If command ends with "\ ", the space is ignored

## Summary
Last space is trimmed on a line. Leads to undeserved errors.

## Steps to reproduce
In basically any challenge:
    cat README | grep \ 
* Please note the space after backslash.

## Expected
 Some text output

## What happens
    Usage: grep [OPTION]... PATTERN [FILE]...
    Try 'grep --help' for more information.

