Question

Here is an example

Interface {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} IP-Address {} {} {} {} {} OK? Method Status {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {Protocol
FastEthernet0/0} {} {} {} {} {} {} {} {} {} {} {} unassigned {} {} {} {} {} YES unset {} administratively down down {} {} {} {
FastEthernet0/1} {} {} {} {} {} {} {} {} {} {} {} unassigned {} {} {} {} {} YES unset {} administratively down down

I want remove {} in this.
I assumed all the above string interface variable

set interface [string trimright [string trimleft $interface "{}"] "{}"]

but it doesn’t work. How to remove the {} in my example?

Answer 1

I suspect you’re doing this: starting with a string and trying to split it into words, only Tcl’s split command is producing a list with lots of empty values:

set input "Interface                  IP-Address      OK? Method Status                ProtocolFastEthernet0/0            unassigned      YES unset  administratively down down    FastEthernet0/1            unassigned      YES unset  administratively down down"
set fields [split $input]  ;# ==> Interface {} {} {} ...

Tcl’s split splits on individual whitespace characters by default (unlike awk or perl that splits on consecutive whitespace chars).

You can some choices to make your life easier:

1) use regexp to find all “words”

set fields [regexp -inline -all {\S+} $input] 

2) use the textutil package for a split command that acts like you seem to expect:

package require textutil
set fields [textutil::splitx $input]