.TH Concept "Command Syntax"
.NA Syntax "The Empire command syntax"
.LV Basic
.de AB
.in 0.3i
.ti -0.3i
..
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The Empire Shell (command interpreter)
expects input in the form:
.EX VERB ARG1 ARG2 ...
VERB is any one of the Empire commands on the \*Qcommand list\*U
(what you see when you type \*Qlist\*U-- e.g. 
\*Qmap\*U, \*Qmove\*U, \*Qinfo\*U, etc).
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The number of ARGs varies from command to command.
In most cases the ARGs need not be supplied on the command line;
any that are not supplied will be obtained by prompting.
The exception to this rule are those ARGs
that are enclosed in [square brackets]
in the command list.
The presence of these ARGs changes the way the command is carried out.
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Certain basic argument types recur often and are abbreviated in the
following ways.
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.AB
<TYPE> ::= 'se', 'sh', 'l', or 'p' for sector, ship, land unit, or
plane respectively.  If "sector" is not a possibility, then 's' will
likely suffice for "ship".
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.AB
<CNUM/CNAME> ::= either a country number or a country name
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.AB
<COMM> ::= any one, (or unambiguous abbreviation), of the list of
commodities found in \*Qinfo Selector\*U:
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.AB
<LOAN> ::= loan number
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.AB
<SECT> ::= sector coordinates in the form: x,y
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.AB
.ne 4
<SECTS> ::= sector(s) in the form:
.NF
lox:hix,loy:hiy ?cond&cond&...
.FI
\*Qlox\*U, \*Qhix\*U, \*Qloy\*U, \*Qhiy\*U are coordinates bounding
the rectangular area to be considered
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\*Qcond\*U is a condition of the form:
.NF
<VALUE><OPERATOR><VALUE>
.FI
<VALUE> is either a <COMM>, as above,
a number in the range 0 to 65536,
a sector designation,
(\*Qm\*U for mine, \*Qc\*U for capital, etc), a type of unit
(\*Qfrigate\*U, \*Qcavalry\*U, etc), or a selector found in \*Qinfo
Selector\*U.
.br
<OPERATOR> can be any one of:
.in +\w'#\0\0'u
.L <
less than
.L =
equal
.L >
greater than
.L #
not equal
.in
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Thus \*Qmob=100\*U, \*Qore#0\*U, \*Q7=guns\*U, \*Qciv#mil\*U,
\*Qdes=b\*U are examples of legitimate conditions,
(note lack of embedded spaces),
and
.EX census -3:3,-3:3 ?des=+&gun=5&mil>civ
will list all highways
within 3 of your capital
with exactly 5 guns and more military than civilians.
.sp
Similarly,
.EX deliver f -9:9,-9:9 ?f_del=0
will allow you to set up food delivery
in all the sectors that don't already
have food delivery.
.sp
Note that \*Qhix\*U, \*Qhiy\*U, and \*Q?cond\*U are all optional.
Also, the entire \*Qlox:hix,loy:hiy\*U section may be replaced
by either \*Q#\*U, \*Q#0\*U, \*Q#1\*U, \*Q#2\*U,
or \*Q#3\*U, ... which refer to 
\*Qrealm\*Us which you can define.
(See \*Qinfo realm\*U.)
Note that \*Q#\*U and \*Q#0\*U are equivalent.  Also \*Q*\*U refers to
all sectors, and \*Q@x,y:dist\*U refers to all sectors within dist of x,y.
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.AB
<SHIP> ::= one ship number
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.AB
<FLEET> ::= fleet designation,
which may be a list of ships separated by slashes (`/'),
a fleet letter,
the character tilde (`~') which means all ships not in a specific fleet,
or a rectangular sector area.
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.AB
<SHIP/FLEET> ::= either a single ship number or a fleet designation.
.sp
Note that <FLEET> specifications may have an optional ?cond&cond...
argument like that used for <SECTS> arguments.
For instance:
.EX ship ~ ?des=d&mil>5
will list all destroyers that have more than 5 military
which are not currently in any fleet.
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The output from commands may also be sent to a file or another
process by utilizing these alternate syntaxes:
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.ne 2
.EX VERB ARG1 ... > FILE
which sends the output to the file \*QFILE\*U.
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.ne 2
.EX VERB ARG1 ... >> FILE
which appends the output to the file \*QFILE\*U.
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.ne 2
.EX VERB ARG1 ... >! FILE
which sends the output to the file \*QFILE\*U,
replacing the file it if it already exists.
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.ne 2
.EX VERB ARG ... | PROGRAM [ARGS...]
which send the output of the command to the program \*QPROGRAM\*U
with optional arguments \*QARGS\*U.
This is most useful when \*QPROGRAM\*U is some type of
pager like \*(iFmore\*(pF(1) or \*(iFless\*(pF(1).
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The Empire shell also recognizes a few control characters:
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.in +\w'interrupt\0\0'u
.L \fIname\fP
\fImeaning\fP
.L interrupt
Abort command and return to Empire command level
.L quit
Exit Empire
.L EOT
Exit Empire
.in
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.SA "realm, Move, Selector, Playing"