how to deal with character "-",it is a part of variable name

lutian · 11-12-2008, 03:26 AM

I meet a issue,someone define project name with "-" character,

how to deal with "-" in bash scripts,

"-" as part of variable name
set aa-bb="AAAA'
echo ${aa-bb}

David the H. · 11-12-2008, 06:21 AM

Well, first off, just to be sure, have you noticed that you have mismatched quotation marks around the variable value in your example above?

jan61 · 11-12-2008, 01:13 PM

Moin,

it's not possible to use "-" in variable names. See "man bash":

Quote:

name
A word consisting only of alphanumeric characters and underscores, and beginning
with an alphabetic character or an underscore. Also referred to as an identi-
fier.

Jan

lutian · 11-12-2008, 06:48 PM

Quote:

Originally Posted by jan61

Moin,

it's not possible to use "-" in variable names. See "man bash":

Jan

yes,vaiable names cannot use "-",

In my office, someone define a project name with "-" on cvs,

in my scripts program,how to deal with a project name have "-" character,

Thanks

Sergei Steshenko · 11-12-2008, 07:03 PM

Quote:

Originally Posted by lutian

yes,vaiable names cannot use "-",

In my office, someone define a project name with "-" on cvs,

in my scripts program,how to deal with a project name have "-" character,

Thanks

Change the language to, say, Perl and use hash keys as variable names -
hash key can be any string.

ta0kira · 11-12-2008, 07:04 PM

That doesn't seem like it should be any problem. In what way doesn't it work? Your example used "-" in a variable name, not in anything passed as a command-line argument.
ta0kira

lutian · 11-12-2008, 08:00 PM

Quote:

Originally Posted by ta0kira

That doesn't seem like it should be any problem. In what way doesn't it work? Your example used "-" in a variable name, not in anything passed as a command-line argument.
ta0kira

When I put the project name to variable name,the scripts dosenot work.

ta0kira · 11-12-2008, 10:01 PM

Can you post it? You example doesn't reflect that.
ta0kira

lutian · 11-13-2008, 02:42 AM

Quote:

Originally Posted by ta0kira

Can you post it? You example doesn't reflect that.
ta0kira

Have been solved,

The root cause is variable name using "-",

is not variable with "-",

I define a new variable name without "_",that is OK now.

Thanks veryone.

Sergei Steshenko · 11-13-2008, 01:45 PM

Quote:

Originally Posted by lutian

Have been solved,

The root cause is variable name using "-",

is not variable with "-",

I define a new variable name without "_",that is OK now.

Thanks veryone.

It's not OK and will never be with your approach.

Suppose you have two projects:

foo-bar
foo_bar
.

How are you going to distinguish them ?