#!/usr/local/bin/gawk -f
# @(#) altchars.gawk 1.2 96/11/30
# 96/05/21 john h. dubois iii
# 96/05/29 Added all options.
# 96/08/06 Added ib options.
# 96/11/30 Moved altInit code into a function
BEGIN {
    Name = "altchars"
    Usage = "Usage: " Name " [-ahobi] [-t<termtype>]"
    ARGC = Opts(Name,Usage,"abhiot:",0)
    if ("h" in Options) {
	printf \
"%s: print alternate character set for a terminal using terminfo database.\n"\
"%s\n"\
"%s prints the characters that are rendered in the alternate character set\n"\
"by terminfo-based programs that need to use the graphic (non-ASCII)\n"\
"characters that are recorded in the terminfo \"acsc\" capability.  Before\n"\
"printing the characters, these programs send a sequence that switches the\n"\
"terminal into the alternate set.  By default, %s does not send the\n"\
"character set switching sequence, so the characters it prints appear as\n"\
"they do in the acsc string.\n"\
"The 'Tag' column gives the VT100-equivalent character used in the acsc\n"\
"capability to tell what the function of each character is.\n"\
"The 'Pos' column gives the position of each character in the acsc string.\n"\
"The 'Sym' column is a symbolic representation of the character.\n"\
"acsc is used mainly to get the characters used to draw boxes.\n"\
"Options:\n"\
"-h: Print this help.\n"\
"-a: Print an extra 'Char' column with each alternate character printed with\n"\
"    the alternate character set turned on, so that they will show up as the\n"\
"    real graphic characters if the terminal interprets them correctly.\n"\
"-b: Draw a partitioned box using the alternate character set, with the\n"\
"    characters also shown as they appear in the standard character set,\n"\
"    followed the acsc tag characters.\n"\
"-i: Emit a channel map that maps some characters of the IBM graphic\n"\
"    character set into alternate character set sequences for the terminal\n"\
"    type that %s operates on.  The characters mapped are those that the\n"\
"    acsc capability defines.  If this map is installed with mapchan, an\n"\
"    application that uses those IBM graphic characters will be able to\n"\
"    display them on the terminal.  The mapchan facility does not have\n"\
"    enough room to store much output mapping, so only the box drawing\n"\
"    characters and a few others are mapped.\n"\
"-t<termtype>: Print the alternate characters for the given terminal type,\n"\
"    instead of the terminal type given by the environment variable TERM.\n"\
"-o: Print all non-printing characters in octal.  The default is to print\n"\
"    characters above ASCII value 127 in octal, and all other non-printing\n"\
"    characters in the symbolic form ^X.\n",
	Name,Usage,Name,Name,Name
	exit 0
    }
    if (ARGC > 1) {
	print Name ": invalid argument.  Use -h for help." > "/dev/stderr"
	exit 1
    }
    if ((Err = ExclusiveOptions("a,b,i,o",Options)) != "") {
	printf "Error: %s\n",Err > "/dev/stderr"
	Err = 1
	exit(1)
    }
    if ("t" in Options)
	term = Options["t"]
    else
	term = ENVIRON["TERM"]
    Octal = "o" in Options
    drawBox = "b" in Options
    AltChars = "a" in Options
    chanMap = "i" in Options
    list = !(drawBox || chanMap)
    Assign(CharNames,
    "+=arrow pointing right|,=arrow pointing left|.=arrow pointing down|"\
    "0=solid square block|I=lantern symbol|-=arrow pointing up|`=diamond|"\
    "a=checker board|f=degree symbol|g=plus/minus|h=board of squares|"\
    "j=lower right corner|k=upper right corner|l=upper left corner|"\
    "m=lower left corner|n=plus|o=scan line 1|q=horizontal line|"\
    "s=scan line 9|t=left tee|u=right tee|v=bottom tee|w=top tee|"\
    "x=vertical line|~=bullet", "|","=")
    CopySet(CharNames,vtchars)

    if (ret = altInit(tinfo,term,0,AltMap,num))
	exit ret
    caplist = "enacs,smacs,rmacs"
    split(caplist,capnames,",")
    split("Enable,Start,End",capdesc,",")
    for (i = 1; i in capnames; i++) {
	capname = capnames[i]
	if (list && capname in tinfo)
	    printf "%s alternate character set sequence: %s\n",capdesc[i],
	    Uncontrol(tinfo[capname],Octal)
    }
    acsc = tinfo["acsc"]
    # If we will be printing chars in alternate character set,
    # get start/end alt char set sequences and enable alternate character set.
    if (AltChars || drawBox || chanMap) {
	if ("smacs" in tinfo)
	    smacs = tinfo["smacs"]
	if ("rmacs" in tinfo)
	    rmacs = tinfo["rmacs"]
	if ("enacs" in tinfo)
	    printf "%s",tinfo["enacs"]
	if (AltChars)
	    printf "Char "
    }
    if (drawBox) {
	Format = "%-5s   %-5s   %s\n"
	AltMap[" "] = " "
	space = "   "
	printf Format,"Alt","Chars","Tags"
	split("lqwqk,x x x,tqnqu,x x x,mqvqj",elem,",")
	for (i = 1; i <= 5; i++) {
	    s = elem[i]
	    mapped = graphic = ""
	    for (j = 1; (c = substr(s,j,1)) != ""; j++) {
		a = AltMap[c]
		mapped = mapped a
		if (c == " ")
		    # Some terminals do not have space as space in alt charset
		    graphic = graphic rmacs " " smacs
		else
		    graphic = graphic a
	    }
	    printf Format,smacs graphic rmacs,mapped,s
	}
	exit 0
    }
    if (chanMap) {
	toMapChan(S)
	MakeMapchanTable()
	#ibmset = "0\333a\261g\361h\262j\331k\277l\332m\300n\305q\304t"\
	#"\303u\264v\301w\302x\263+\032.\031-\030`\004~\011"
	#ibmset = "j\331k\277l\332m\300n\305q\304t\303u\264v\301w\302x\263"
	ibmset = "j\331k\277l\332m\300n\305q\304t\303u\264v\301w\302x\263"\
	"~\372a\260"

	len = length(ibmset)
	for (i = 1; i < len; i += 2)
	    ibmMap[substr(ibmset,i,1)] = substr(ibmset,i+1,1)
	print "input\n\noutput\n"
	for (c in AltMap)
	    if (c in ibmMap) {
		printf "# %s\n",CharNames[c]
		printf "%s %s\n",toMapChan(ibmMap[c]),
		toMapChan(smacs AltMap[c] rmacs)
	    }
	exit 0
    }
    Format = "%-3s %3s %-5s %s\n"
    printf Format,"Tag","Pos","Sym","Description"
    for (j = 1; j in num; j++) {
	vtchar = num[j]
	altchar = AltMap[vtchar]
	if (vtchar in CharNames) {
	    if (AltChars)
		printf "%s",smacs altchar rmacs "    "
	    printf Format,vtchar,j,
	    Uncontrol(altchar,Octal),CharNames[vtchar]
	    delete vtchars[vtchar]
	}
	else
	    unknown[vtchar] = altchar
    }
    if (!(IsEmpty(unknown))) {
	print \
	"Unknown line drawing character label(s) found in acsc capability:" \
	> "/dev/stderr"
	for (char in unknown)
	    u = u char
	print Uncontrol(u,Octal) > "/dev/stderr"
    }
    if (!(IsEmpty(vtchars))) {
	print "Unassigned characters from the alternate character set:" \
	> "/dev/stderr"
	for (char in vtchars)
	    printf "%s   %s\n",char,CharNames[char] > "/dev/stderr"
    }
}

function toMapChan(S,  i,len,Output) {
    len = length(S)
    Output = ""
    for (i = 1; i <= len; i++) {
	Output = Output " " mchar2octal[substr(S,i,1)]
    }
    return substr(Output,2)
}

function MakeMapchanTable(  i,c) {
    for (i = 1; i < 32; i++)
	mchar2octal[sprintf("%c",i)] = sprintf("%3d",i)
    for (i = 32; i < 127; i++)
	mchar2octal[sprintf("%c",i)]  = sprintf("'%c'",i)
    mchar2octal[sprintf("%c",127)] = 127
    for (i = 128; i < 256; i++)
	mchar2octal[sprintf("%c",i)] = sprintf("%3d",i)
}

# altInit(): Get alternate character set terminfo capabilities.
# term, noerror: see tiget().
# tinfo: contains the acsc capability, and any of the enacs, smacs, and rmacs
# capabilities that are defined for the terminal.  Each is indexed by its
# capability name.  enacs is used to enable the alternate character set;
# smacs starts it; rmacs ends it.  acsc is the mapping of vt100 alternate
# character codes to those appropriate for the given terminal.
# AltMap is the acsc string broken down with each alternate character indexed
# by its vt100 equivalent.  num is an ordered list of the vt100 characters
# indexed starting with 1, for applications that need to know what order they
# were given in.
# The alternate characters and their indexes (vt100 equivalents) are:
# 0  solid square block		a  checker board	f  degree symbol
# g  plus/minus			h  board of squares	j  lower right corner
# k  upper right corner		l  upper left corner	m  lower left corner
# n  plus			q  horizontal line	t  left tee
# u  right tee			v  bottom tee		w  top tee
# x  vertical line		+  arrow pointing right	.  arrow pointing down
# -  arrow pointing up		,  arrow pointing left	`  diamond
# ~  bullet			I  lantern symbol	o  scan line 1
# s  scan line 9
function altInit(tinfo,term,noerror,AltMap,num,  ret,caplist,acsc,len,j,i) {
    if (ret = tiget("acsc",tinfo,term)) {
	# All other types of errors cause tput to print an informative message
	# to stderr, which is not redirected.
	if (!noerror && ret == 1)
	    printf "Terminal type %s has no acsc capability.\n",
	    term > "/dev/stderr"
	return ret
    }
    caplist = "enacs,smacs,rmacs"
    tiget(caplist,tinfo,term)
    acsc = tinfo["acsc"]
    len = length(acsc)
    j = 0
    for (i = 1; i < len; i += 2)
	AltMap[num[++j] = substr(acsc,i,1)] = substr(acsc,i+1,1)
}

# tiget: get terminfo capabilities.
# capnames is a comma-separated list of terminfo capabilities to get.
# Each capability is put in tinfo[], indexed by capability name.
# If term is passed, it is the terminal type to get the capabilities for.
# If not, the value of the environment variable TERM is used.
# If noerror is true, error messages are suppressed.
# Return value: the exit status of the last tput.
function tiget(capnames,tinfo,term,noerror,  cmd,RS,ret,names,capname,i) {
    if (term == "")
	term = ENVIRON["TERM"]
    split(capnames,names,",")
    RS = ""	# this makes the record separator be "\n\n", which hopefully
		# is not very common in terminfo capabilities
    for (i = 1; i in names; i++) {
	capname = names[i]
	cmd = "exec tput -T " term " " capname
	if (noerror)
	    cmd = cmd " 2>/dev/null"
	cmd | getline
	if (!(ret = close(cmd)))
	    # printf interprets many of the escape chars in the same manner that
	    # the terminfo library does... not perfect, but better than nothing
	    tinfo[capname] = sprintf($0)
    }
    return ret
}

### Begin array routines

# InitArr: Initialize an array with values.
# Ind and Vals are separated into lists on Sep.
# For each item in Ind, an index with that name is created in Arr[],
# and the value with the same position in Vals is stored in it.
# Global variables: none.
function InitArr(Arr,Ind,Vals,sep,  numind,indnames,values) {
    split(Ind,indnames,sep)
    split(Vals,values,sep)
    for (numind in indnames)
	Arr[indnames[numind]] = values[numind]
}

function ClearArr(Arr,  Elem) {
    for (Elem in Arr)
	delete Arr[Elem]
}
# Subtract the values in Subtrahend from those in Minuend
function SubtractArr(Minuend,Subtrahend,  Elem) {
    for (Elem in Subtrahend)
	Minuend[Elem] -= Subtrahend[Elem]
}
# For each element of the array In, an element is created in Out having
# an index equal to the value of the element in In and a value equal to 
# the index of the element in In.
function Invert(In,Out,  Index) {
    for (Index in In)
	Out[In[Index]] = Index
}

# Assign: make an array from a list of assignments.
# An index with the name of each variable in the list is created in the array.
# Its value is set to the value given for it.
# Input variables: 
# Elements is a string containing the list of variable-value pairs.
# Sep is the string that separates the pairs in the list.
# AssignOp is the string that separates variables from values.
# Output variables:
# Arr is the array.
# Return value: the number of elements added to the set.
# Example:
# Assign(Arr,"foo=blot bar=blat baz=blit"," ","=")
function Assign(Arr,Elements,Sep,AssignOp,
Num,Names,Elem,Assignments,Assignment,i) {
    Num = split(Elements,Assignments,Sep)
    for (i = 1; i <= Num; i++) {
	Assignment = Assignments[i]
	Ind = index(Assignment,AssignOp)
	Arr[substr(Assignment,1,Ind - 1)] = substr(Assignment,Ind + 1)
    }
    return Num
}

### End array routines
### Begin UnControl routines

# @(#) uncontrol.awk 1.1 96/05/29
# 92/11/09 john h. dubois iii (john@armory.com)
# 96/05/29 Added octal-only conversion.

# Uncontrol(S): Convert control characters in S to symbolic form.
# Characters in S with values < 32 and with value 127 are converted to the form
# ^X.  Characters with value >= 128 are converted to the octal form \0nnn,
# where nnn is the octal value of the character.
# The resulting string is returned.
# If OctalOnly is true, octal numbers are used for all symbolic values instead
# of ^X.
# Global variables: UncTable[] and char2octal[].
function Uncontrol(S,OctalOnly,  i,len,Output) {
    len = length(S)
    Output = ""
    if (!("a" in UncTable))
	MakeUncontrolTable()
    for (i = 1; i <= len; i++)
	Output = Output \
	(OctalOnly ? char2octal[substr(S,i,1)] : UncTable[substr(S,i,1)])
    return Output
}

# MakeUncontrolTable: Make tables for use by Uncontrol().
# Global variables:
# UncTable[] is made into a character -> symbolic character lookup table
# with characters with values < 32 and with value 127 converted to the form
# ^X, and characters with value >= 128 are converted to the octal form \0nnn.
# char2octal[] is made into a similar table but with all non-printing chars
# in the form \0nnn.
function MakeUncontrolTable(  i,c) {
    for (i = 0; i < 32; i++) {
	UncTable[c = sprintf("%c",i)] = "^" sprintf("%c",i + 64)
	char2octal[c] = "\\" sprintf("%03o",i)
    }
    for (i = 32; i < 127; i++) {
	c = sprintf("%c",i)
	char2octal[c]  = UncTable[c] = sprintf("%c",i)
    }
    UncTable[c = sprintf("%c",127)] = "^?"
    char2octal[c] = "\\0177"
    for (i = 128; i < 256; i++) {
	UncTable[c = sprintf("%c",i)] = "\\" sprintf("%03o",i)
	char2octal[c] = "\\" sprintf("%03o",i)
    }
}

### End UnControl routines
### Begin set library

function Intersection(A,B,Inter,  Elem,Count) {
    for (Elem in A)
	if (Elem in B) {
	    Inter[Elem]
	    Count++
	}
    return Count
}

function Union(A,B,Both,  Elem) {
    for (Elem in A)
	Both[Elem]
    for (Elem in B)
	Both[Elem]
}

# Deletes any elements that are in both Minuend and Subtrahend from Minuend.
function SubtractSet(Minuend,Subtrahend,  Elem) {
    for (Elem in Subtrahend)
	delete Minuend[Elem]
}

function CopySet(From,To,  Elem) {
    for (Elem in From)
	To[Elem]
}

# Returns 1 if Set is empty, 0 if not.
function IsEmpty(Set,  i) {
    for (i in Set)
	return 0
    return 1
}

# MakeSet: make a set from a list.
# An index with the name of each element of the list
# is created in the given array.
# Input variables: 
# Elements is a string containing the list of elements.
# Sep is the character that separates the elements of the list.
# Output variables:
# Set is the array.
# Return value: the number of elements added to the set.
function MakeSet(Set,Elements,Sep,  i,Num,Names) {
    Num = split(Elements,Names,Sep)
    for (i = 1; i <= Num; i++)
	Set[Names[i]]
    return Num
}
# Returns the number of elements in set Set
function NumElem(Set,  elem,Num) {
    for (elem in Set)
	Num++
    return Num
}

# Remove all elements from Set
function DeleteAll(Set,  i) {
    for (i in Set)
	delete Set[i]
}

### End set library
### Start of ProcArgs library
# @(#) ProcArgs 1.11 96/12/08
# 92/02/29 john h. dubois iii (john@armory.com)
# 93/07/18 Added "#" arg type
# 93/09/26 Do not count -h against MinArgs
# 94/01/01 Stop scanning at first non-option arg.  Added ">" option type.
#          Removed meaning of "+" or "-" by itself.
# 94/03/08 Added & option and *()< option types.
# 94/04/02 Added NoRCopt to Opts()
# 94/06/11 Mark numeric variables as such.
# 94/07/08 Opts(): Do not require any args if h option is given.
# 95/01/22 Record options given more than once.  Record option num in argv.
# 95/06/08 Added ExclusiveOptions().
# 96/01/20 Let rcfiles be a colon-separated list of filenames.
#          Expand $VARNAME at the start of its filenames.
#          Let varname=0 and -option- turn off an option.
# 96/05/05 Changed meaning of 7th arg to Opts; now can specify exactly how many
#          of the vars should be searched for in the environment.
#          Check for duplicate rcfiles.
# 96/05/13 Return more specific error values.  Note: ProcArgs() and InitOpts()
#          now return various negatives values on error, not just -1, and
#          Opts() may set Err to various positive values, not just 1.
#          Added AllowUnrecOpt.
# 96/05/23 Check type given for & option
# 96/06/15 Re-port to awk
# 96/10/01 Moved file-reading code into ReadConfFile(), so that it can be
#          used by other functions.
# 96/10/15 Added OptChars
# 96/11/01 Added exOpts arg to Opts()
# 96/11/16 Added ; type
# 96/12/08 Added Opt2Set() & Opt2Sets()
# 96/12/27 Added CmdLineOpt()

# optlist is a string which contains all of the possible command line options.
# A character followed by certain characters indicates that the option takes
# an argument, with type as follows:
# :	String argument
# ;	Non-empty string argument
# *	Floating point argument
# (	Non-negative floating point argument
# )	Positive floating point argument
# #	Integer argument
# <	Non-negative integer argument
# >	Positive integer argument
# The only difference the type of argument makes is in the runtime argument
# error checking that is done.

# The & option is a special case used to get numeric options without the
# user having to give an option character.  It is shorthand for [-+.0-9].
# If & is included in optlist and an option string that begins with one of
# these characters is seen, the value given to "&" will include the first
# char of the option.  & must be followed by a type character other than ":"
# or ";".
# Note that if e.g. &> is given, an option of -.5 will produce an error.

# Strings in argv[] which begin with "-" or "+" are taken to be
# strings of options, except that a string which consists solely of "-"
# or "+" is taken to be a non-option string; like other non-option strings,
# it stops the scanning of argv and is left in argv[].
# An argument of "--" or "++" also stops the scanning of argv[] but is removed.
# If an option takes an argument, the argument may either immediately
# follow it or be given separately.
# "-" and "+" options are treated the same.  "+" is allowed because most awks
# take any -options to be arguments to themselves.  gawk 2.15 was enhanced to
# stop scanning when it encounters an unrecognized option, though until 2.15.5
# this feature had a flaw that caused problems in some cases.  See the OptChars
# parameter to explicitly set the option-specifier characters.

# If an option that does not take an argument is given,
# an index with its name is created in Options and its value is set to the
# number of times it occurs in argv[].

# If an option that does take an argument is given, an index with its name is
# created in Options and its value is set to the value of the argument given
# for it, and Options[option-name,"count"] is (initially) set to the 1.
# If an option that takes an argument is given more than once,
# Options[option-name,"count"] is incremented, and the value is assigned to
# the index (option-name,instance) where instance is 2 for the second occurance
# of the option, etc.
# In other words, the first time an option with a value is encountered, the
# value is assigned to an index consisting only of its name; for any further
# occurances of the option, the value index has an extra (count) dimension.

# The sequence number for each option found in argv[] is stored in
# Options[option-name,"num",instance], where instance is 1 for the first
# occurance of the option, etc.  The sequence number starts at 1 and is
# incremented for each option, both those that have a value and those that
# do not.  Options set from a config file have a value of 0 assigned to this.

# Options and their arguments are deleted from argv.
# Note that this means that there may be gaps left in the indices of argv[].
# If compress is nonzero, argv[] is packed by moving its elements so that
# they have contiguous integer indices starting with 0.
# Option processing will stop with the first unrecognized option, just as
# though -- was given except that unlike -- the unrecognized option will not be
# removed from ARGV[].  Normally, an error value is returned in this case.
# If AllowUnrecOpt is true, it is not an error for an unrecognized option to
# be found, so the number of remaining arguments is returned instead.
# If OptChars is not a null string, it is the set of characters that indicate
# that an argument is an option string if the string begins with one of the
# characters.  A string consisting solely of two of the same option-indicator
# characters stops the scanning of argv[].  The default is "-+".
# argv[0] is not examined.
# The number of arguments left in argc is returned.
# If an error occurs, the global string OptErr is set to an error message
# and a negative value is returned.
# Current error values:
# -1: option that required an argument did not get it.
# -2: argument of incorrect type supplied for an option.
# -3: unrecognized (invalid) option.
function ProcArgs(argc,argv,OptList,Options,compress,AllowUnrecOpt,OptChars,
ArgNum,ArgsLeft,Arg,ArgLen,ArgInd,Option,Pos,NumOpt,Value,HadValue,specGiven,
NeedNextOpt,GotValue,OptionNum,Escape,dest,src,count,c,OptTerm,OptCharSet)
{
# ArgNum is the index of the argument being processed.
# ArgsLeft is the number of arguments left in argv.
# Arg is the argument being processed.
# ArgLen is the length of the argument being processed.
# ArgInd is the position of the character in Arg being processed.
# Option is the character in Arg being processed.
# Pos is the position in OptList of the option being processed.
# NumOpt is true if a numeric option may be given.
    ArgsLeft = argc
    NumOpt = index(OptList,"&")
    OptionNum = 0
    if (OptChars == "")
	OptChars = "-+"
    while (OptChars != "") {
	c = substr(OptChars,1,1)
	OptChars = substr(OptChars,2)
	OptCharSet[c]
	OptTerm[c c]
    }
    for (ArgNum = 1; ArgNum < argc; ArgNum++) {
	Arg = argv[ArgNum]
	if (length(Arg) < 2 || !((specGiven = substr(Arg,1,1)) in OptCharSet))
	    break	# Not an option; quit
	if (Arg in OptTerm) {
	    delete argv[ArgNum]
	    ArgsLeft--
	    break
	}
	ArgLen = length(Arg)
	for (ArgInd = 2; ArgInd <= ArgLen; ArgInd++) {
	    Option = substr(Arg,ArgInd,1)
	    if (NumOpt && Option ~ /[-+.0-9]/) {
		# If this option is a numeric option, make its flag be & and
		# its option string flag position be the position of & in
		# the option string.
		Option = "&"
		Pos = NumOpt
		# Prefix Arg with a char so that ArgInd will point to the
		# first char of the numeric option.
		Arg = "&" Arg
		ArgLen++
	    }
	    # Find position of flag in option string, to get its type (if any).
	    # Disallow & as literal flag.
	    else if (!(Pos = index(OptList,Option)) || Option == "&") {
		if (AllowUnrecOpt) {
		    Escape = 1
		    break
		}
		else {
		    OptErr = "Invalid option: " specGiven Option
		    return -3
		}
	    }

	    # Find what the value of the option will be if it takes one.
	    # NeedNextOpt is true if the option specifier is the last char of
	    # this arg, which means that if the option requires a value it is
	    # the next arg.
	    if (NeedNextOpt = (ArgInd >= ArgLen)) { # Value is the next arg
		if (GotValue = ArgNum + 1 < argc)
		    Value = argv[ArgNum+1]
	    }
	    else {	# Value is included with option
		Value = substr(Arg,ArgInd + 1)
		GotValue = 1
	    }

	    if (HadValue = AssignVal(Option,Value,Options,
	    substr(OptList,Pos + 1,1),GotValue,"",++OptionNum,!NeedNextOpt,
	    specGiven)) {
		if (HadValue < 0)	# error occured
		    return HadValue
		if (HadValue == 2)
		    ArgInd++	# Account for the single-char value we used.
		else {
		    if (NeedNextOpt) {	# option took next arg as value
			delete argv[++ArgNum]
			ArgsLeft--
		    }
		    break	# This option has been used up
		}
	    }
	}
	if (Escape)
	    break
	# Do not delete arg until after processing of it, so that if it is not
	# recognized it can be left in ARGV[].
	delete argv[ArgNum]
	ArgsLeft--
    }
    if (compress != 0) {
	dest = 1
	src = argc - ArgsLeft + 1
	for (count = ArgsLeft - 1; count; count--) {
	    ARGV[dest] = ARGV[src]
	    dest++
	    src++
	}
    }
    return ArgsLeft
}

# Assignment to values in Options[] occurs only in this function.
# Option: Option specifier character.
# Value: Value to be assigned to option, if it takes a value.
# Options[]: Options array to return values in.
# ArgType: Argument type specifier character.
# GotValue: Whether any value is available to be assigned to this option.
# Name: Name of option being processed.
# OptionNum: Number of this option (starting with 1) if set in argv[],
#     or 0 if it was given in a config file or in the environment.
# SingleOpt: true if the value (if any) that is available for this option was
#     given as part of the same command line arg as the option.  Used only for
#     options from the command line.
# specGiven is the option specifier character use, if any (e.g. - or +),
# for use in error messages.
# Global variables: OptErr
# Return value: negative value on error, 0 if option did not require an
# argument, 1 if it did & used the whole arg, 2 if it required just one char of
# the arg.
# Current error values:
# -1: Option that required an argument did not get it.
# -2: Value of incorrect type supplied for option.
# -3: Bad type given for option &
function AssignVal(Option,Value,Options,ArgType,GotValue,Name,OptionNum,
SingleOpt,specGiven,  UsedValue,Err,NumTypes) {
    # If option takes a value...    [
    NumTypes = "*()#<>]"
    if (Option == "&" && ArgType !~ "[" NumTypes) {	# ]
	OptErr = "Bad type given for & option"
	return -3
    }

    if (UsedValue = (ArgType ~ "[:;" NumTypes)) {	# ]
	if (!GotValue) {
	    if (Name != "")
		OptErr = "Variable requires a value -- " Name
	    else
		OptErr = "option requires an argument -- " Option
	    return -1
	}
	if ((Err = CheckType(ArgType,Value,Option,Name,specGiven)) != "") {
	    OptErr = Err
	    return -2
	}
	# Mark this as a numeric variable; will be propogated to Options[] val.
	if (ArgType != ":" && ArgType != ";")
	    Value += 0
	if ((Instance = ++Options[Option,"count"]) > 1)
	    Options[Option,Instance] = Value
	else
	    Options[Option] = Value
    }
    # If this is an environ or rcfile assignment & it was given a value...
    else if (!OptionNum && Value != "") {
	UsedValue = 1
	# If the value is "0" or "-" and this is the first instance of it,
	# do not set Options[Option]; this allows an assignment in an rcfile to
	# turn off an option (for the simple "Option in Options" test) in such
	# a way that it cannot be turned on in a later file.
	if (!(Option in Options) && (Value == "0" || Value == "-"))
	    Instance = 1
	else
	    Instance = ++Options[Option]
	# Save the value even though this is a flag
	Options[Option,Instance] = Value
    }
    # If this is a command line flag and has a - following it in the same arg,
    # it is being turned off.
    else if (OptionNum && SingleOpt && substr(Value,1,1) == "-") {
	UsedValue = 2
	if (Option in Options)
	    Instance = ++Options[Option]
	else
	    Instance = 1
	Options[Option,Instance]
    }
    # If this is a flag assignment without a value, increment the count for the
    # flag unless it was turned off.  The indicator for a flag being turned off
    # is that the flag index has not been set in Options[] but it has an
    # instance count.
    else if (Option in Options || !((Option,1) in Options))
	# Increment number of times this flag seen; will inc null value to 1
	Instance = ++Options[Option]
    Options[Option,"num",Instance] = OptionNum
    return UsedValue
}

# Option is the option letter
# Value is the value being assigned
# Name is the var name of the option, if any
# ArgType is one of:
# :	String argument
# ;	Non-null string argument
# *	Floating point argument
# (	Non-negative floating point argument
# )	Positive floating point argument
# #	Integer argument
# <	Non-negative integer argument
# >	Positive integer argument
# specGiven is the option specifier character use, if any (e.g. - or +),
# for use in error messages.
# Returns null on success, err string on error
function CheckType(ArgType,Value,Option,Name,specGiven,  Err,ErrStr) {
    if (ArgType == ":")
	return ""
    if (ArgType == ";") {
	if (Value == "")
	    Err = "must be a non-empty string"
    }
    # A number begins with optional + or -, and is followed by a string of
    # digits or a decimal with digits before it, after it, or both
    else if (Value !~ /^[-+]?([0-9]+|[0-9]*\.[0-9]+|[0-9]+\.)$/)
	Err = "must be a number"
    else if (ArgType ~ "[#<>]" && Value ~ /\./)
	Err = "may not include a fraction"
    else if (ArgType ~ "[()<>]" && Value < 0)
	Err = "may not be negative"
    # (
    else if (ArgType ~ "[)>]" && Value == 0)
	Err = "must be a positive number"
    if (Err != "") {
	ErrStr = "Bad value \"" Value "\".  Value assigned to "
	if (Name != "")
	    return ErrStr "variable " substr(Name,1,1) " " Err
	else {
	    if (Option == "&")
		Option = Value
	    return ErrStr "option " specGiven substr(Option,1,1) " " Err
	}
    }
    else
	return ""
}

# Note: only the above functions are needed by ProcArgs.
# The rest of these functions call ProcArgs() and also do other
# option-processing stuff.

# Opts: Process command line arguments.
# Opts processes command line arguments using ProcArgs()
# and checks for errors.  If an error occurs, a message is printed
# and the program is exited.
#
# Input variables:
# Name is the name of the program, for error messages.
# Usage is a usage message, for error messages.
# OptList the option description string, as used by ProcArgs().
# MinArgs is the minimum number of non-option arguments that this
# program should have, non including ARGV[0] and +h.
# If the program does not require any non-option arguments,
# MinArgs should be omitted or given as 0.
# rcFiles, if given, is a colon-seprated list of filenames to read for
# variable initialization.  If a filename begins with ~/, the ~ is replaced
# by the value of the environment variable HOME.  If a filename begins with
# $, the part from the character after the $ up until (but not including)
# the first character not in [a-zA-Z0-9_] will be searched for in the
# environment; if found its value will be substituted, if not the filename will
# be discarded.
# rcfiles are read in the order given.
# Values given in them will not override values given on the command line,
# and values given in later files will not override those set in earlier
# files, because AssignVal() will store each with a different instance index.
# The first instance of each variable, either on the command line or in an
# rcfile, will be stored with no instance index, and this is the value
# normally used by programs that call this function.
# VarNames is a comma-separated list of variable names to map to options,
# in the same order as the options are given in OptList.
# If EnvSearch is given and nonzero, the first EnvSearch variables will also be
# searched for in the environment.  If set to -1, all values will be searched
# for in the environment.  Values given in the environment will override
# those given in the rcfiles but not those given on the command line.
# NoRCopt, if given, is an additional letter option that if given on the
# command line prevents the rcfiles from being read.
# See ProcArgs() for a description of AllowUnRecOpt and optChars, and
# ExclusiveOptions() for a description of exOpts.
# Special options:
# If x is made an option and is given, some debugging info is output.
# h is assumed to be the help option.

# Global variables:
# The command line arguments are taken from ARGV[].
# The arguments that are option specifiers and values are removed from
# ARGV[], leaving only ARGV[0] and the non-option arguments.
# The number of elements in ARGV[] should be in ARGC.
# After processing, ARGC is set to the number of elements left in ARGV[].
# The option values are put in Options[].
# On error, Err is set to a positive integer value so it can be checked for in
# an END block.
# Return value: The number of elements left in ARGV is returned.
# Must keep OptErr global since it may be set by InitOpts().
function Opts(Name,Usage,OptList,MinArgs,rcFiles,VarNames,EnvSearch,NoRCopt,
AllowUnrecOpt,optChars,exOpts,  ArgsLeft,e) {
    if (MinArgs == "")
	MinArgs = 0
    ArgsLeft = ProcArgs(ARGC,ARGV,OptList NoRCopt,Options,1,AllowUnrecOpt,
    optChars)
    if (ArgsLeft < (MinArgs+1) && !("h" in Options)) {
	if (ArgsLeft >= 0) {
	    OptErr = "Not enough arguments"
	    Err = 4
	}
	else
	    Err = -ArgsLeft
	printf "%s: %s.\nUse -h for help.\n%s\n",
	Name,OptErr,Usage > "/dev/stderr"
	exit 1
    }
    if (rcFiles != "" && (NoRCopt == "" || !(NoRCopt in Options)) &&
    (e = InitOpts(rcFiles,Options,OptList,VarNames,EnvSearch)) < 0)
    {
	print Name ": " OptErr ".\nUse -h for help." > "/dev/stderr"
	Err = -e
	exit 1
    }
    if ((exOpts != "") && ((OptErr = ExclusiveOptions(exOpts,Options)) != ""))
    {
	printf "%s: Error: %s\n",Name,OptErr > "/dev/stderr"
	Err = 1
	exit 1
    }
    return ArgsLeft
}

# ReadConfFile(): Read a file containing var/value assignments, in the form
# <variable-name><assignment-char><value>.
# Whitespace (spaces and tabs) around a variable (leading whitespace on the
# line and whitespace between the variable name and the assignment character) 
# is stripped.  Lines that do not contain an assignment operator or which
# contain a null variable name are ignored, other than possibly being noted in
# the return value.  If more than one assignment is made to a variable, the
# first assignment is used.
# Input variables:
# File is the file to read.
# Comment is the line-comment character.  If it is found as the first non-
#     whitespace character on a line, the line is ignored.
# Assign is the assignment string.  The first instance of Assign on a line
#     separates the variable name from its value.
# If StripWhite is true, whitespace around the value (whitespace between the
#     assignment char and trailing whitespace on the line) is stripped.
# VarPat is a pattern that variable names must match.  
#     Example: "^[a-zA-Z][a-zA-Z0-9]+$"
# If FlagsOK is true, variables are allowed to be "set" by being put alone on
#     a line; no assignment operator is needed.  These variables are set in
#     the output array with a null value.  Lines containing nothing but
#     whitespace are still ignored.
# Output variables:
# Values[] contains the assignments, with the indexes being the variable names
#     and the values being the assigned values.
# Lines[] contains the line number that each variable occured on.  A flag set
#     is record by giving it an index in Lines[] but not in Values[].
# Return value:
# If any errors occur, a string consisting of descriptions of the errors
# separated by newlines is returned.  In no case will the string start with a
# numeric value.  If no errors occur,  the number of lines read is returned.
function ReadConfigFile(Values,Lines,File,Comment,Assign,StripWhite,VarPat,
FlagsOK,
Line,Status,Errs,AssignLen,LineNum,Var,Val) {
    if (Comment != "")
	Comment = "^" Comment
    AssignLen = length(Assign)
    if (VarPat == "")
	VarPat = "."	# null varname not allowed
    while ((Status = (getline Line < File)) == 1) {
	LineNum++
	sub("^[ \t]+","",Line)
	if (Line == "")		# blank line
	    continue
	if (Comment != "" && Line ~ Comment)
	    continue
	if (Pos = index(Line,Assign)) {
	    Var = substr(Line,1,Pos-1)
	    Val = substr(Line,Pos+AssignLen)
	    if (StripWhite) {
		sub("^[ \t]+","",Val)
		sub("[ \t]+$","",Val)
	    }
	}
	else {
	    Var = Line	# If no value, var is entire line
	    Val = ""
	}
	if (!FlagsOK && Val == "") {
	    Errs = Errs \
	    sprintf("\nBad assignment on line %d of file %s: %s",
	    LineNum,File,Line)
	    continue
	}
	sub("[ \t]+$","",Var)
	if (Var !~ VarPat) {
	    Errs = Errs sprintf("\nBad variable name on line %d of file %s: %s",
	    LineNum,File,Var)
	    continue
	}
	if (!(Var in Lines)) {
	    Lines[Var] = LineNum
	    if (Pos)
		Values[Var] = Val
	}
    }
    if (Status)
	Errs = Errs "\nCould not read file " File
    close(File)
    return Errs == "" ? LineNum : substr(Errs,2)	# Skip first newline
}

# Variables:
# Data is stored in Options[].
# rcFiles, OptList, VarNames, and EnvSearch are as as described for Opts().
# Global vars:
# Sets OptErr.  Uses ENVIRON[].
# If anything is read from any of the rcfiles, sets READ_RCFILE to 1.
function InitOpts(rcFiles,Options,OptList,VarNames,EnvSearch,
Line,Var,Pos,Vars,Map,CharOpt,NumVars,TypesInd,Types,Type,Ret,i,rcFile,
fNames,numrcFiles,filesRead,Err,Values,retStr) {
    split("",filesRead,"")	# make awk know this is an array
    NumVars = split(VarNames,Vars,",")
    TypesInd = Ret = 0
    if (EnvSearch == -1)
	EnvSearch = NumVars
    for (i = 1; i <= NumVars; i++) {
	Var = Vars[i]
	CharOpt = substr(OptList,++TypesInd,1)
	if (CharOpt ~ "^[:;*()#<>&]$")
	    CharOpt = substr(OptList,++TypesInd,1)
	Map[Var] = CharOpt
	Types[Var] = Type = substr(OptList,TypesInd+1,1)
	# Do not overwrite entries from environment
	if (i <= EnvSearch && Var in ENVIRON &&
	(Err = AssignVal(CharOpt,ENVIRON[Var],Options,Type,1,Var,0)) < 0)
	    return Err
    }

    numrcFiles = split(rcFiles,fNames,":")
    for (i = 1; i <= numrcFiles; i++) {
	rcFile = fNames[i]
	if (rcFile ~ "^~/")
	    rcFile = ENVIRON["HOME"] substr(rcFile,2)
	else if (rcFile ~ /^\$/) {
	    rcFile = substr(rcFile,2)
	    match(rcFile,"^[a-zA-Z0-9_]*")
	    envvar = substr(rcFile,1,RLENGTH)
	    if (envvar in ENVIRON)
		rcFile = ENVIRON[envvar] substr(rcFile,RLENGTH+1)
	    else
		continue
	}
	if (rcFile in filesRead)
	    continue
	# rcfiles are liable to be given more than once, e.g. UHOME and HOME
	# may be the same
	filesRead[rcFile]
	if ("x" in Options)
	    printf "Reading configuration file %s\n",rcFile > "/dev/stderr"
	retStr = ReadConfigFile(Values,Lines,rcFile,"#","=",0,"",1)
	if (retStr > 0)
	    READ_RCFILE = 1
	else if (ret != "") {
	    OptErr = retStr
	    Ret = -1
	}
	for (Var in Lines)
	    if (Var in Map) {
		if ((Err = AssignVal(Map[Var],
		Var in Values ? Values[Var] : "",Options,Types[Var],
		Var in Values,Var,0)) < 0)
		    return Err
	    }
	    else {
		OptErr = sprintf(\
		"Unknown var \"%s\" assigned to on line %d\nof file %s",Var,
		Lines[Var],rcFile)
		Ret = -1
	    }
    }

    if ("x" in Options)
	for (Var in Map)
	    if (Map[Var] in Options)
		printf "(%s) %s=%s\n",Map[Var],Var,Options[Map[Var]] > \
		"/dev/stderr"
	    else
		printf "(%s) %s not set\n",Map[Var],Var > "/dev/stderr"
    return Ret
}

# OptSets is a semicolon-separated list of sets of option sets.
# Within a list of option sets, the option sets are separated by commas.  For
# each set of sets, if any option in one of the sets is in Options[] AND any
# option in one of the other sets is in Options[], an error string is returned.
# If no conflicts are found, nothing is returned.
# Example: if OptSets = "ab,def,g;i,j", an error will be returned due to
# the exclusions presented by the first set of sets (ab,def,g) if:
# (a or b is in Options[]) AND (d, e, or f is in Options[]) OR
# (a or b is in Options[]) AND (g is in Options) OR
# (d, e, or f is in Options[]) AND (g is in Options)
# An error will be returned due to the exclusions presented by the second set
# of sets (i,j) if: (i is in Options[]) AND (j is in Options[]).
# todo: make options given on command line unset options given in config file
# todo: that they conflict with.
function ExclusiveOptions(OptSets,Options,
Sets,SetSet,NumSets,Pos1,Pos2,Len,s1,s2,c1,c2,ErrStr,L1,L2,SetSets,NumSetSets,
SetNum,OSetNum) {
    NumSetSets = split(OptSets,SetSets,";")
    # For each set of sets...
    for (SetSet = 1; SetSet <= NumSetSets; SetSet++) {
	# NumSets is the number of sets in this set of sets.
	NumSets = split(SetSets[SetSet],Sets,",")
	# For each set in a set of sets except the last...
	for (SetNum = 1; SetNum < NumSets; SetNum++) {
	    s1 = Sets[SetNum]
	    L1 = length(s1)
	    for (Pos1 = 1; Pos1 <= L1; Pos1++)
		# If any of the options in this set was given, check whether
		# any of the options in the other sets was given.  Only check
		# later sets since earlier sets will have already been checked
		# against this set.
		if ((c1 = substr(s1,Pos1,1)) in Options)
		    for (OSetNum = SetNum+1; OSetNum <= NumSets; OSetNum++) {
			s2 = Sets[OSetNum]
			L2 = length(s2)
			for (Pos2 = 1; Pos2 <= L2; Pos2++)
			    if ((c2 = substr(s2,Pos2,1)) in Options)
				ErrStr = ErrStr "\n"\
				sprintf("Cannot give both %s and %s options.",
				c1,c2)
		    }
	}
    }
    if (ErrStr != "")
	return substr(ErrStr,2)
    return ""
}

# The value of each instance of option Opt that occurs in Options[] is made an
# index of Set[].
# The return value is the number of instances of Opt in Options.
function Opt2Set(Options,Opt,Set,  count) {
    if (!(Opt in Options))
	return 0
    Set[Options[Opt]]
    count = Options[Opt,"count"]
    for (; count > 1; count--)
	Set[Options[Opt,count]]
    return count
}

# The value of each instance of option Opt that occurs in Options[] that
# begins with "!" is made an index of nSet[] (with the ! stripped from it).
# Other values are made indexes of Set[].
# The return value is the number of instances of Opt in Options.
function Opt2Sets(Options,Opt,Set,nSet,  count,aSet,ret) {
    ret = Opt2Set(Options,Opt,aSet)
    for (value in aSet)
	if (substr(value,1,1) == "!")
	    nSet[substr(value,2)]
	else
	    Set[value]
    return ret
}

# Returns true if option Opt was given on the command line.
function CmdLineOpt(Options,Opt,  i) {
    for (i = 1; (Opt,"num",i) in Options; i++)
	if (Options[Opt,"num",i] != 0)
	    return 1
    return 0
}
### End of ProcArgs library