Unknown option: "-3" Unix manual page for unsetenv. (host=minya system=Darwin)
BUILTIN(1)                BSD General Commands Manual               BUILTIN(1)

NAME
     builtin, !, %, ., :, @, {, }, alias, alloc, bg, bind, bindkey, break,
     breaksw, builtins, case, cd, chdir, command, complete, continue, default,
     dirs, do, done, echo, echotc, elif, else, end, endif, endsw, esac, eval,
     exec, exit, export, false, fc, fg, filetest, fi, for, foreach, getopts,
     glob, goto, hash, hashstat, history, hup, if, jobid, jobs, kill, limit,
     local, log, login, logout, ls-F, nice, nohup, notify, onintr, popd,
     printenv, pushd, pwd, read, readonly, rehash, repeat, return, sched, set,
     setenv, settc, setty, setvar, shift, source, stop, suspend, switch,
     telltc, test, then, time, times, trap, true, type, ulimit, umask,
     unalias, uncomplete, unhash, unlimit, unset, unsetenv, until, wait,
     where, which, while -- shell built-in commands

SYNOPSIS
     builtin [-options] [args ...]

DESCRIPTION
     Shell builtin commands are commands that can be executed within the run-
     ning shell's process.  Note that, in the case of csh(1) builtin commands,
     the command is executed in a subshell if it occurs as any component of a
     pipeline except the last.

     If a command specified to the shell contains a slash ``/'', the shell
     will not execute a builtin command, even if the last component of the
     specified command matches the name of a builtin command.  Thus, while
     specifying ``echo'' causes a builtin command to be executed under shells
     that support the echo builtin command, specifying ``/bin/echo'' or
     ``./echo'' does not.

     While some builtin commands may exist in more than one shell, their oper-
     ation may be different under each shell which supports them.  Below is a
     table which lists shell builtin commands, the standard shells that sup-
     port them and whether they exist as standalone utilities.

     Only builtin commands for the csh(1) and sh(1) shells are listed here.
     Consult a shell's manual page for details on the operation of its builtin
     commands.  Beware that the sh(1) manual page, at least, calls some of
     these commands ``built-in commands'' and some of them ``reserved words''.
     Users of other shells may need to consult an info(1) page or other
     sources of documentation.

     Commands marked ``No**'' under External do exist externally, but are
     implemented as scripts using a builtin command of the same name.

           Command External    csh(1)    sh(1)
           !             No          No        Yes
           %             No          Yes       No
           .             No          No        Yes
           :             No          Yes       Yes
           @             No          Yes       Yes
           {             No          No        Yes
           }             No          No        Yes
           alias         No**        Yes       Yes
           alloc         No          Yes       No
           bg            No**        Yes       Yes
           bind          No          No        Yes
           bindkey       No          Yes       No
           break         No          Yes       Yes
           breaksw       No          Yes       No
           builtin       No          No        Yes
           builtins      No          Yes       No
           case          No          Yes       Yes
           cd            No**        Yes       Yes
           chdir         No          Yes       Yes
           command       No**        No        Yes
           complete      No          Yes       No
           continue      No          Yes       Yes
           default       No          Yes       No
           dirs          No          Yes       No
           do            No          No        Yes
           done          No          No        Yes
           echo          Yes         Yes       Yes
           echotc        No          Yes       No
           elif          No          No        Yes
           else          No          Yes       Yes
           end           No          Yes       No
           endif         No          Yes       No
           endsw         No          Yes       No
           esac          No          No        Yes
           eval          No          Yes       Yes
           exec          No          Yes       Yes
           exit          No          Yes       Yes
           export        No          No        Yes
           false         Yes         No        Yes
           fc            No**        No        Yes
           fg            No**        Yes       Yes
           filetest      No          Yes       No
           fi            No          No        Yes
           for           No          No        Yes
           foreach       No          Yes       No
           getopts       No**        No        Yes
           glob          No          Yes       No
           goto          No          Yes       No
           hash          No          No        Yes
           hashstat      No          Yes       No
           history       No          Yes       No
           hup           No          Yes       No
           if            No          Yes       Yes
           jobid         No          No        Yes
           jobs          No**        Yes       Yes
           kill          Yes         Yes       No
           limit         No          Yes       No
           local         No          No        Yes
           log           No          Yes       No
           login         Yes         Yes       No
           logout        No          Yes       No
           ls-F          No          Yes       No
           nice          Yes         Yes       No
           nohup         Yes         Yes       No
           notify        No          Yes       No
           onintr        No          Yes       No
           popd          No          Yes       No
           printenv      Yes         Yes       No
           pushd         No          Yes       No
           pwd           Yes         No        Yes
           read          No**        No        Yes
           readonly      No          No        Yes
           rehash        No          Yes       No
           repeat        No          Yes       No
           return        No          No        Yes
           sched         No          Yes       No
           set           No          Yes       Yes
           setenv        No          Yes       No
           settc         No          Yes       No
           setty         No          Yes       No
           setvar        No          No        Yes
           shift         No          Yes       Yes
           source        No          Yes       No
           stop          No          Yes       No
           suspend       No          Yes       No
           switch        No          Yes       No
           telltc        No          Yes       No
           test          Yes         No        Yes
           then          No          No        Yes
           time          Yes         Yes       No
           times         No          No        Yes
           trap          No          No        Yes
           true          Yes         No        Yes
           type          No          No        Yes
           ulimit        No          No        Yes
           umask         No**        Yes       Yes
           unalias       No**        Yes       Yes
           uncomplete    No          Yes       No
           unhash        No          Yes       No
           unlimit       No          Yes       No
           unset         No          Yes       Yes
           unsetenv      No          Yes       No
           until         No          No        Yes
           wait          No**        Yes       Yes
           where         No          Yes       No
           which         Yes         Yes       No
           while         No          Yes       Yes

SEE ALSO
     csh(1), echo(1), false(1), info(1), kill(1), login(1), nice(1), nohup(1),
     printenv(1), pwd(1), sh(1), test(1), time(1), true(1), which(1)

HISTORY
     The builtin manual page first appeared in FreeBSD 3.4.

AUTHORS
     This manual page was written by Sheldon Hearn <sheldonh@FreeBSD.org>.

BSD                            February 23, 2005                           BSD