Data commit

Task/Middle-three-digits/UNIX-Shell/middle-three-digits.sh

@@ -0,0 +1,23 @@
+function middle3digits
+{
+  typeset -i n="${1#-}"
+  typeset -i l=${#n}
+  if (( l < 3 )); then
+    echo >&2 "$1 has less than 3 digits"
+    return 1
+  elif (( l % 2 == 0 )); then
+    echo >&2 "$1 has an even number of digits"
+    return 1
+  else
+    echo ${n:$((l/2-1)):3}
+    return 0
+  fi
+}
+
+# test
+testdata=(123 12345 1234567 987654321 10001 -10001 -123 -100 100 -12345 1 2 -1
+          -10 2002 -2002 0)
+for n in ${testdata[@]}; do
+  printf "%10d: " $n
+  middle3digits "$n"
+done