concat - Join lists together

       This  command joins each of its arguments together with spaces after trimming leading and trailing white-
       space from each of them.  If all of the arguments are lists, this has the same  effect  as  concatenating
       them into a single list.  Arguments that are empty (after trimming) are ignored entirely.  It permits any
       number of arguments; if no args are supplied, the result is an empty string.

       Although  concat  will  concatenate  lists,  flattening  them  in  the  process  (so giving the following
       interactive session):

              %concat a b {c d e} {f {g h}}
              abcdef{gh}

       it will also concatenate things that are not lists, as can be seen from this session:

              %concat " a b {c   " d "  e} f"
              ab{cde}f

       Note also that the concatenation does not remove spaces from the middle of values, as can be seen here:

              %concat "a   b   c" { d e f }
              abcdef

       (i.e., there are three spaces between each of the a, the b and the c).

       For true list concatenation, the list command should be used with expansion of each input list:

              % list {*}"a   b   c" {*}{ d e f }
              abcdef

       concatenate, join, list

Tcl                                                    8.3                                          concat(3tcl)

       concat - Join lists together

append(3tcl), eval(3tcl), join(3tcl), list(3tcl)

concat ?argarg...?
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