard, so use that • MDL FORTRAN programming style is F77 and XEmacs uses that by default.

13. XEmacs Tips for programmers • To set programming style for C languages • See ~oberfiel/.xemacs/customize-programming.el for more info. (setq c-set-style “ellemtel”)

14. XEmacs Tips for Programmers • EFS and TRAMP packages • Allows users to view/edit remote files as if they were local. • EFS uses ftp • A problem at MDL: intranet ftp is disabled • TRAMP uses ssh • Useful between MDL and NCEP IBM? • Using TRAMP and remote compilation package could speed up the development process?

15. XEmacs Tips for Programmers • Both EFS and TRAMP are triggered by special find-file name syntax • EFS • Tramp • For tramp to work • Use SSH to access remote machine w/o password /username@machine:/tmp/foo.txt /[username@machine]/tmp/foo.txt