Robustly select lines from file; can replace the head and tail shell commands and do even more

usage: get_line {--range|-r} {+n|-n|i|i..j|i:j|i,j[,...]} [-i FILE] [--rand] [-v] (1 <= i [<= j] <= N; N = nb. lines in FILE) -v invert the selection of lines (like 'grep -v') --rand randomize selected lines before writing them out --NxCV <int> several folds cross validation: cut input file into N

     partitions then create N traininig files and N test files
     (all other get_line options will be ignored)

-i <filename> where to read lines from (default=stdin) -o <filename> where to write lines to (default=stdout) --range {+n|-n|i|i..j|i,j[,...]}: line selection policy;

      (+n => top n lines;
       -n => last n lines;
       n => only line n;
       i..j => lines i to j;
       i:j => top i lines and last j lines;
       i,j[,...] => only lines i,j, ...

-r alias for --range -help Display this list of options --help Display this list of options