Trailing Slash or Not?

RobInRockCity · 02-26-2015, 09:36 PM

When I type in a path to a directory - whether it be in SSH or a config file or wherever - should I end it with a trailing slash or not?

For example...

Code:

/home/rob123/temp/

or

Code:

/home/rob123/temp

Rob

goumba · 02-26-2015, 11:22 PM

I really don't think it matters, commands like 'cd' work either way.

FWIW: using bash, if I use tab to complete a path, it adds the trailing slash. So, if you want to be sure you're operating on a directory, I would add it.

astrogeek · 02-26-2015, 11:31 PM

It doesn't matter for most things, as long as it is unambiguous that it is a directory.

It does matter when using rsync however... from man rsync:

Quote:

...A trailing slash on the source changes this behavior to avoid creating an additional directory level at
the destination. You can think of a trailing / on a source as meaning "copy the contents of this direc-
tory" as opposed to "copy the directory by name", but in both cases the attributes of the containing
directory are transferred to the containing directory on the destination.

With bash autocomplete, presence or absence of a tailing slash added by the shell will allow you to visually distinguish between a directory and a symlink to a directory. This behavior can also vary with inputrc directive show-all-if-ambiguous, I think.

It is usually important when used in config files and varies per application.

RobInRockCity · 02-27-2015, 09:50 AM

Quote:

Originally Posted by goumba

So, if you want to be sure you're operating on a directory, I would add it.

That has been the approach I have taken so far.

Just wasn't sure, because when I look at some things online or even my php.ini file, I have seen it both ways.

I prefer to be "precise"!!

Rob

RobInRockCity · 02-27-2015, 09:51 AM

Quote:

Originally Posted by astrogeek

It doesn't matter for most things, as long as it is unambiguous that it is a directory.

It does matter when using rsync however... from man rsync:

Quote:

...A trailing slash on the source changes this behavior to avoid creating an additional directory level at
the destination. You can think of a trailing / on a source as meaning "copy the contents of this direc-
tory" as opposed to "copy the directory by name", but in both cases the attributes of the containing
directory are transferred to the containing directory on the destination.

Interesting point!

Thanks,

Rob

suicidaleggroll · 02-27-2015, 10:11 AM

If you leave off the trailing slash, it can point to a file or a directory. If you include the trailing slash it can only point to a directory. This can be advantageous in certain cases. For example, say you want to copy A (a file) into B (a directory).

You could use either

Code:

cp A B

or

Code:

cp A B/

If B already exists and is a directory, the two commands are interchangeable, but if B doesn't already exist, or if it does already exist and is a file, the behavior will be quite different.

The former command will just copy the file A to the file B, overwriting its previous contents if necessary.

The latter command will ONLY do anything if B already exists and is a directory. If B doesn't exist or if B is a file, the latter command will throw an error, allowing you to correct the command before accidentally overwriting the file B or creating copies of A where you don't want them.

For that reason, when I'm referring to a directory, I always put a trailing slash on the end so that if I make a mistake in the name it will throw an error rather doing something I don't want it to do.