(((pseudocode)))
open, for reading, the file you want to change (input file)
open, for writing, a temp file.

until EOF {
     read a record from the input file.
          if you want to keep it
               write it to the temp file
}

replace the input file with the temp file

##</code><code>##

(((pseudocode)))

open input file for reading

slurp ENTIRE input file into array (@contents = <INFILE>)

close the input file

use grep to remove lines with trailing slashes from the array (@contents = grep { !/\/$/ } @contents)

open the input file for writing (this act will destroy the input file!)

write array into the file