bash question

slimm609 · 06-11-2007, 08:13 PM

Does anyone know what the difference between the following is?

TEST="this test"

echo $TEST
response: this test

echo ${TEST}
resopnse: this test

so I was wondering what the {} in the second echo statement does different then the first one

Thanks

pixellany · 06-11-2007, 08:49 PM

the { } is used for what is called "brace expansion". To get an idea what it does, do these:

echo {a,z}

echo {a..z}

In your example, the braces do nothing.

slimm609 · 06-11-2007, 09:09 PM

that does not work for variables

i think it is used for an array

like
${TEST[2]}
which would out put the 3rd entry in the array

thanks

Tinkster · 06-12-2007, 04:47 AM

Copy & paste that (including the empty line) into
an xterm or similar :}

Code:

man bash
/   Parameter Expansion

Cheers,
Tink