Shell built-in commands

1.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.

2.shell built-in commands:

     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