Introduction
       ------------------------------------------------------------
       
       This extension for efind makes it possible to filter text
       files by their content.
       
       
       Available functions
       ------------------------------------------------------------
       
       text_contains(string: query)
       ----------------------------
       
       Tests if the text file contains query. Returns the line
       number of the first occurrence.
       
         $ efind . 'text_contains("foo") or text_contains("bar")'
       
       
       head_contains(string: query, integer: limit)
       --------------------------------------------
       
       Tests if the first limit lines of the text file contain
       query. Returns the line number of the first occurrence.
       
         $ efind . 'head_contains("baz", 20)'
       
       
       tail_contains(string: query, integer: limit)
       --------------------------------------------
       
       Tests if the last limit lines of the text file contain
       query. Returns the line number of the first occurrence.
       
         $ efind . 'tail_contains("foobar", 20)'
       
       
       text_startswith(string: query)
       ------------------------------
       
       Tests if the text file contains a line starting with query.
       Returns the line number of the first occurrence.
       
         $ efind . 'text_startswith("foo") or text_contains("bar")'
       
       
       head_startswith(string: query, integer: limit)
       ----------------------------------------------
       
       Tests if the first limit lines of text file contain a line
       starting with query. Returns the line number of the first
       occurrence.
       
         $ efind . 'head_startswith("baz", 20)'
       
       
       tail_startswith(string: query, integer: limit)
       ----------------------------------------------
       
       Tests if the last limit lines of text file contain a line
       starting with query. Returns the line number of the first
       occurrence.
       
         $ efind . 'tail_startswith("foobar", 20)'
       
       
       text_endswith(string: query)
       ----------------------------
       
       Tests if the text file contains a line ending with query.
       Returns the line number of the first occurrence.
       
         $ efind . 'text_endswith("foo") or text_contains("bar")'
       
       
       head_endswith(string: query, integer: limit)
       --------------------------------------------
       
       Tests if the first limit lines of text file contain a line
       ending with query. Returns the line number of the first
       occurrence.
       
         $ efind . 'head_endswith("baz", 20)'
       
       
       tail_endswith(string: query, integer: limit)
       --------------------------------------------
       
       Tests if the last limit lines of text file contain a line
       ending with query. Returns the line number of the first
       occurrence.
       
         $ efind . 'tail_endswith("foobar", 20)'
       
       
       count_lines()
       -------------
       
       Returns the number of lines.
       
         $ efind . 'count_lines()>100'
       
       
       count_match(string: query)
       --------------------------
       
       Returns the number of lines containing query.
       
         $ efind . 'count_match("foo")=5'
       
       
       count_prefix(string: query)
       ---------------------------
       
       Returns the number of lines starting with query.
       
         $ efind . 'count_prefix("bar")>=17'
       
       
       count_suffix(string: query)
       ---------------------------
       
       Returns the number of lines ending with query.
       
         $ efind . 'count_suffix("baz")=100'
       
       
       Links
       ------------------------------------------------------------
 (BIN) master.zip
 (HTM) GitHub