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Comment by codejoust | Hacker News Reader

Something else really useful: mkdir stuff cd !$

!$ takes the last argument from the previous command, instead of the whole thing.

chmod 664 site/* - changes the permissions for all the files in the site directory. * is a wildcard in bash for specifying directories.

Another useful feature of bash is brace expansion: mv site{,-old} => mv site site-old The brace expansion expands the argument with the values in a comma separated list: college pic_00{1,4,3}.jpeg college.jpeg yields pic_001 pic_004, pic_003

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* is a wildcard for everything in the directory including files and directories. so the chmod will remove the execute permission from directories also.

* will not match hidden files:

  > ls -a tmp
    file1
    file2
    .file3
  > ls tmp/*
    file1
    file2
  > ls tmp/.*
    .file3

<ALT>-. does the same thing except it prints it before you hit enter.

or <ESC>-. if you recently got a macbook and can't figure out how to remap the silly keyboard defaults and make alt work properly in a terminal..

I have a function for it which is quite useful: mcd () { mkdir "$@" cd "$@" }

Just run mcd foobar and you (try) to create the directory and enter it. IMO a nice shortcut.

You know that mkdir can take multiple directories? If you run:

  mcd dir1 dir2 dir3

That function will run:

  mkdir "dir1" "dir2" "dir3" cd "dir1" "dir2" "dir3"

(Surrounding $@ with double quotes, puts quotes around each item instead of quotes around the whole string:

  command "directory1/sub directory" "directory2"

    $@ => directory1/sub directory directory2
  "$@" => "directory1/sub directory" "directory2"
  "$*" => "directory1/sub directory directory2"

)

* is a wildcard in general. Its behavior is identical to the .* in a regular expression.

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