title: What is strlen actually doing?
body: <p>This is subroutine strlen</p>
  
  <pre><code>      subroutine strlen(string,i1,i2)
        character string*(*)
        do 10 i=len(string),1,-1
          if(string(i:i).ne.' ')then
            i2=i
            goto 11
          endif
     10   continue
     11 do 20 i=1,len(string)
          if(string(i:i).ne.' ')then
            i1=i
            return
          endif
     20   continue
        return
        end
  </code></pre>
  
  <p>In the main</p>
  
  <pre><code> if(nfil.lt.0)then
      call strlen(cpar,i1,i2)
      open(unit=10,file=cpar(i1:i2),status='old')
  </code></pre>
  
  <p>If cpar is declared
        character cpar*(*)</p>
  
  <p>Does it exist any rule or limitation regarding the name of the cpar to be openned properly?</p>
  
  <p>My hx263on.sens(cpar) can not be read.Why?</p>