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Navegación eficiente de la CLI
La CLI (Interfaz de línea de comandos) es un entorno muy potente, flexible y programable. Si utiliza la interfaz de línea de comandos de forma regular, sabrá lo importante que es personalizar su entorno de trabajo y desarrollar accesos directos para garantizar un flujo de trabajo eficiente. A continuación hay algunos consejos sobre cómo navegar a través de directorios de una manera rápida y fácil.
Go Back Home
The cd
command changes the current working directory to your /home
:
$ pwd /home/user/data/documents/work $ cd $ pwd /home/user
Go Back to the Previous Directory
To go back to the previous directory, you can use cd -
:
$ pwd /home/user/.i3/config $ cd ~/data/projects/dotfiles/i3 $ pwd /home/user/data/projects/dotfiles/i3 $ cd - /home/user/.i3/config $ pwd /home/user/.i3/config
Use the Last Argument of the Previous Command
The $_
variable returns the last argument of the previous command. This can be helpful in a variety of scenarios:
$ pwd /home/user/downloads/ $ cp i3status.tar.gz ~/data/builds/i3/i3status $ cd $_ $ pwd /home/user/data/builds/i3/i3status
$ chmod +x /path/to/my/script/script.sh $ $_ (This will execute script.sh)
The same can be achieved using the combination Alt+. or Esc+..
Bash Completion
Bash offers TAB completion, a very useful feature that reduces the number of keystrokes you are required to type to navigate to a directory.
$ cd d[TAB]
It will expand the path with a directory starting with d
. Please note that Linux is case-sensitive so ~/Desktop
or ~/Downloads
will be ignored. If there are more than 1 directory starting with d
, you need to press the TAB twice to get the possible completions listed below:
$ cd d[TAB][TAB] data/ downloads/
Now press o and TAB to expand the path to downloads
.
It can greatly reduce the number of keystrokes when accessing directories. For example:
$ cd data/projects/python-dir/euler/completed/
The keystrokes I used:
cd da[TAB]p[TAB]p[TAB]e[TAB]c[TAB]
If each directory contained only one subdirectory, I could have done the following:
cd [TAB][TAB][TAB][TAB][TAB]
Not only does the bash completion reduce the number of key strokes, but it also comes handy if you do not remember directory names.
Please note that bash completion works also on files:
$ cp data/projects/scripts/sync-script.sh .
Keystrokes used:
$ cp d[TAB]p[TAB]s[TAB]s[TAB] .
The dot (.) represents the current directory so the command will copy sync-script.sh
to the current directory.
Programmable Bash Completion
To take advantage of all Bash completion features, you need to install an additional package from /extra
:
# slackpkg install bash-completion
CDPATH
If you work in certain directories on a regular basis, you might want to include them in the $CDPATH variable. Suppose you often work in the slackbuilds
directory which contains some builds:
$ cd ~/data/projects/slackbuilds/ $ ls i3 i3status yajl dmenu libev
Add it to the $CDPATH
variable by modifying ~/.bashrc
:
CDPATH=$CDPATH:~/data/projects/slackbuilds/
Please note the path included in the CDPATH variable is the path to the parent directory where the said directories are located.
After you have sourced .bashrc
(source ~/.bashrc
), you can cd
to any of those directories from any place:
$ pwd /home/user/.config/xfce4 $ cd yajl /home/user/data/projects/slackbuilds/yajl
If you would like to enable Tab completion within the directories added through the CDPATH variable, you need to install bash-completion
from Slackware's /extra
directory.
usr
, etc
, which can result in unpredictable behaviour.
Symlinks
In some situations you may consider using symlinks to create shortcuts to regularly visited directories:
$ ln -s /home/user/data/projects/scripts/slackbuilds ./slackbuilds
Bash Aliases
You can make your life easier by creating aliases (= shortcuts) for commands that you use often. The syntax is very simple:
name_of_the_alias='value'
You can place your aliases in ~/.bashrc
. You might need to create this file. Each time you edit this file you need to source
it afterwards for the changes to take effect:
source ~/.bashrc
or
. ~/.bashrc
When it comes to navigation, one could, for example, create a few aliases to speed up navigating up the directory tree:
alias 1.='cd .. ; pwd' alias 2.='cd ../.. ; pwd' alias 3.='cd ../../.. ; pwd' alias 4.='cd ../../../.. ; pwd'
The value of an alias can be quite complex. As you can see, 4.
will first change directories cd ../../../..
and then print the current working directory - pwd
. Please note a semi-colon (;
) separating the commands.
$ cd data/projects/python-dir/euler/ $ 4. /home/user $ cd - /home/user/data/projects/python-dir/euler $ 3. /home/user/data
Aliases can be used in a number of different ways. A few more examples:
alias epyt='emacs -nw /home/user/data/projects/python-dir/euler/32-problem.py' alias slacktop='ssh user@slacktop'
Directory Stack
BASH features some helpful directory stack buildins that help you navigate recently visited directories.
pushd
- push a directory into the directory stack andcd
to it.popd
- remove a directory from the directory stack andcd
to it.dirs
- display the list of the directories in the stack.
How does it work in practice?
First of all, add a directory to the stack. Please note that it also automatically switches to the directory (the -n
flag suppresses this behaviour).
user@darkstar:~$ pushd data/projects/programming/ ~/data/projects/programming ~ user@darkstar:~/data/projects/programming$
Alternatively, you can cd
to a given directory and issue:
pushd .
After adding a few directories you can display the content of the stack:
user@darkstar:~$ dirs -v 0 ~/projects/web-develop/project-eden/includes 1 ~/projects/web-develop/project-eden/includes 2 ~/projects/web-develop/project-eden/pages/en 3 ~/projects/web-develop/project-eden/css 4 ~/projects/designs 5 ~/projects/notes 6 ~/public_html/project_eden
Please note that the first entry always displays the current working directory so if it also sits at the top of the stack, you'll see what seems like duplicate lines. The -v
flag is responsible for a nicely indexed output.
To switch to one of the directories in the stack you could issue:
user@darkstar:~$ cd $(dirs +2 -l) user@darkstar:~/projects/web-develop/project-eden/pages/en$
Admittedly, this is not the most concise way of changing directories. To make it shorter we can add an alias and a function to the ~/.bashrc
file.
alias dv='dirs -v'
List the current stack by simply typing dv
.
cdd() { position=$1 if [ -z $position ]; then echo "You need to specify the position of the directory in the stack" else cd $(dirs +$1 -l) fi }
The cdd
function1) makes it possible to cd
to a given directory from the stack by typing:
cdd 3