Repeat-By:
a=111.1
echo ${a//[0-9]/x}
correctly gives "xxx.x", but
echo ${a//[0-9]/*}
gives a listing of files in current directory. Seems that the "*"
is expanded before replacing the pattern.
It workes the right way at least up to bash-3.1.17(1)-release
But if you set
a=111
it doesn't even work in 3.1.17 right.
The pathname expansion of "*" is not done until after the parameter
expansion substitution. That is the documented behavior. The following
example shows that echo of the "***.*" pattern matches files and
directories that have a "." in their name. Setting a to "111" results
in a pathname pattern of "***" that matches all of the files.
Double quoting the substitution prevents pathname expansion.
$ echo $BASH_VERSION
3.2.25(1)-release
$ touch a b c.d e.f
$ ls
a b c.d e.f
$ a=111.1
$ echo ${a//[0-9]/*}
c.d e.f
$ echo "${a//[0-9]/*}"
***.*
$ a=111
$ echo ${a//[0-9]/*}
a b c.d e.f
$ echo "${a//[0-9]/*}"
***
$