What is the meaning of ./ before a given path?

Question

I've been told to run this:

./yiic message ./app/messages/config.php

But I don't understand the ./ meaning, can anyone clarify please.

Note: Believe me, we can't google that. I've tried:

./ meaning ./ ubuntu

It was the same as nothing. :(

Answer 1

./ or just . is unix shorthand for the current directory.

You need to specify it when the current directory is not in your PATH. The PATH is the list of folders searched when you run a program. (You can determine it by writing echo $PATH.) If an executable file is not in your PATH, to run it you need to specify the folder it's in. You could do this by giving the full path to the file, but if the file is in the current directory, you can use ./ as shorthand.

Similarly, ../ or just .. is shorthand for the directory above the current one.

Answer 2

Every directory in the command line has two "special directories" called . and ... These are shorthand for, respectively, the current directory and the directory containing the current directory.

So for example, cd ./more/directory/names just means, "start at the current directory and continue in the path." Similarly, the command cd .. means, "change one directory up.

If you want the name of your current directory, you can use the pwd command. Also, if you use the -a flag for ls, you can see these two special directories. That is, ls -a will output a list starting with . and ...

Answer 3

It means to start from the current directory path.

Let's assume you have a path like this:

/usr/ /usr/bin/ /usr/local/bin

and inside /usr/bin/ there is an executable called yiic.

If you issue yiic it would start the one in /usr/bin/.

By issueing ./yiic you tell the system to look inside the current directory for this executable.

Answer 4

Others have already explained what . and .. means (current directory and the parent directory respectively). This applies to all path names.

When you open a terminal, you usually start in your home directory: ~ (which expands to /home/username). The below paths are all equivalent, providing your current working directory is /home/username:

• /home/username
• .
• ../username
• ../../home/username
• ../../../home/username (the parent directory of / is still /)
• ./././././. (the current directory in the current directory in the ...)
• ./ (trailing slashes are allowed for directories)
• /home////username/// (and so are multiple slashes)

Do not confuse ./program with . program. ./program runs a file in the current directory with the execute bit set. . ./program is a bash thing and can alternatively be written as source ./program which reads bash commands from the program file in the current directory and executes them in the current shell.

If you wonder why you can just run gedit instead of /usr/bin/gedit and not program instead of ./program or /home/username/program, see the related question:

• What are $PATH and ~/bin? How can I have personal scripts?