freebsd-skq/share/man/man1/builtin.1
jilles ae2aabc349 sh: Add kill builtin.
This allows specifying a %job (which is equivalent to the corresponding
process group).

Additionally, it improves reliability of kill from sh in high-load
situations and ensures "kill" finds the correct utility regardless of PATH,
as required by POSIX (unless the undocumented %builtin mechanism is used).

Side effect: fatal errors (any error other than kill(2) failure) now return
exit status 2 instead of 1. (This is consistent with other sh builtins, but
not in NetBSD.)

Code size increases about 1K on i386.

Obtained from:	NetBSD
2010-12-21 22:47:34 +00:00

333 lines
8.5 KiB
Groff

.\"
.\" Copyright (c) 1999 Sheldon Hearn
.\"
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd December 21, 2010
.Dt BUILTIN 1
.Os
.Sh NAME
.Nm builtin ,
.Nm \&! ,
.Nm % ,
.Nm \&. ,
.Nm \&: ,
.Nm @ ,
.Nm \&[ ,
.Nm { ,
.Nm } ,
.Nm alias ,
.Nm alloc ,
.Nm bg ,
.Nm bind ,
.Nm bindkey ,
.Nm break ,
.Nm breaksw ,
.Nm builtins ,
.Nm case ,
.Nm cd ,
.Nm chdir ,
.Nm command ,
.Nm complete ,
.Nm continue ,
.Nm default ,
.Nm dirs ,
.Nm do ,
.Nm done ,
.Nm echo ,
.Nm echotc ,
.Nm elif ,
.Nm else ,
.Nm end ,
.Nm endif ,
.Nm endsw ,
.Nm esac ,
.Nm eval ,
.Nm exec ,
.Nm exit ,
.Nm export ,
.Nm false ,
.Nm fc ,
.Nm fg ,
.Nm filetest ,
.Nm fi ,
.Nm for ,
.Nm foreach ,
.Nm getopts ,
.Nm glob ,
.Nm goto ,
.Nm hash ,
.Nm hashstat ,
.Nm history ,
.Nm hup ,
.Nm if ,
.Nm jobid ,
.Nm jobs ,
.Nm kill ,
.Nm limit ,
.Nm local ,
.Nm log ,
.Nm login ,
.Nm logout ,
.Nm ls-F ,
.Nm nice ,
.Nm nohup ,
.Nm notify ,
.Nm onintr ,
.Nm popd ,
.Nm printenv ,
.Nm printf ,
.Nm pushd ,
.Nm pwd ,
.Nm read ,
.Nm readonly ,
.Nm rehash ,
.Nm repeat ,
.Nm return ,
.Nm sched ,
.Nm set ,
.Nm setenv ,
.Nm settc ,
.Nm setty ,
.Nm setvar ,
.Nm shift ,
.Nm source ,
.Nm stop ,
.Nm suspend ,
.Nm switch ,
.Nm telltc ,
.Nm test ,
.Nm then ,
.Nm time ,
.Nm times ,
.Nm trap ,
.Nm true ,
.Nm type ,
.Nm ulimit ,
.Nm umask ,
.Nm unalias ,
.Nm uncomplete ,
.Nm unhash ,
.Nm unlimit ,
.Nm unset ,
.Nm unsetenv ,
.Nm until ,
.Nm wait ,
.Nm where ,
.Nm which ,
.Nm while
.Nd shell built-in commands
.Sh SYNOPSIS
See the built-in command description in the appropriate shell manual page.
.Sh DESCRIPTION
Shell builtin commands are commands that can be executed within the
running shell's process.
Note that, in the case of
.Xr csh 1
builtin commands, the command is executed in a subshell if it occurs as
any component of a pipeline except the last.
.Pp
If a command specified to the shell contains a slash
.Ql / ,
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
.Dq Li echo
causes a builtin command to be executed under shells that support the
.Nm echo
builtin command,
specifying
.Dq Li /bin/echo
or
.Dq Li ./echo
does not.
.Pp
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.
.Pp
Only builtin commands for the
.Xr csh 1
and
.Xr sh 1
shells are listed here.
Consult a shell's manual page for
details on the operation its builtin commands.
Beware that the
.Xr sh 1
manual page, at least, calls some of these commands
.Dq built-in commands
and some of them
.Dq reserved words .
Users of other shells may need to consult an
.Xr info 1
page or other sources of documentation.
.Pp
Commands marked
.Dq Li No**
under
.Em External
do exist externally,
but are implemented as scripts using a builtin command of the same name.
.Bl -column ".Ic uncomplete" ".Em External" ".Xr csh 1" ".Xr sh 1" -offset indent
.It Em Command Ta Em External Ta Xr csh 1 Ta Xr sh 1
.It Ic \&! Ta \&No Ta \&No Ta Yes
.It Ic % Ta \&No Ta Yes Ta \&No
.It Ic \&. Ta \&No Ta \&No Ta Yes
.It Ic \&: Ta \&No Ta Yes Ta Yes
.It Ic @ Ta \&No Ta Yes Ta \&No
.It Ic \&[ Ta Yes Ta \&No Ta Yes
.It Ic { Ta \&No Ta \&No Ta Yes
.It Ic } Ta \&No Ta \&No Ta Yes
.It Ic alias Ta No** Ta Yes Ta Yes
.It Ic alloc Ta \&No Ta Yes Ta \&No
.It Ic bg Ta No** Ta Yes Ta Yes
.It Ic bind Ta \&No Ta \&No Ta Yes
.It Ic bindkey Ta \&No Ta Yes Ta \&No
.It Ic break Ta \&No Ta Yes Ta Yes
.It Ic breaksw Ta \&No Ta Yes Ta \&No
.It Ic builtin Ta \&No Ta \&No Ta Yes
.It Ic builtins Ta \&No Ta Yes Ta \&No
.It Ic case Ta \&No Ta Yes Ta Yes
.It Ic cd Ta No** Ta Yes Ta Yes
.It Ic chdir Ta \&No Ta Yes Ta Yes
.It Ic command Ta No** Ta \&No Ta Yes
.It Ic complete Ta \&No Ta Yes Ta \&No
.It Ic continue Ta \&No Ta Yes Ta Yes
.It Ic default Ta \&No Ta Yes Ta \&No
.It Ic dirs Ta \&No Ta Yes Ta \&No
.It Ic do Ta \&No Ta \&No Ta Yes
.It Ic done Ta \&No Ta \&No Ta Yes
.It Ic echo Ta Yes Ta Yes Ta Yes
.It Ic echotc Ta \&No Ta Yes Ta \&No
.It Ic elif Ta \&No Ta \&No Ta Yes
.It Ic else Ta \&No Ta Yes Ta Yes
.It Ic end Ta \&No Ta Yes Ta \&No
.It Ic endif Ta \&No Ta Yes Ta \&No
.It Ic endsw Ta \&No Ta Yes Ta \&No
.It Ic esac Ta \&No Ta \&No Ta Yes
.It Ic eval Ta \&No Ta Yes Ta Yes
.It Ic exec Ta \&No Ta Yes Ta Yes
.It Ic exit Ta \&No Ta Yes Ta Yes
.It Ic export Ta \&No Ta \&No Ta Yes
.It Ic false Ta Yes Ta \&No Ta Yes
.It Ic fc Ta No** Ta \&No Ta Yes
.It Ic fg Ta No** Ta Yes Ta Yes
.It Ic filetest Ta \&No Ta Yes Ta \&No
.It Ic fi Ta \&No Ta \&No Ta Yes
.It Ic for Ta \&No Ta \&No Ta Yes
.It Ic foreach Ta \&No Ta Yes Ta \&No
.It Ic getopts Ta No** Ta \&No Ta Yes
.It Ic glob Ta \&No Ta Yes Ta \&No
.It Ic goto Ta \&No Ta Yes Ta \&No
.It Ic hash Ta No** Ta \&No Ta Yes
.It Ic hashstat Ta \&No Ta Yes Ta \&No
.It Ic history Ta \&No Ta Yes Ta \&No
.It Ic hup Ta \&No Ta Yes Ta \&No
.It Ic if Ta \&No Ta Yes Ta Yes
.It Ic jobid Ta \&No Ta \&No Ta Yes
.It Ic jobs Ta No** Ta Yes Ta Yes
.It Ic kill Ta Yes Ta Yes Ta Yes
.It Ic limit Ta \&No Ta Yes Ta \&No
.It Ic local Ta \&No Ta \&No Ta Yes
.It Ic log Ta \&No Ta Yes Ta \&No
.It Ic login Ta Yes Ta Yes Ta \&No
.It Ic logout Ta \&No Ta Yes Ta \&No
.It Ic ls-F Ta \&No Ta Yes Ta \&No
.It Ic nice Ta Yes Ta Yes Ta \&No
.It Ic nohup Ta Yes Ta Yes Ta \&No
.It Ic notify Ta \&No Ta Yes Ta \&No
.It Ic onintr Ta \&No Ta Yes Ta \&No
.It Ic popd Ta \&No Ta Yes Ta \&No
.It Ic printenv Ta Yes Ta Yes Ta \&No
.It Ic printf Ta Yes Ta \&No Ta Yes
.It Ic pushd Ta \&No Ta Yes Ta \&No
.It Ic pwd Ta Yes Ta \&No Ta Yes
.It Ic read Ta No** Ta \&No Ta Yes
.It Ic readonly Ta \&No Ta \&No Ta Yes
.It Ic rehash Ta \&No Ta Yes Ta \&No
.It Ic repeat Ta \&No Ta Yes Ta \&No
.It Ic return Ta \&No Ta \&No Ta Yes
.It Ic sched Ta \&No Ta Yes Ta \&No
.It Ic set Ta \&No Ta Yes Ta Yes
.It Ic setenv Ta \&No Ta Yes Ta \&No
.It Ic settc Ta \&No Ta Yes Ta \&No
.It Ic setty Ta \&No Ta Yes Ta \&No
.It Ic setvar Ta \&No Ta \&No Ta Yes
.It Ic shift Ta \&No Ta Yes Ta Yes
.It Ic source Ta \&No Ta Yes Ta \&No
.It Ic stop Ta \&No Ta Yes Ta \&No
.It Ic suspend Ta \&No Ta Yes Ta \&No
.It Ic switch Ta \&No Ta Yes Ta \&No
.It Ic telltc Ta \&No Ta Yes Ta \&No
.It Ic test Ta Yes Ta \&No Ta Yes
.It Ic then Ta \&No Ta \&No Ta Yes
.It Ic time Ta Yes Ta Yes Ta \&No
.It Ic times Ta \&No Ta \&No Ta Yes
.It Ic trap Ta \&No Ta \&No Ta Yes
.It Ic true Ta Yes Ta \&No Ta Yes
.It Ic type Ta No** Ta \&No Ta Yes
.It Ic ulimit Ta No** Ta \&No Ta Yes
.It Ic umask Ta No** Ta Yes Ta Yes
.It Ic unalias Ta No** Ta Yes Ta Yes
.It Ic uncomplete Ta \&No Ta Yes Ta \&No
.It Ic unhash Ta \&No Ta Yes Ta \&No
.It Ic unlimit Ta \&No Ta Yes Ta \&No
.It Ic unset Ta \&No Ta Yes Ta Yes
.It Ic unsetenv Ta \&No Ta Yes Ta \&No
.It Ic until Ta \&No Ta \&No Ta Yes
.It Ic wait Ta No** Ta Yes Ta Yes
.It Ic where Ta \&No Ta Yes Ta \&No
.It Ic which Ta Yes Ta Yes Ta \&No
.It Ic while Ta \&No Ta Yes Ta Yes
.El
.Sh SEE ALSO
.Xr csh 1 ,
.Xr echo 1 ,
.Xr false 1 ,
.Xr info 1 ,
.Xr kill 1 ,
.Xr login 1 ,
.Xr nice 1 ,
.Xr nohup 1 ,
.Xr printenv 1 ,
.Xr printf 1 ,
.Xr pwd 1 ,
.Xr sh 1 ,
.Xr test 1 ,
.Xr time 1 ,
.Xr true 1 ,
.Xr which 1
.Sh HISTORY
The
.Nm
manual page first appeared in
.Fx 3.4 .
.Sh AUTHORS
This manual page was written by
.An Sheldon Hearn Aq sheldonh@FreeBSD.org .