helper function

pert

@@ -3,19 +3,34 @@
 # help text
 if [ -z "$1" ] || [[ "$1" =~ [-]*(help|h) ]]; then
     echo -e "\nA command line PERT calculator for quick estimates."
-    echo -e "Comma separated task list in the form \"1,2,12 4,5,9 2,3,6\", where whitespace separates tasks.\n"
-    echo -e "Usage:\n\tpert [optimistic,realistic,pessimistic]\n"
+    echo -e "\nComma separated task list in the form \"1,2,12 4,5,9 2,3,6\", where whitespace separates tasks."
+    echo -e "\nUsage:\n\tpert [optimistic,realistic,pessimistic]\n"
+    echo -e "Example:"
+    echo -e "\tpert 1,3,4"
+    echo -e "\tpert 10,15,20 5,7,10"
+    echo -e "\tpert \"1,2,3\" \"15,17,20\"\n"
     exit 1
 fi
 
+# helper
+function _calc 
+{
+    scale=2
+    echo "scale=$scale; $@" | bc -l | sed 's/^\./0./'
+}
+
+function _divider
+{
+    divider=------------------------------
+    divider=" "$divider$divider$divider
+    width=83
+    
+    printf "%$width.${width}s\n" "$divider"
+}
+
 header="\n %-12s |%11s |%10s |%12s |%9s |%7s |%9s\n"
 format=" %-12s |%11s |%10s |%12s |%9s |%7s |%9s\n"
 
-divider=------------------------------
-divider=" "$divider$divider$divider
-width=83
-
-scale=2
 counter=0
 total_estimate=0
 total_standard_deviation=0
@@ -39,27 +54,26 @@ for var in "$@"; do
     
     # header
     if [[ $counter = 1 ]]; then
-        printf "$header" "task" "optimistic" "realistic" "pessimistic" "duration" "risk" "variance"
-        printf "%$width.${width}s\n" "$divider"
+        printf "$header" "#" "optimistic" "realistic" "pessimistic" "duration" "risk" "variance"
+        _divider
     fi
     
     # check values
     if [ -z "$o" ] || [ -z "$r" ] || [ -z "$p" ]; then
-        #echo -e "\tbad input [$o,$r,$p]"
         printf "$format" "$counter. bad input" $o $r $p
     else
     
         # pert estimate
-        pert_estimate=$(echo "scale=$scale; ($o+4*$r+$p)/6" | bc -l | sed 's/^\./0./')
-        total_estimate=$(echo "scale=$scale; $total_estimate + $pert_estimate" | bc -l | sed 's/^\./0./') 
+        pert_estimate=$(_calc "($o+4*$r+$p)/6")
+        total_estimate=$(_calc "$total_estimate + $pert_estimate") 
         
         # standard deviation
-        standard_deviation=$(echo "scale=$scale; ($p-$o)/6" | bc -l | sed 's/^\./0./')
-        total_standard_deviation=$(echo "scale=$scale; $total_standard_deviation + $standard_deviation" | bc | sed 's/^\./0./')
+        standard_deviation=$(_calc "($p-$o)/6")
+        total_standard_deviation=$(_calc "$total_standard_deviation + $standard_deviation")
 
         # variance
-        variance=$(echo "scale=$scale; $standard_deviation*$standard_deviation" | bc -l | sed 's/^\./0./')
-        total_variance=$(echo "scale=$scale; $total_variance + $variance" | bc | sed 's/^\./0./')
+        variance=$(_calc "$standard_deviation * $standard_deviation")
+        total_variance=$(_calc "$total_variance + $variance")
     
         # row        
         printf "$format" "$counter. task" $o $r $p $pert_estimate $standard_deviation $variance
@@ -70,7 +84,7 @@ done
 if [[ $total_estimate > 0 ]]; then
 
     # footer        
-    printf "%$width.${width}s\n" "$divider"
+    _divider
     printf "$format" "summary" "-" "-" "-" $total_estimate $total_standard_deviation $total_variance
     
     echo -e "\nThree point estimate:"