util_filter
-----------

util_filter(COMMAND,INPUT)
     : It executes the filter program COMMAND with the INPUT and returns the output of the filter as a string.

util_filter(COMMAND,INPUT | ENV=key0)
     : This function allows optional variables ENV

Example:

      util_filter("sort","cat\ndog\ncentipede\n");

util_find_and_replace
---------------------

util_find_and_replace(W,S,WNEW)
     : It replaces W in S by WNEW. Arguments must be a list of ascii codes.

util_find_substr
----------------

util_find_substr(W,S)
     : It returns the position of W in S. If W cannot be found, it returns -1. Arguments must be a list of ascii codes.

util_index
----------

util_index(V)
     : It returns the name part and the index part of V.

Example:

      util_index(x_2_3)

References
     util_v

util_load_file_as_a_string
--------------------------

util_load_file_as_a_string(F)
     : It reads a file F as a string.

util_part
---------

util_part(S,P,Q)
     : It returns from Pth element to Qth element of S.

util_read_file_as_a_string
--------------------------

util_read_file_as_a_string(F)
     : It reads a file F as a string.

util_remove_cr
--------------

util_remove_cr(S)
     : It removes cr/lf/tabs from S. Arguments must be a list of ascii codes.

util_v
------

util_v(V,L)
     : It returns a variable indexed by L.

Example:

      util_v("x",[1,3]);

References
     util_index

util_write_string_to_a_file
---------------------------

util_write_string_to_a_file(FNAME,S)
     : It writes a string S to a file FNAME.