initial commit

bash/hamming/hamming.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+# set to 0 to disable log function output, 1 otherwise
+debug=0
+
+# echoes $1, then exit 1
+die ()  {
+    echo "$1"
+    exit 1
+}
+
+# log function takes 1 argument which is echoed if $debug is > 0
+# todo: Ad another argument (mask?) to selectively log portions of code
+log () {
+    (( $debug )) && echo "$1"
+}
+
+# check basic errors
+(( $# != 2 )) && die "Usage: hamming.sh <string1> <string2>"
+(( ${#1} != ${#2} )) && die "left and right strands must be of equal length"
+
+# compare strings
+declare -i cur hamming=0
+
+for (( cur=0; cur < ${#1}; cur++ )); do
+    log "$cur ${1:$cur:1} ${2:$cur:1}"
+    c1="${1:$cur:1}"
+    c2="${2:$cur:1}"
+    [[ "$c1" != "$c2" ]] && ((hamming++))
+    log "hamming in loop=$hamming"
+done
+
+echo "$hamming"
+exit 0
+
+# Indent style for emacs
+# Local Variables:
+# sh-basic-offset: 4
+# sh-indentation: 4
+# indent-tabs-mode: nil
+# comment-column: 60
+# End: