--- name: "comterp" section: "1" platform: "linux" package: "ivtools-bin" version: "2.0.11d.a1-3+b4" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/comterp" --- # comterp(1) distributed command interpreter demonstrator ## NAME comterp - distributed command interpreter demonstrator ## SYNOPSIS **comterp**\ **comterp** remote\ **comterp** server "portnum"\ **comterp** logger "portnum"\ **comterp** client "host" "portnum" \["file"\]\ **comterp** telcat "host" "portnum" \["file"\]\ **comterp** run "file" \ **comterp** "expr"\ ## DESCRIPTION comterp demonstrates the command interpreter incorporated into ivtools. A user (or client program) can interact with comterp via stdin and stdout or telnet (when ACE is built in). The command syntax is a semi-colon separated list of commands with arbitrary number of parameters enclosed in parenthesis, with support for optional parameters and keyword arguments, i.e: command2(arg1 arg2 arg3 :key1 val1 :key2 val2);\ command1(arg1 arg2 arg3 :key1 val1 :key2 val2) C-like binary expressions can be embedded anywhere in the command language, using the operators in the table below. Variables can be created on the fly with an assignment operator (i.e "ball=1" creates a integer "ball" variable set to 1). Unterminated expressions cause an automatic command line extension (until the parser determines the expression is complete). "(), "{}", and "\[\]" can all be used interchangeably. ## COMMAND OPTIONS comterp Invoke a single command interpreter to interact with via stdin and stdout. comterp remote Invoke a single command interpreter, like the default, and include a remote command for accessing other comterp's in server mode. comterp server "portnum" Listens for and accept connections on portnum, then setup a command interpreter to wait for and process commands from that connection. comterp logger "portnum" Listens for and accept connections on portnum, then simply forward the incoming messages to stdout, while ack'ing back with newlines. For debugging purposes, not really a use of the interpreter. comterp client "host" "portnum" \["file"\] Connect to a portnum on a host and send/receive new-line terminated text buffers. For debugging purposes, not really a use of the interpreter. comterp telcat "host" "portnum" \["file"\] Connect to a portnum on a host, cat the file, then close the connection. Not really a use of the interpreter either. comterp run "file" Run contents of file then exit. comterp "expr" Evaluate single expression then exit. ## OPERATOR TABLE ``` Operators Command Name Priority Order Type --------- ------------ -------- ----- ---- . dot 130 R-to-L binary ` bquote 125 R-to-L unary-prefix ! negate 110 R-to-L unary-prefix ~ bit_not 110 R-to-L unary-prefix ++ incr 110 R-to-L unary-prefix ++ incr_after 110 R-to-L unary-postfix - minus 110 R-to-L unary-prefix -- decr 110 R-to-L unary-prefix -- decr_after 110 R-to-L unary-postfix ** repeat 90 L-to-R binary .. iterate 80 L-to-R binary % mod 70 L-to-R binary * mpy 70 L-to-R binary / div 70 L-to-R binary + add 60 L-to-R binary - sub 60 L-to-R binary << lshift 55 L-to-R binary >> rshift 55 L-to-R binary < lt 50 L-to-R binary <= lt_or_eq 50 L-to-R binary > gt 50 L-to-R binary >= gt_or_eq 50 L-to-R binary != not_eq 45 L-to-R binary == eq 45 L-to-R binary & bit_and 44 L-to-R binary ^ bit_xor 43 L-to-R binary | bit_or 42 L-to-R binary && and 41 L-to-R binary || or 40 L-to-R binary , tuple 35 L-to-R binary ,, stream concat 33 L-to-R binary $ stream 32 R-to-L unary-prefix $$ list 32 R-to-L unary-prefix %= mod_assign 30 R-to-L binary *= mpy_assign 30 R-to-L binary += add_assign 30 R-to-L binary -= sub_assign 30 R-to-L binary /= div_assign 30 R-to-L binary = assign 30 R-to-L binary ; seq 10 L-to-R binary ``` ## MATHEMATICAL COMMANDS: n=min(a b) -- return minimum of a and b n=max(a b) -- return maximum of a and b n=abs(a) -- return absolute value of a dbl=exp(x) -- returns the value e raised to the power of x dbl=log(x) -- returns the natural logarithm of x dbl=log10(x) -- returns the base-10 logarithm of x dbl=log2(x) -- returns the base-2 logarithm of x dbl=pow(x y) -- returns the value of x raised to the power of y dbl=acos(x) -- returns the arc cosine of x in radians dbl=asin(x) -- returns the arc sine of x in radians dbl=atan(x) -- returns the arc tangent of x in radians dbl=atan2(y x) -- returns the arc tangent of y over x dbl=cos(x) -- returns the cosine of x radians dbl=sin(x) -- returns the sine of x radians dbl=tan(x) -- returns the tangent of x radians dbl=sqrt(x) -- returns square root of x dbl=pi() -- returns the value of pi dbl=radtodeg(dbl) -- convert radians to degrees dbl=degtorad(dbl) -- convert degrees to radians num=floor(num) -- return closest integer value less than or equal to argument num=ceil(num) -- return closest integer value greater than or equal to argument num=round(num) -- return closest integer value ## AFFINE TRANSFORM AND MATRIX COMMANDS: point=xform(x,y a00,a01,a10,a11,a20,a21) -- affine transform of x,y coordinates affine=invert(a00,a01,a10,a11,a20,a21) -- invert affine transform matrix=xpose(matrix) -- transpose an arbitrary matrix matrix=matrix\*matrix -- matrix multiplication ## STATISTICAL/RANDOM COMMANDS: sum(val1\[,val2\[,...,valn\]\]) -- return sum of values mean(val1\[,val2\[,...,valn\]\]) -- return mean of values var(val1\[,val2\[,...,valn\]\]) -- return variance of values stddev(val1\[,val2\[,...,valn\]\]) -- return standard deviation of values rand(\[minval,maxval\]) -- return random number between 0 and 1 or minval,maxval srand(seedval) -- seed random number generator ## LIST COMMANDS: lst=list(\[lst\|strm\|val\|fileobj\|pipeobj) :strmlst :attr :size n) -- create list, copy list, or convert stream val=at(lst\|attrlst\|str n :set val :ins val) -- return (or set or insert after) nth item in a list or string num=size(lst\|attrlst\|str) -- return size of a list (or string) val=index(lst\|str val\|char\|str :last :all :substr) -- return index of value (or char or string) in list (or string), nil if not found. ## STREAM COMMANDS: strm=stream(strm\|lst\|attrlst\|val\|fileobj\|pipeobj) -- copy stream or convert list (unary $) val=next(stream :skim) -- return next value from stream, don't recurse if :skim cnt=each(strm) -- traverse stream returning its length comp=filter(comps classid) -- filter stream of comps for matching classid ## CONTROL COMMANDS (using post evaluation): val=cond(testexpr trueexpr falseexpr) -- evaluate testexpr, and if true, evaluate and return trueexpr, otherwise evaluate and return falseexpr val=if(testexpr :then expr :else expr) -- evaluate testexpr and execute the :then expression if true, the :else expression if false. val=for(initexpr whileexpr \[nextexpr \[bodyexpr\]\] :body expr) -- for loop val=while(\[testexpr \[bodyexpr\]\] :nilchk :until :body expr ) -- while loop val=switch(val key-body-pairs) -- switch statement (:casen for pos., :case\_n for neg., otherwise :symbol) continue -- skip to next iteration of for or while loop break(\[retval\]) -- break out of for or while loop ## SYMBOL COMMANDS val=global(sym)\|global(sym)=val\|global(sym :clear)\|global(:cnt) -- make symbol global int\|lst=symid(\[sym \[sym ...\]\] :max :cnt) -- return integer id(s) associated with symbol(s) sym\|lst=symbol(symid \[symid ...\]) -- return symbol(s) associated with integer id(s) val\|lst=symval(symv \[symv ...\]) -- return value(s) associated with symbol variables(s) symv\|lst=symadd(sym\|str \[sym\|str ...\]) -- create symbol(s) and return without lookup. sym=symvar(symv) -- return symbol of symbol variable without lookup, for use on left hand side of assignment str=symstr(symv) -- return string version of symbol in symbol variable sym=bquote(sym) -- LISP-like backquote operator, returns symbol without lookup n=strref(str\|symid) -- return string reference count bool=eq(sym1 sym2 :sym) -- symbol comparison ## FILE COMMANDS fileobj\|pipeobj=open(\[filename \[modestr\]\] :pipe :in :out :err) -- open file command close(fileobj\|pipeobj) -- close file command \[str\]=print(\[fmtstr\] \[val \[val1 \[... valn\]\]\] :string\|:str :out :err :file fileobj\|pipeobj :prefix str) -- print value with optional format string str=gets(fileobj\|pipeobj\|sockobj) -- gets a new-line terminated string from a file ## STRING COMMANDS lst=split(sym\|str :tokstr \[delim\] :tokval \[delim\] :keep :reverse) -- split symbol or string into list of characters (or tokens). str=join(lst :sym) -- join list of characters into string str=substr(str n\|str :after :nonil) -- extract characters from a string (:nonil returns string if no match) bool=eq(str1 str2 :n len) -- partial string comparison ## ATTRIBUTE COMMANDS sym=attrname(attribute) -- return name field of dotted pair val=attrval(attribute) -- return value field of dotted pair dotlst=dot(name) -- construct empty dotted pair list ## INFO COMMANDS help(cmdname \[cmdname ...\] :all :posteval) -- help for commands optable(:bypri :byopr :bycom) -- print contents of operator table ## DEBUG COMMANDS val=trace(\[flag\] :get) -- toggle or set trace mode pause(\[msgstr\]) -- pause script execution until C/R step() -- toggle stepwise script execution mute(\[flag\]) -- set or toggle mute flag postfix(arg1 \[arg2 \[arg3 ... \[argn\]\]\]) -- echo unevaluated postfix arguments (with \[narg\|nkey\] after defined commands, {narg\|nkey} after undefined commands, (narg) after keys, and a \* following post-evaluation commands) parse(fileobj) -- parse a single expression from a file ## CONTROL COMMANDS arr=posteval(arg1 \[arg2 \[arg3 ... \[argn\]\]\]) -- post-evaluate every fixed argument (until nil) and return array quit() -- quit the interpreter exit() -- exit entire application empty() -- empty statement val=run(filename :str :popen) -- run commands from file (or string) sockobj=%s(hoststr portnum ) -- create and open socket object val=remote(hoststr\|sockobj \[portnum\] cmdstr :nowait :str) -- remotely evaluate command string then locally evaluate result string val=eval(cmdstr\|funcobj \[cmdstr\|funcobj ...\] :symret ) -- evaluate string (or funcobj) as commands, optionally return symbol instead of nil funcobj=func(body :echo) -- encapsulate a body of commands into an executable object val=shell(cmdstr) -- evaluate command in shell usleep(msec) -- sleep microseconds ## UTILITY COMMANDS nil(\[...\]) -- accept any arguments and return nil true(\[...\]) -- accept any arguments and return true false(\[...\]) -- accept any arguments and return false c=char(num :u) -- convert any numeric to a char s=short(num :u) -- convert any numeric to a short i=int(num :u) -- convert any numeric to an int l=long(num :u) -- convert any numeric to a long f=float(num) -- convert any numeric to a float d=double(num) -- convert any numeric to a double sym\|lst=type(val \[val ...\]) -- return type symbol(s) for value(s) sym\|lst=class(val \[val ...\]) -- return class symbol(s) for value(s) of object type int=ctoi(char) -- convert character to integer flag=isspace(char) -- return true if character is whitespace flag=isdigit(char) -- return true if character is a numeric digit flag=isspace(char) -- return true if character is alphabetical str=arg(n) -- return command line argument n=narg(n) -- return number of command line arguments num=nand(a b) -- bitwise NAND(negated AND) num=nor(a b) -- bitwise NOR (negated OR) num=xnor(a b) -- bitwise XNOR (negated XOR) dateobj\|int = date(\[num\|str\|dateobj\] :day :month :year :daymo :weekday) -- create date from days since 1/1/1901 or string ## ONLY IN SERVER MODE str=timeexpr(comstr :sec n) -- command string to execute at intervals ## SEE ALSO comdraw ## WEB PAGES http://www.ivtools.org/ivtools/comterp.html