[clenny]

I never ask a dumb question. However, my uninformed questions sometimes reveal how little I know about a subject. Okay, now that we've established that, here is my question. When editing a sources.list list, what exactly does it mean to uncomment a line? Does that mean you add another # sign in front of the # sign already there? The reason I ask is trying to uncomment lines is what led to my many problems in the first place. I did some searches and such but didn't find a specific answer to that question. Thanks in advance.

[prunejuice]

Originally Posted by clenny

I never ask a dumb question. However, my uninformed questions sometimes reveal how little I know about a subject. Okay, now that we've established that, here is my question. When editing a sources.list list, what exactly does it mean to uncomment a line? Does that mean you add another # sign in front of the # sign already there? The reason I ask is trying to uncomment lines is what led to my many problems in the first place. I did some searches and such but didn't find a specific answer to that question. Thanks in advance.

If you add # before the source, that repository will not be used.
If you remove the # before the source, the repository link is active.

Basically, adding # before a line means "skip this".

[lotuseclat79]

A '#' is a comment in shell script language at the front of the line or whereever it occurs in a line to the end of the line, so its no coincidence that it is used to mean that in lists. Same as non-operational, not active, skip this, etc.

To uncomment a line then means to do the following, given the following line:
# execute this

modify it to be:
# execute this
execute this

Note: I kept the original commented line for documentation to remember that a change has occured. You can also add a date/initials like:
# execute this uncommented by mjw on 11/19/2006
execute this

-- Tom

[Bartender]

Yeah, but to get back to what clenny's asking, what's the difference between "#" and "##"? I've wondered about that too...

[fenderfreek]

As far as I know, # and ## should do the same thing. The second '#' should be treated as part of the comment.

[lotuseclat79]

To uncomment a line, take out the '#' at the beginning of the line. If there is another '#' following the first, as in "## ...rest of line", then the line is commented out by the remianing '#'.

-- Tom

[clenny]

Originally Posted by lotuseclat79

To uncomment a line, take out the '#' at the beginning of the line. If there is another '#' following the first, as in "## ...rest of line", then the line is commented out by the remianing '#'.

-- Tom

Okay, at the risk of dwelling on semantics, please explain what is meant by "commented out". Uncomment, I understand, that means to more or less activate a command that was inactive.. So I'm not sure I understand the difference between having 1 or 2 ## at the beginning of a line. It seems you are saying 2 #s are redundant. TIA

[fenderfreek]

Having two ('##') would be redundant. Once it parses a '#' character, everything else on the line is ignored, including the second '#'. Different characters are used for comments in different things. Java, for example, uses '//' to denote a comment, and just one by itself won't do.

[lotuseclat79]

Originally Posted by clenny

Okay, at the risk of dwelling on semantics, please explain what is meant by "commented out". Uncomment, I understand, that means to more or less activate a command that was inactive.. So I'm not sure I understand the difference between having 1 or 2 ## at the beginning of a line. It seems you are saying 2 #s are redundant. TIA

What fenderfreek said.

The '#' works on a line basis until the end of the line is reached. If the first one is erased and is followed by another '#' later on in the line, everything up until the second '#' (i.e. when the first one is erase) is activated, and everthing after the second '#' is inactive due to being "commented out", i.e. by the second '#'.

-- Tom

[Bartender]

clenny -
I'm still not sure I understand the # vs. ## thing. How about you?
All I need to know is whenever the OS scans a list for instructions, if it sees # at the beginning of a line it ignores that line and moves on. I don't think the computer cares if there's one # or a dozen of 'em.

[fenderfreek]

Well, it does care...sort of. Let me try my hand at some examples

Assume the following is some entry that uses #'s to denote comments -

#This entire line will be ignored 
This will not be ignored # but this will

and

##This is ignored too.

If I change it to -

#This is ignored too

it treats it just the same.
Whether you use one or a million comment delineators, the first one is what starts the comment and the others are just pretty.

[clenny]

Thanks guys, I think I get it now. And I think I now know how I screwed up my sources.list list. I hope i don't have too many more screw ups while I'm learning Linux.