Overview of changes:

 *  Fixed coerce__noctl() to actually do something

    Turns out that the function could not ever work properly since
    Perl's tr/// operator does not support POSIX character classes like
    traditional tr(1) does.  The expression was replaced with s///
    variant, preserving the same character range.

    Also it will now *replace* characters $COERCE__REPCHAR, instead of
    removing them.  (Removing behavior can be achieved by setting the
    variable to empty string.)

mkit.ini

 [project]
-    version     = 0.10.16
+    version     = 0.10.17
     codename    = FloatingPointError
     name        = Shellfu
     tagline     = Shell dot on steroids

src/include-sh/coerce.sh

 
 coerce__noctl() {
     #
-    # Remove non-printable characters
+    # Replace non-printable characters with $COERCE__REPCHAR
     #
-    perl -CS -Mutf8 -pe 'tr|[:graph:]\n\t ||c;'
+    # Keep only characters that have grapgical representation ([:graph:] POSIX
+    # class), newline, tab and space.  Replace rest with $COERCE__REPCHAR.
+    #
+    perl -CS -Mutf8 -pe "s|[^[:graph:] \t\n]|$COERCE__REPCHAR|g"
 }
 
 coerce__nofdraw() {