What is eif?

What doesn't eif do?

Autoconnection

would be equivalent to

from the eif command prompt.

When the last line in the .eifrc file is:

an autoconnect function is served.

Runtime Options

Command Level

"$var"s are replaced with the value of the variable "var". See below.

Leading spaces on a command line are ignored, and not sent to empire.

Multiple commands may be entered on the same line, with the commands seperated by a ";" character. IE, "nation ; power" will perform a nation, then a power command. ";"s inside of quoted strings (") are ignored for this.

(NOTE that ";" will not seperate lines inside of telegrams and announcements. Otherwise you can't get ";" into them. Not sure if this is proper, but....)

Output is redirected using ">".

>fname

direct this command's output into the file "fname". File must NOT exist. Command aborted if it does.

>>fname

this command's output is appended to the file "fname". The file may or may not exist.

>!fname

this command's output written to the file "fname". Any existing data in the file is wiped.

Piping is supported, through the "|" type syntax.

Aliases are supported. If the first non-space string on a command line matches an alias, the string is replaced with the alias. NOTE that string in this context can have any characters but spaces, not withstanding any other special characters. (#,&,!!,^)

Command history is supported.

^p

moves backwards in command history.

^n

moves forewards in command history.

!!

repeat last command.

!str

repeat last command which started with "str".

!?str?

repeat last command which contained "str".

!n

repeat the nth command, where n is a number.

!-n

repeat the nth previous command, where n is a number.

^s1^s2

repeat the previous command, replacing string s1 with string s2.

Secondary Input

This creates problems for exec files, aliases, etc, since you are not always sure how many questions will be asked. Thus, you can mark secondary input lines with a leading "&". This prevents the secondary input lines as being attempted as commands.

IE, "read >>read ; &y ; &n" will avoid that annoying problem of telegrams arriving while reading.

And, "build plane 16,2 ; &fighter 2 ; & " fixed the problem of not being able to specify multiword entries in a single line. (Typing "build plane 16,2 fighter 2 100" would try to build you a 'fighter 1' at tech 2.) This example is outdated now.

Preconditioning:

leading spaces are removed.

Spaces after the "&", as well as the "&", are removed.

trailing spaces are removed.

("ssm 2 " is not == "ssm 2".)

This preconditioning is not done for telegrams and announcements, through a special case which examines the prompt string.

Escaping

Aliases

'alias'

list all the aliases

'alias word'

show what alias 'word' is.

'alias word command'

create/change alias 'word' to command.

'alias word "command"'

ditto, but the "s are removed. Allows embedding of several commands inside one alias. ie, 'alias dd "dump #0 >!dmp; map #0 >!map"'

'unalias word'

delete the alias for 'word', if it exists.

The variables $0, $1, $2, ... are supported for aliases. They are the "words" in the command that the alias is working on.

Also, these variables can be conditional.

${N:-word}

uses "word" if argument N does not exist.

${N:?word}

prints out "word" and aborts command if N does not exist.

${N:+word}

uses nothing if argument N does not exist.

"words" are space delimited, or surrounded by "s.

Example:

Exec

exec filename

execute the commands in "filename".

exec's are allowed to be recursive, but at this time there is a minor bug when the exec file ends on secondary input. Input is redirected to stdin, and not the calling exec file. Fixed some day.

Output redirection handles recursive execs.

Variables

$$

process id.

$<

read from stdinput.

${}

a literal $.

${<:%word}

read from stdinput, using "word" as a prompt.

$%name

retrieve "name" from the runtime environment, using getenv().

$name

replace with value of "name".

${name}

replace with value of name.

${name:-word}

if name is not set, or null, use "word" instead.

${name:=word}

if name is not set, or null, use "word", and set variable to "word".

${name:?word}

if name not set, or null, print "word" and abort command.

${name:+word}

if name not set, or null, substitute nothing.

${name:%word}

use "word" as prompt if "name" == "<". ":%word" ignored elsewhere.

setvar name string

 

setvar name "string"

 

setvar name

 

unsetvar name

 

If %name is used instead of name as first argument to either setvar or unsetvar, the environment is used instead of eif's local variable scope.

Commands

alias

setting aliases.

unalias

remove an alias.

echo

print out the rest of the line.

beep

make a beep.

games

show the games that are configure in.

addgame

add a game.

connect

connect to a game.

kill

kill a hung game process. (Only works if server supports it.)

try

try a country/rep at a given game.

trykill

kill a hung game process for a country/rep at a given game.

exit

quit the program

cmdlist

list these commands

exec

execute a file. Supports ~/filename.

runfeed

execute a program, and use its output as eif commands.

history

display a listing of the command history.

setvar

set a variable.

unsetvar

delete a variable.

@

pass the rest of the command off to the system to execute.

if

Uses /bin/test, and stops at endif. Disables command if test returns false. Can be nested. Cannot span exec files.

elseif

Next case in an if sequence, same testing as 'if'.

else

Last case in an if sequence.

endif

Ends an 'if' sequence.

The file "$HOME/.eifrc" is read in and executed as an exec file.

Other Things

Example .eifrc

# Games
addgame cvis blitz.wolfpackempire.com 6789 visitor visitor .empire.chg
addgame zvis blitz.wolfpackempire.com 5678 visitor visitor .empire.zeb

# Read system eifrc
exec /usr/local/lib/eif/eifrc.include

# Prevent name clashes by defining abbreviations ourselves
alias	ex	"expl c ${1} 1"
alias	pl	plane
alias	sh	ship
alias	m	map
alias	b	bmap
alias	sh	ship
alias	x	exit
alias	c	connect

# Run the sat command on all planes in wing S (see eifrc.include)
alias	sats	"pwith S do sat \[\]"

# If a game was passed as argument, connect to it.
conn ${AUTOGAME:?}