The `obigrep` command is somewhat analogous to the standard Unix `grep` command. It selects a subset of sequence records from a sequence file. A sequence record is a complex object consisting of an identifier, a set of attributes (a key, defined by its name, associated with a value), a definition, and the sequence itself. Instead of working text line by text line like the standard Unix tool, `obigrep` selection is done sequence record by sequence record. A large number of options allow you to refine the selection on any element of the sequence. `obigrep` allows you to specify multiple conditions simultaneously (which take on the value `TRUE` or `FALSE`) and only those sequence records which meet all conditions (all conditions are `TRUE`) are selected. `obigrep` is able to work on two paired read files. The selection criteria apply to one or the other of the readings in each pair depending on the mode chosen (**\--paired-mode** option). In all cases the selection is applied in the same way to both files, thus maintaining their consistency.
