hash [ -Ldfmrv ] [ name[=value] ] ...
       hash can be used to directly modify the contents of the  command
       hash  table,  and  the named directory hash table.  Normally one
       would modify these tables by modifying one's PATH (for the  com-
       mand  hash  table)  or  by creating appropriate shell parameters
       (for the named directory hash table).  The choice of hash  table
       to  work  on  is determined by the -d option; without the option
       the command hash table is used, and with the  option  the  named
       directory hash table is used.

       A command name starting with a / is never hashed, whether by ex-
       plicit use of the hash command or otherwise.  Such a command  is
       always found by direct look up in the file system.

       Given  no  arguments,  and neither the -r or -f options, the se-
       lected hash table will be listed in full.

       The -r option causes the selected hash table to be emptied.   It
       will  be subsequently rebuilt in the normal fashion.  The -f op-
       tion causes the selected hash table to be fully rebuilt  immedi-
       ately.   For the command hash table this hashes all the absolute
       directories in the PATH, and for the named directory hash  table
       this adds all users' home directories.  These two options cannot
       be used with any arguments.

       The -m option causes the  arguments  to  be  taken  as  patterns
       (which  should  be  quoted)  and  the elements of the hash table
       matching those patterns are printed.  This is the  only  way  to
       display a limited selection of hash table elements.

       For  each name with a corresponding value, put `name' in the se-
       lected hash table, associating it with the pathname `value'.  In
       the  command hash table, this means that whenever `name' is used
       as a command argument, the shell will try to  execute  the  file
       given by `value'.  In the named directory hash table, this means
       that `value' may be referred to as `~name'.

       For each name with no corresponding value, attempt to  add  name
       to the hash table, checking what the appropriate value is in the
       normal manner for that hash  table.   If  an  appropriate  value
       can't be found, then the hash table will be unchanged.

       The -v option causes hash table entries to be listed as they are
       added by explicit specification.  If has no effect if used  with
       -f.

       If the -L flag is present, then each hash table entry is printed
       in the form of a call to hash.

rehash Same as hash -r.
