DragonFly On-Line Manual Pages
BUILTIN(1) DragonFly 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, let,
limit, local, log, login, logout, ls-F, nice, nohup, notify, onintr,
popd, printenv, printf, pushd, pwd, read, readonly, rehash, repeat,
return, sched, set, setenv, settc, setty, setvar, shift, source, stop,
suspend, switch, telltc, termname, test, then, time, times, trap, true,
type, ulimit, umask, unalias, uncomplete, unhash, unlimit, unset,
unsetenv, until, wait, where, which, while, wordexp, wordexp2 - shell
built-in commands
SYNOPSIS
See the built-in command description in the appropriate shell manual
page.
DESCRIPTION
Shell builtin commands are commands that can be executed within the
running 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
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)
! No No Yes
% No Yes No
. No No Yes
: No Yes Yes
@ No Yes No
[ Yes No 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 Yes
let No No Yes
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
printf Yes No Yes
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
termname 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
wordexp No No Yes
wordexp2 No No Yes
Note that the wordexp and wordexp2 commands are only meant to be used by
wordexp(3) and not by the user.
SEE ALSO
csh(1), echo(1), false(1), info(1), kill(1), login(1), nice(1), nohup(1),
printenv(1), printf(1), pwd(1), sh(1), test(1), time(1), true(1),
which(1), wordexp(3)
HISTORY
The builtin manual page first appeared in FreeBSD 3.4.
AUTHORS
This manual page was written by Sheldon Hearn <sheldonh@FreeBSD.org>.
DragonFly 5.9-DEVELOPMENT October 9, 2020 DragonFly 5.9-DEVELOPMENT
foreach(n) Tcl Built-In Commands foreach(n)
______________________________________________________________________________
NAME
foreach - Iterate over all elements in one or more lists
SYNOPSIS
foreach varname list body
foreach varlist1 list1 ?varlist2 list2 ...? body
______________________________________________________________________________
DESCRIPTION
The foreach command implements a loop where the loop variable(s) take
on values from one or more lists. In the simplest case there is one
loop variable, varname, and one list, list, that is a list of values to
assign to varname. The body argument is a Tcl script. For each
element of list (in order from first to last), foreach assigns the
contents of the element to varname as if the lindex command had been
used to extract the element, then calls the Tcl interpreter to execute
body.
In the general case there can be more than one value list (e.g., list1
and list2), and each value list can be associated with a list of loop
variables (e.g., varlist1 and varlist2). During each iteration of the
loop the variables of each varlist are assigned consecutive values from
the corresponding list. Values in each list are used in order from
first to last, and each value is used exactly once. The total number
of loop iterations is large enough to use up all the values from all
the value lists. If a value list does not contain enough elements for
each of its loop variables in each iteration, empty values are used for
the missing elements.
The break and continue statements may be invoked inside body, with the
same effect as in the for command. Foreach returns an empty string.
EXAMPLES
This loop prints every value in a list together with the square and
cube of the value:
set values {1 3 5 7 2 4 6 8} ;# Odd numbers first, for fun!
puts "Value\tSquare\tCube" ;# Neat-looking header
foreach x $values { ;# Now loop and print...
puts " $x\t [expr {$x**2}]\t [expr {$x**3}]"
}
The following loop uses i and j as loop variables to iterate over pairs
of elements of a single list.
set x {}
foreach {i j} {a b c d e f} {
lappend x $j $i
}
# The value of x is "b a d c f e"
# There are 3 iterations of the loop.
The next loop uses i and j to iterate over two lists in parallel.
set x {}
foreach i {a b c} j {d e f g} {
lappend x $i $j
}
# The value of x is "a d b e c f {} g"
# There are 4 iterations of the loop.
The two forms are combined in the following example.
set x {}
foreach i {a b c} {j k} {d e f g} {
lappend x $i $j $k
}
# The value of x is "a d e b f g c {} {}"
# There are 3 iterations of the loop.
SEE ALSO
for(n), while(n), break(n), continue(n)
KEYWORDS
foreach, iteration, list, loop
Tcl foreach(n)