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
new_pair(3X) new_pair(3X)
NAME
alloc_pair, find_pair, free_pair - new curses color-pair functions
SYNOPSIS
#include <ncurses/curses.h>
int alloc_pair(int fg, int bg);
int find_pair(int fg, int bg);
int free_pair(int pair);
DESCRIPTION
These functions are an extension to the curses library. They permit an
application to dynamically allocate a color pair using the
foreground/background colors rather than assign a fixed color pair
number, and return an unused pair to the pool.
The number of colors may be related to the number of possible color
pairs for a given terminal, or it may not:
o While almost all terminals allow setting the color attributes
independently, it is unlikely that your terminal allows you to
modify the attributes of a given character cell without rewriting
it. That is, the foreground and background colors are applied as a
pair.
o Color pairs are the curses library's way of managing a color
palette on a terminal. If the library does not keep track of the
combinations of colors which are displayed, it will be inefficient.
o For simple terminal emulators with only a few dozen color
combinations, it is convenient to use the maximum number of
combinations as the limit on color pairs:
COLORS * COLORS
o Terminals which support default colors distinct from "ANSI colors"
add to the possible combinations, producing this total:
( COLORS + 1 ) * ( COLORS + 1 )
o An application might use up to a few dozen color pairs to implement
a predefined color scheme.
Beyond that lies in the realm of programs using the foreground and
background colors for "ASCII art" (or some other non-textual
application).
Also beyond those few dozen pairs, the required size for a table to
represent the combinations grows rapidly with an increasing number
of colors.
These functions allow a developer to let the screen library manage
color pairs.
alloc_pair
The alloc_pair function accepts parameters for foreground and
background color, and checks if that color combination is already
associated with a color pair.
o If the combination already exists, alloc_pair returns the existing
pair.
o If the combination does not exist, alloc_pair allocates a new color
pair and returns that.
o If the table fills up, alloc_pair discards the least-recently
allocated entry using free_pair and allocates a new color pair.
All of the color pairs are allocated from a table of possible color
pairs. The size of the table is determined by the terminfo pairs
capability. The table is shared with init_pair; in fact alloc_pair
calls init_pair after updating the ncurses library's fast index to the
colors versus color pairs.
find_pair
The find_pair function accepts parameters for foreground and background
color, and checks if that color combination is already associated with
a color pair, returning the pair number if it has been allocated.
Otherwise it returns -1.
free_pair
Marks the given color pair as unused, i.e., like color pair 0.
RETURN VALUE
The alloc_pair function returns a color pair number in the range 1
through COLOR_PAIRS-1, unless it encounters an error updating its fast
index to the color pair values, preventing it from allocating a color
pair. In that case, it returns -1.
The find_pair function returns a color pair number if the given color
combination has been associated with a color pair, or -1 if not.
Likewise, free_pair returns OK unless it encounters an error updating
the fast index or if no such color pair is in use.
PORTABILITY
These routines are specific to ncurses. They were not supported on
Version 7, BSD or System V implementations. It is recommended that any
code depending on them be conditioned using NCURSES_VERSION.
SEE ALSO
curs_color(3X).
AUTHOR
Thomas Dickey.
new_pair(3X)