Manual Pages  — BUILTIN

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 operation may be different under each shell which supports them. Below is a table which lists shell builtin commands, the standard shells that support 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 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)
amp;!	amp;No	amp;No	Yes
%	amp;No	Yes	amp;No
amp;.	amp;No	amp;No	Yes
amp;:	amp;No	Yes	Yes
@	amp;No	Yes	amp;No
amp;[	Yes	amp;No	Yes
{	amp;No	amp;No	Yes
}	amp;No	amp;No	Yes
alias	No**	Yes	Yes
alloc	amp;No	Yes	amp;No
bg	No**	Yes	Yes
bind	amp;No	amp;No	Yes
bindkey	amp;No	Yes	amp;No
break	amp;No	Yes	Yes
breaksw	amp;No	Yes	amp;No
builtin	amp;No	amp;No	Yes
builtins	amp;No	Yes	amp;No
case	amp;No	Yes	Yes
cd	No**	Yes	Yes
chdir	amp;No	Yes	Yes
command	No**	amp;No	Yes
complete	amp;No	Yes	amp;No
continue	amp;No	Yes	Yes
default	amp;No	Yes	amp;No
dirs	amp;No	Yes	amp;No
do	amp;No	amp;No	Yes
done	amp;No	amp;No	Yes
echo	Yes	Yes	Yes
echotc	amp;No	Yes	amp;No
elif	amp;No	amp;No	Yes
else	amp;No	Yes	Yes
end	amp;No	Yes	amp;No
endif	amp;No	Yes	amp;No
endsw	amp;No	Yes	amp;No
esac	amp;No	amp;No	Yes
eval	amp;No	Yes	Yes
exec	amp;No	Yes	Yes
exit	amp;No	Yes	Yes
export	amp;No	amp;No	Yes
false	Yes	amp;No	Yes
fc	No**	amp;No	Yes
fg	No**	Yes	Yes
filetest	amp;No	Yes	amp;No
fi	amp;No	amp;No	Yes
for	amp;No	amp;No	Yes
foreach	amp;No	Yes	amp;No
getopts	No**	amp;No	Yes
glob	amp;No	Yes	amp;No
goto	amp;No	Yes	amp;No
hash	No**	amp;No	Yes
hashstat	amp;No	Yes	amp;No
history	amp;No	Yes	amp;No
hup	amp;No	Yes	amp;No
if	amp;No	Yes	Yes
jobid	amp;No	amp;No	Yes
jobs	No**	Yes	Yes
kill	Yes	Yes	Yes
limit	amp;No	Yes	amp;No
local	amp;No	amp;No	Yes
log	amp;No	Yes	amp;No
login	Yes	Yes	amp;No
logout	amp;No	Yes	amp;No
ls-F	amp;No	Yes	amp;No
nice	Yes	Yes	amp;No
nohup	Yes	Yes	amp;No
notify	amp;No	Yes	amp;No
onintr	amp;No	Yes	amp;No
popd	amp;No	Yes	amp;No
printenv	Yes	Yes	amp;No
printf	Yes	amp;No	Yes
pushd	amp;No	Yes	amp;No
pwd	Yes	amp;No	Yes
read	No**	amp;No	Yes
readonly	amp;No	amp;No	Yes
rehash	amp;No	Yes	amp;No
repeat	amp;No	Yes	amp;No
return	amp;No	amp;No	Yes
sched	amp;No	Yes	amp;No
set	amp;No	Yes	Yes
setenv	amp;No	Yes	amp;No
settc	amp;No	Yes	amp;No
setty	amp;No	Yes	amp;No
setvar	amp;No	amp;No	Yes
shift	amp;No	Yes	Yes
source	amp;No	Yes	amp;No
stop	amp;No	Yes	amp;No
suspend	amp;No	Yes	amp;No
switch	amp;No	Yes	amp;No
telltc	amp;No	Yes	amp;No
test	Yes	amp;No	Yes
then	amp;No	amp;No	Yes
time	Yes	Yes	amp;No
times	amp;No	amp;No	Yes
trap	amp;No	amp;No	Yes
true	Yes	amp;No	Yes
type	No**	amp;No	Yes
ulimit	No**	amp;No	Yes
umask	No**	Yes	Yes
unalias	No**	Yes	Yes
uncomplete	amp;No	Yes	amp;No
unhash	amp;No	Yes	amp;No
unlimit	amp;No	Yes	amp;No
unset	amp;No	Yes	Yes
unsetenv	amp;No	Yes	amp;No
until	amp;No	amp;No	Yes
wait	No**	Yes	Yes
where	amp;No	Yes	amp;No
which	Yes	Yes	amp;No
while	amp;No	Yes	Yes