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 / or with a relative path start-
       ing with ./ or ../ is never executed by lookup  in  the  command
       hash table, and these can only be added to the table by explicit
       use  of the hash command.  Such a command is always found by di-
       rect 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  (and  only)
       the  absolute  directories in the PATH, and for the named direc-
       tory hash table this adds all users'  home  directories.   These
       two options cannot be used with any arguments.  Both options re-
       move any explicitly-added elements.

       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.
