tasks a-s

Task/Runtime-evaluation/Tcl/runtime-evaluation-1.tcl

@@ -0,0 +1,4 @@
+set four 4
+set result1 [eval "expr {$four + 5}"]           ;# string input
+
+set result2 [eval [list expr [list $four + 5]]] ;# list input

Task/Runtime-evaluation/Tcl/runtime-evaluation-2.tcl

@@ -0,0 +1,21 @@
+# Create an interpreter with a default set of restrictions
+interp create -safe restrictedContext
+
+# Our secret variable
+set v "secret"
+
+# Allow some guarded access to the secret from the restricted context.
+interp alias restrictedContext doubleSecret {} example
+proc example {} {
+    global v
+    lappend v $v
+    return [llength $v]
+}
+
+# Evaluate a script in the restricted context
+puts [restrictedContext eval {
+    append v " has been leaked"
+    catch {file delete yourCriticalFile.txt} ;# Will be denied!
+    return "there are [doubleSecret] words in the secret: the magic number is [expr {4 + 5}]"
+}];       # --> there are 2 words in the secret: the magic number is 9
+puts $v;  # --> secret secret

Task/Runtime-evaluation/Tcl/runtime-evaluation-3.tcl

@@ -0,0 +1,8 @@
+set i [interp create]
+interp limit $i commands -value [expr [$i eval info cmdcount]+20] -granularity 1
+interp eval $i {
+    set x 0
+    while {1} { # Infinite loop! Bwahahahaha!
+        puts "Counting up... [incr x]"
+    }
+}