8.3 Introduction to tcsh

Article 8.2 introduces bash and talks about shells that came before it. A lot of shell users prefer tcsh. It's like the C shell, but tcsh has added plenty of useful features and also fixed some notorious C shell bugs (47.2). In fact, tcsh is so much like csh (except for those ugly bugs) that when we say "the C shell" or csh in this book, we're also talking about tcsh.

In general, tcsh has a lot of the same features as bash. So I won't repeat the list from article 8.2. Instead, here are a few differences (from the point of view of a casual tcsh user like me, that is).

• My favorite tcsh feature confirms a command like the one below. I meant to type rm *.c:

  % rm * .c
  Do you really want to delete all files? [n/y] n

  In my opinion, tcsh keeps a better watch over the command line than bash does.

• My dyslexic fingers also like the automatic command name correction. In the next example, I type srot. Instead of saying Command not found, tcsh asks if I meant sort:

  % who | srot +3n +4
  
  CORRECT>who | sort +3n +4 (y|n|e|a)? y
  kim            pts/0        Jul 27 14:40  (rock.ny.ora.com)
  jpeek          pts/1        Jul 28 08:09  (jpeek.com)
      ...

• Like csh, tcsh has arrays (47.5). I find these really useful, both interactively and in shell programs. (bash won't have them until version 2.0.)

• On the downside, the shell variables - including prompts, and their setting - seem less flexible in tcsh. For example, resetting the prompt (except nice built-ins like %c2, which gives the last two parts of the current directory path) requires setting aliases.