* Linda W <[EMAIL PROTECTED]> [061106 00:11]:
> The manpages for "my" bash's (3.1.11 on Linux and 3.1.17 on cygwin/i686),
> under Parameter Expansion, has:
>
>
> ${!prefix*}
> [EMAIL PROTECTED]
> Expands to the names of variables whose names begin with prefix,
> separated by the first character of the IFS special variable.
>
> ---
> From this, I'd expect both forms to have the same output. Is this what is
> intended and what I
> should expect?
>
> For test purposes, I set:
> IFS="<" OFS=">" # (also set "Output" FS to see if it is used
> # in the output of 'echo')
> ---
> I used 4 tests, all with prefix=U, 1st pair unquoted, 2nd pair quoted.
> input:
> echo ' * ' = ${!U*} ; \ # (line 1 - * unquoted)
> echo ' @ ' = [EMAIL PROTECTED] ; \ # (line 2 - @ unquoted)
> echo '"*"' = "${!U*}" ; \ # (line 3 - * quoted)
> echo '"@"' = "[EMAIL PROTECTED]" # (line 4 - @ quoted)
> ---
> output:
> * = UID USER # (line 1)
> @ = UID USER # (line 2)
> "*" = UID<USER # (line 3)
> "@" = UID USER # (line 4)
> ---
>
> QUESTIONS continued...
> - If the two forms are supposed to be identical, why aren't lines
> 3 & 4 the same?
> - Why do the quotes in line 3 make for different output than in line
> Why aren't the 4 lines identical? I see the IFS, "<" in line 3, but
> not in lines 1,2&4. Why isn't it in all 4 lines and, also, even the double
> quotes make a
> difference when expanding variables, why
> aren't lines 3&4 the same?
>
>
As Yakov pointed out, this is the wrong list, but I will answer anyway.
${!prefix*} and [EMAIL PROTECTED] (unquoted) are the same. However, inside
double quotes, "${!prefix*}" expands to a single word (and requires IFS
separation between the names that match the prefix), while "[EMAIL PROTECTED]"
expands to one word for each name that matches, and hence is already
separated by quoting.
I do not see this described in the man page under ${!prefix*}, but if
you look earlier in the man page under Special Parameters, it describes
the difference between $* and [EMAIL PROTECTED] Also, under Arrays (between
Special
Parameters and Parameter Expansion), it says that the difference between
${name[*]} and [EMAIL PROTECTED] is analogous to the difference between $* and
$@, so I imagine that the same applies to !prefix.
...Marvin
