Navigating Paths
The pwd command displays the full path name of the current location, which helps determine appropriate syntax for reaching files using relative path names. The ls command lists directory contents for the specified directory or, if no directory is given, for the current directory.Use the cd command to change directories. With a working directory of[student@desktopX ~]$pwd/home/student[student@desktopX ~]$lsDesktop Documents Downloads Music Pictures Public Templates Videos[student@desktopX ~]$
/home/student, relative path syntax is shortest to reach
the Videos subdirectory.
The Documents subdirectory is then reached using absolute path syntax.
The shell program prompt displays, for brevity, only the last component of the current directory path. For[student@desktopX ~]$cd Videos[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd /home/student/Documents[student@desktopX Documents]$pwd/home/student/Documents[student@desktopX Documents]$cd[student@desktopX ~]$pwd/home/student[student@desktopX ~]$
/home/student/Videos,
only Videos displays.
At any time, return to the user's home directory using cd without
specifying a destination.
The prompt displays the tilde (~) character
when the user's current directory is their home directory.
The touch command normally updates a file's timestamp to the current date and time without otherwise modifying it. This is useful for creating empty files, which can be used for practice, since "touching" a file name that does not exist causes the file to be created. Using touch, practice files are created in the
Documents
and Videos subdirectories.
The ls command has multiple options for displaying attributes on files. The most common and useful are[student@desktopX ~]$touch Videos/blockbuster1.ogg[student@desktopX ~]$touch Videos/blockbuster2.ogg[student@desktopX ~]$touch Documents/thesis_chapter1.odf[student@desktopX ~]$touch Documents/thesis_chapter2.odf[student@desktopX ~]$
-l (long listing format),
-a (all files, includes hidden files),
and -R (recursive, to include the contents of all subdirectories).
The two special directories at the top of the listing refer to the current directory ([student@desktopX ~]$ls -ltotal 15 drwxr-xr-x. 2 student student 4096 Feb 7 14:02 Desktop drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Documents drwxr-xr-x. 3 student student 4096 Jan 9 15:00 Downloads drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Music drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Pictures drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Public drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Templates drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Videos[student@desktopX ~]$ls -latotal 15 drwx------. 16 student student 4096 Feb 8 16:15 . drwxr-xr-x. 6 root root 4096 Feb 8 16:13 .. -rw-------. 1 student student 22664 Feb 8 00:37 .bash_history -rw-r--r--. 1 student student 18 Jul 9 2013 .bash_logout -rw-r--r--. 1 student student 176 Jul 9 2013 .bash_profile -rw-r--r--. 1 student student 124 Jul 9 2013 .bashrc drwxr-xr-x. 4 student student 4096 Jan 20 14:02 .cache drwxr-xr-x. 8 student student 4096 Feb 5 11:45 .config drwxr-xr-x. 2 student student 4096 Feb 7 14:02 Desktop drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Documents drwxr-xr-x. 3 student student 4096 Jan 25 20:48 Downloads drwxr-xr-x. 11 student student 4096 Feb 6 13:07 .gnome2 drwx------. 2 student student 4096 Jan 20 14:02 .gnome2_private -rw-------. 1 student student 15190 Feb 8 09:49 .ICEauthority drwxr-xr-x. 3 student student 4096 Jan 9 15:00 .local drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Music drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Pictures drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Public drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Templates drwxr-xr-x. 2 student student 4096 Jan 9 15:00 Videos[student@desktopX ~]$
.) and the
parent directory (..).
These special directories exist in every directory on the system. Their
usefulness will become apparent when file management commands are practiced.
Important
File names beginning with a dot (.) indicate files
hidden from normal view using ls
and other commands. This is not a security feature.
Hidden files keep necessary user configuration files from cluttering
home directories. Many commands process hidden files only with specific
command-line options, preventing one user's configuration
from being accidentally copied to other directories or users.
To protect file contents from improper viewing requires the use of file permissions.
The cd command has many options. A few are so useful as to be worth practicing early and using often. The command cd - changes directory to the directory where the user was previous to the current directory. Watch as this user takes advantage of this behavior to alternate between two directories, useful when processing a series of similar tasks.[student@desktopX ~]$ls -R.: Desktop Documents Downloads Music Pictures Public Templates Videos ./Desktop: ./Documents: thesis_chapter1.odf thesis_chapter2.odf ./Downloads: ./Music: ./Pictures: ./Public: ./Templates: ./Videos: blockbuster1.ogg blockbuster2.ogg[student@desktopX ~]$
The cd .. command uses the[student@desktopX ~]$cd Videos[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd /home/student/Documents[student@desktopX Documents]$pwd/home/student/Documents[student@desktopX Documents]$cd -[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd -[student@desktopX Documents]$pwd/home/student/Documents[student@desktopX Documents]$cd -[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd[student@desktopX ~]$
.. hidden
directory to move up one level to the parent directory,
without needing to know the exact parent name.
The other hidden directory (.) specifies the
current directory on commands in which the current
location is either the source or destination argument, avoiding the need
to type out the directory's absolute path name.
[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd .[student@desktopX Videos]$pwd/home/student/Videos[student@desktopX Videos]$cd ..[student@desktopX ~]$pwd/home/student[student@desktopX ~]$cd ..[student@desktopX home]$pwd/home[student@desktopX home]$cd ..[student@desktopX /]$pwd/[student@desktopX /]$cd[student@desktopX ~]$pwd/home/student[student@desktopX ~]$
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