Add Fibonacci in Tcl (#5055)

Author: pascalecu

archive/t/tcl/fibonacci.tcl

@@ -0,0 +1,21 @@
+proc usage {} {
+    puts "Usage: please input the count of fibonacci numbers to output"
+    exit 1
+}
+
+if {$argc != 1} { usage }
+
+set count [lindex $argv 0]
+
+if {![string is integer -strict $count] || $count < 0} { usage }
+
+set a 1
+set b 1
+
+for {set i 1} {$i <= $count} {incr i} {
+    puts "$i: $a"
+
+    set next [expr {$a + $b}]
+    set a $b
+    set b $next
+}