lassign(n) Tcl Built-In Commands lassign(n) 







lassign - Assign list elements to variables








lassign list varName ?varName ...?












This command treats the value list as a list and assigns
    successive elements from that list to the variables given by the
    varName arguments in order. If there are more variable names than
    list elements, the remaining variables are set to the empty string. If there
    are more list elements than variables, a list of unassigned elements is
    returned.








An illustration of how multiple assignment works, and what happens
    when there are either too few or too many elements.




lassign {a b c} x y z       ;# Empty return
puts $x                     ;# Prints "a"
puts $y                     ;# Prints "b"
puts $z                     ;# Prints "c"
lassign {d e} x y z         ;# Empty return
puts $x                     ;# Prints "d"
puts $y                     ;# Prints "e"
puts $z                     ;# Prints ""
lassign {f g h i} x y       ;# Returns "h i"
puts $x                     ;# Prints "f"
puts $y                     ;# Prints "g"



The lassign command has other uses. It can be used to create the analogue
  of the “shift” command in many shell languages like this:



set ::argv [lassign $::argv argumentToReadOff]










lindex(n), list(n), lset(n), set(n)










assign, element, list, multiple, set, variable







  

    8.5
    Tcl