#!/bin/sh
if [ $# -gt 26 ]
then
   echo "Too many args!"
   exit 1
fi

letters="a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z"
cli="myprog"
count=1
operation=""
for argument in $*
do
   count=`expr $count + 1`
   letter=`echo $letters | head +$count | tail -1`
   cli="$cli -$letter ${argument}/${argument}.ext"
   if [ -z "$operation" ]
   then
      operation=$letter
   else
      operation="${operation}+${letter}"
   fi
done
cli="$cli -operation \"$operation\""
$cli

#!/bin/sh

echo $1 |
awk 'BEGIN {
n="abcdefghijklmnopqrstuvwxyz"
printf("myprog")}
{ for (i=1;i<=$0;i++) {
  printf(" -%s %02d/%02d.ext", substr(n,i,1), i, i)
  op=op substr(n,i,1)"+"
  }
  op=substr(op,1,length(op)-1)
  printf(" -operation \"%s\"\n",op)
}'