My dumb question of the day: What does the tilda key do in tcsh

Phishfry

Phishfry

Every once in a while I accidentally hit the tilda key(~) and I get the following output under the root user:
Code: 
/root: Permission denied.

I looked through /.cshrc and I did not see an alias for the tilda.
What does it do in the tcsh shell?
 
It translates to your home directory, and that by itself can't be "executed", hence the "permission denied"? Same as if you'd type "/root".
 
The ~ is just a short-hand for $HOME. This also works; cd ~myuser which is translated to cd /usr/home/myuser (or where myuser's home directory has been set to). Quite useful, I use it a lot.

Code: 
       The character `~' at the beginning of a filename refers to home
       directories.  Standing alone, i.e., `~', it expands to the invoker's
       home directory as reflected in the value of the home shell variable.
       When followed by a name consisting of letters, digits and `-'
       characters the shell searches for a user with that name and substitutes
       their home directory; thus `~ken' might expand to `/usr/ken' and
       `~ken/chmach' to `/usr/ken/chmach'.  If the character `~' is followed
       by a character other than a letter or `/' or appears elsewhere than at
       the beginning of a word, it is left undisturbed.  A command like
       `setenv MANPATH /usr/man:/usr/local/man:~/lib/man' does not, therefore,
       do home directory substitution as one might hope.

It's not limited to the C shells though, it works with Bourne shells too.
 
You must log in or register to reply here.
Back
Top