- Added solution from Joelle Maslak.

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+#!/bin/bash
+
+# Challenge:
+#   Write a script or one-liner to remove leading zeros from positive
+#   numbers.
+#
+# Assumptions:
+#   The first question was, "What do you do about non-positive numbers?
+#
+#     I assumed we just wanted to print non-numbers or non-positive
+#     numbers "as-is", without removing anything. But we still wanted to
+#     handle them, otherwise this would be a shorter program.
+#
+#     Zero is neither postiive or negative.
+#
+#   Likewise, what is a number?
+#
+#     I assumed any number that is provided in decimal format is a
+#     number. Numbers expressed in scientific notation, non-latan
+#     script, or fractions (1/2) are not treated as positive numbers, so
+#     they are printed without modification.
+#
+#   Example input/output
+#
+#     INPUT     OUTPUT
+#     0         0
+#     0.0       0.0
+#     00.00     00.00
+#     -1        -1
+#     -01       -01
+#     1.0       1.0
+#     1.0000    1.0000
+#     00.       00.         (not a standard-formatted number)
+#     0.0       .0          (leading zero removed)
+#     001       1
+#     abc       abc
+#     01a       01a
+#     001 2     001 2
+#
+# Implementation:
+#   "perl6 -e" simply executes the first argument, the script.  We'll
+#   describe the script later.  The final argument, "$*", is just the
+#   arguments passed to this shell script, passed as the first argument
+#   to the one-liner.
+#
+#   The script used takes the first command line parameter (@*ARGS[0])
+#   and does a non-destructive substitution on it (using the S///
+#   operator followed by a "with" to reference the source).
+#
+#   The regex basically removes zeros at the front of one of two
+#   different patterns - this pattern could be simplified as two
+#   regexes:
+#
+#     S/ ^ 0+ ( <[0..9]>* \. <[0..9]>+ ) $ /$0/
+#
+#       - and -
+#
+#     s/ ^ 0+ ( <[1..9]> <[0..9]>* ) $ /$0/
+#
+#   The first one handles numbers with a decimal point.  It removes all
+#   leading zeros in front of the decimal point, in a pretty
+#   straightforward way.  Note that 0.0 would become .0, removing the
+#   leading zero.
+#
+#   The second regex above handles non-zero positive numbers without a
+#   decimal point.  But we don't want to remove leading zeros for zero
+#   itself.  I.E. 00 is not a positive number (it's zero, it's neither
+#   positive or negative), so it should stay 00.  So any number starting
+#   with a zero must have at least one non-zero digit for leading zeros
+#   to be removed.
+#
+#   These two regexes were then combined form what is in the one-liner
+#   below.
+#
+perl6 -e 'say S/ ^ 0+ ( ( <[0..9]>* \. <[0..9]>+ ) | ( <[1..9]> <[0..9]>* ) ) $ /$0/ with @*ARGS[0]' "$*"
+
+