Shell Programming and Scripting

awk 'function find(val)
      {
        p=$0
        while( (inx=index(p,val))>0 )
        {
           print val, inx
           p=substr(p,inx+1)
        }
     }
     /123/ {find("123") }
     /456/ {find("456") } 
     '   filename

echo "123 index"
sed -n 's/123/\n/gp' 1|awk 'BEGIN{i=1}{i+=length($0);a[NR]=i;i+=3}END{for(i in a){print a[i]}}'|sort -n
echo "456 index"
sed -n 's/456/\n/gp' 1|awk 'BEGIN{i=1}{i+=length($0);a[NR]=i;i+=3}END{for(i in a){print a[i]}}'|sort -n