Newsgroups: comp.sources.unix
From: koblas@mips.com (David Koblas)
Subject: v26i080: op - a tool to allow customizable super user access, Part01/01
Sender: unix-sources-moderator@pa.dec.com
Approved: vixie@pa.dec.com

Submitted-By: koblas@mips.com (David Koblas)
Posting-Number: Volume 26, Issue 80
Archive-Name: op/part01

'op' is a tool designed to allow customizable super user access,
you can do everthing from emulating giving a super user shell
for nothing to only allowing one or two users access via login
names, or special passwords that are neither root, nor their own.

Plus, as an added bonus, for those commands that you would like
users to be able to use, but need to place restrictions on the
arguments, you can configure that as well.  (ie. if you want
your users to be able to mount NFS file systems).

Op was orginally developed at Convex by Tom Christiansen, and
subsequently publised in a USENEX LISA procedings.  This version
was developed entierly from the description that was published.

This release is the first official release of 'op', for those of you
who have the alpha release, only two tiny fixes have been made.  
It has been sudgested that I get the syslog logging to conform to
the Convex version, but this will follow in a latter patch.

If you have any problems or find any bugs, please report them to:

			op-bugs@mips.com

Enjoy,

David Koblas			(koblas@mips.com)

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of archive 1 (of 1)."
# Contents:  MANIFEST Makefile README atov.c defs.h lex.l main.c op.1
#   op.access regerror.c regexp.c regexp.h regmagic.h regsub.c
#   vfprintf.c
# Wrapped by vixie@cognition.pa.dec.com on Sun Dec 27 15:09:10 1992
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'MANIFEST' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'MANIFEST'\"
else
echo shar: Extracting \"'MANIFEST'\" \(579 characters\)
sed "s/^X//" >'MANIFEST' <<'END_OF_FILE'
X   File Name		Archive #	Description
X-----------------------------------------------------------
X MANIFEST                   1	This shipping list
X Makefile                   1	
X README                     1	
X atov.c                     1	
X defs.h                     1	
X lex.l                      1	
X main.c                     1	
X op.1                       1	
X op.access                  1	
X regerror.c                 1	
X regexp.c                   1	
X regexp.h                   1	
X regmagic.h                 1	
X regsub.c                   1	
X vfprintf.c                 1	
END_OF_FILE
if test 579 -ne `wc -c <'MANIFEST'`; then
    echo shar: \"'MANIFEST'\" unpacked with wrong size!
fi
# end of 'MANIFEST'
fi
if test -f 'Makefile' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'Makefile'\"
else
echo shar: Extracting \"'Makefile'\" \(346 characters\)
sed "s/^X//" >'Makefile' <<'END_OF_FILE'
CFLAGS=-g -I.
X
VPF = vfprintf.o
REG = regexp.o regsub.o regerror.o
OBJ = lex.o main.o atov.o $(REG) $(VPF)
X
all: op
X
op: $(OBJ) $(REG)
X	$(CC) $(CFLAGS) -o $@ $(OBJ) -ll
X
clean:
X	rm -f $(OBJ) op core 
X
kit:
X	@makekit README \
X		atov.c defs.h lex.l main.c op.1 \
X		op.access regerror.c regexp.c regexp.h regmagic.h \
X		regsub.c vfprintf.c Makefile
END_OF_FILE
if test 346 -ne `wc -c <'Makefile'`; then
    echo shar: \"'Makefile'\" unpacked with wrong size!
fi
# end of 'Makefile'
fi
if test -f 'README' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'README'\"
else
echo shar: Extracting \"'README'\" \(1079 characters\)
sed "s/^X//" >'README' <<'END_OF_FILE'
X'op' is a tool designed to allow customizable super user access,
you can do everthing from emulating giving a super user shell
for nothing to only allowing one or two users access via login
names, or special passwords that are neither root, nor their own.
X
Plus, as an added bonus, for those commands that you would like
users to be able to use, but need to place restrictions on the
arguments, you can configure that as well.  (ie. if you want
your users to be able to mount NFS file systems).
X
Op was orginally developed at Convex by Tom Christiansen, and
subsequently publised in a USENEX LISA procedings.  This version
was developed entierly from the description that was published.
X
This release is the first official release of 'op', for those of you
who have the alpha release, only two tiny fixes have been made.  
It has been sudgested that I get the syslog logging to conform to
the Convex version, but this will follow in a latter patch.
X
If you have any problems or find any bugs, please report them to:
X
X			op-bugs@mips.com
X
XEnjoy,
X
David Koblas			(koblas@mips.com)
END_OF_FILE
if test 1079 -ne `wc -c <'README'`; then
    echo shar: \"'README'\" unpacked with wrong size!
fi
# end of 'README'
fi
if test -f 'atov.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'atov.c'\"
else
echo shar: Extracting \"'atov.c'\" \(1561 characters\)
sed "s/^X//" >'atov.c' <<'END_OF_FILE'
X/* +-------------------------------------------------------------------+ */
X/* | Copyright 1988,1991, David Koblas.                                | */
X/* |   Permission to use, copy, modify, and distribute this software   | */
X/* |   and its documentation for any purpose and without fee is hereby | */
X/* |   granted, provided that the above copyright notice appear in all | */
X/* |   copies and that both that copyright notice and this permission  | */
X/* |   notice appear in supporting documentation.  This software is    | */
X/* |   provided "as is" without express or implied warranty.           | */
X/* +-------------------------------------------------------------------+ */
X
X#include	<ctype.h>
X
X#ifdef TEST
main(argc,argv)
int	argc;
char	**argv;
X{
X	int	i;
X	for (i=1;i<argc;i++)
X		printf("%10s  == %d\n",argv[i],atov(argv[i],0));
X}
X#endif
X
atov(str,type)
char	*str;
int	type;
X{
X	int		sign = 1;
X	int		i;
X	char		c;
X	int		val=0,n;
X
X	i=0;
X	while ((str[i]==' ') || (str[i]=='\t')) i++;
X	if (str[i]=='-')  {
X		sign = -1;
X		i++;
X	} else if (str[i]=='+') {
X		sign = 1;
X		i++;
X	}
X	if (type==0)  {
X		if (str[i]=='0') {
X			i++;
X			if (str[i]=='%') {
X				i++;
X				type=2;
X			} else if (str[i]=='x') {
X				i++;
X				type=16;
X			} else {
X				type=8;
X			}
X		} else {
X			type=10;
X		}
X	}
X	for (;i<strlen(str);i++) {
X		c=str[i];
X		if (isdigit(c)) {
X			n = c - '0';
X		} else if (isupper(c)) {
X			n = c - 'A' + 10;
X		} else if (islower(c)) {
X			n = c - 'a' + 10;
X		} else {
X			goto	out;
X		}
X		if (n>=type)
X			goto out;
X		val = (val*type)+n;
X	}
out:	
X	return(val * sign);
X}
END_OF_FILE
if test 1561 -ne `wc -c <'atov.c'`; then
    echo shar: \"'atov.c'\" unpacked with wrong size!
fi
# end of 'atov.c'
fi
if test -f 'defs.h' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'defs.h'\"
else
echo shar: Extracting \"'defs.h'\" \(870 characters\)
sed "s/^X//" >'defs.h' <<'END_OF_FILE'
X/* +-------------------------------------------------------------------+ */
X/* | Copyright 1991, David Koblas.                                     | */
X/* |   Permission to use, copy, modify, and distribute this software   | */
X/* |   and its documentation for any purpose and without fee is hereby | */
X/* |   granted, provided that the above copyright notice appear in all | */
X/* |   copies and that both that copyright notice and this permission  | */
X/* |   notice appear in supporting documentation.  This software is    | */
X/* |   provided "as is" without express or implied warranty.           | */
X/* +-------------------------------------------------------------------+ */
X
typedef struct cmd_s {
X	char		*name;
X	int		nargs, nopts;
X	int		margs, mopts;
X	char		**args, **opts;
X	struct cmd_s	*next;
X} cmd_t;
X
extern cmd_t	*First, *Build();
X
X#define MAXSTRLEN	256
END_OF_FILE
if test 870 -ne `wc -c <'defs.h'`; then
    echo shar: \"'defs.h'\" unpacked with wrong size!
fi
# end of 'defs.h'
fi
if test -f 'lex.l' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'lex.l'\"
else
echo shar: Extracting \"'lex.l'\" \(5725 characters\)
sed "s/^X//" >'lex.l' <<'END_OF_FILE'
X%{
X/* +-------------------------------------------------------------------+ */
X/* | Copyright 1991, David Koblas.                                     | */
X/* |   Permission to use, copy, modify, and distribute this software   | */
X/* |   and its documentation for any purpose and without fee is hereby | */
X/* |   granted, provided that the above copyright notice appear in all | */
X/* |   copies and that both that copyright notice and this permission  | */
X/* |   notice appear in supporting documentation.  This software is    | */
X/* |   provided "as is" without express or implied warranty.           | */
X/* +-------------------------------------------------------------------+ */
X
X#include <stdio.h>
X#include <varargs.h>
X#include <ctype.h>
X#include "defs.h"
X
static cmd_t	*newcmd();
char	*savestr();
X
extern char	*index();
X
int	yyline = 1;
X
X%}
X
WS		[ \t]*
NWS		[^ \n\t;]+
X
X%s ARGS
X
X%%
X	int	state = 0;
X	cmd_t	*cmd;
X
X#[^\n]*			;
X\n			{ yyline++; BEGIN 0; }
X^[^ \n\t]+		{ cmd = newcmd(yytext); 
X				state = (strcmp(yytext,"DEFAULT")==0) ? 1 : 0;
X				BEGIN ARGS; }
X^{WS}			BEGIN ARGS;
X<ARGS>";"		state++;
X<ARGS>{NWS}		addarg(state, cmd, yytext);
X<ARGS>{WS}		;
X%%
X#include <sys/types.h>
X#include <sys/stat.h>
X#include <syslog.h>
X
msg(va_alist)
X va_dcl
X{
X#if 0
X	va_list	ap;
X	char	*s;
X
X	va_start(ap);
X	s = va_arg(ap, char *);
X	fprintf(stderr,"line %d: ",yyline);
X	vfprintf(stderr, s, ap);
X	fputc('\n', stderr);
X	va_end(ap);
X#endif
X}
X
static addarg(state, cmd, str)
int	state;
cmd_t	*cmd;
char	*str;
X{
X	if (state == 0) {
X		msg("cmd='%s' add arg '%s'",cmd->name,str);
X		if (cmd->margs == cmd->nargs)  {
X			cmd->margs += cmd->margs;
X			cmd->args = (char **)realloc(cmd->args, 
X					sizeof(char *) * cmd->margs);
X			if (cmd->args == NULL)
X				fatal("Unable to groupw args");
X		}
X		cmd->args[cmd->nargs++] = savestr(str);
X	} else if (state == 1) {
X		msg("cmd='%s' add opt '%s'",cmd->name,str);
X		if (cmd->mopts == cmd->nopts) {
X			cmd->mopts += cmd->mopts;
X			cmd->opts = (char **)realloc(cmd->opts, 
X					sizeof(char *) * cmd->mopts);
X			if (cmd->opts == NULL)
X				fatal("Unable to groupw opts");
X		}
X		cmd->opts[cmd->nopts++] = savestr(str);
X	} else {
X		fatal("bad state (%d) received\n",state);
X	}
X}
X
char	*savestr(str)
char	*str;
X{
X	char	*s = (char *)malloc(strlen(str)+1);
X
X	if (s == NULL) 
X		fatal("No string space");
X
X	strcpy(s, str);
X	return s;
X}
X
static cmd_t	*newcmd(name)
char	*name;
X{
X	cmd_t	*cmd = (cmd_t *)malloc(sizeof(cmd_t));
X
X	cmd->next = First;
X	First = cmd;
X
X	if (cmd == NULL)
X		fatal("Unable to alloc space for new command");
X
X	cmd->name = savestr(name);
X	cmd->nargs = 0;		cmd->margs = 16;
X	cmd->nopts = 0;		cmd->mopts = 16;
X	cmd->args = (char **)malloc(sizeof(char *)*cmd->margs);
X	cmd->opts = (char **)malloc(sizeof(char *)*cmd->mopts);
X
X	return cmd;
X}
X
ReadFile(file)
char	*file;
X{
X	struct stat	statbuf;
X	FILE		*fd;
X	
X	if ((stat(file, &statbuf) < 0) || 
X		(statbuf.st_uid != 0) || /* Owned by root */
X		((statbuf.st_mode & 0077) != 0)) {/* no perm */
X		syslog(LOG_ERR, "Permission problems on %s", file);
X		fatal("Permission problems on %s", file);
X	}
X	if ((fd = fopen(file,"r")) == NULL) {
X		syslog(LOG_ERR, "Couldn't open on %s", file);
X		fatal("Couldn't open %s", file);
X	}
X
X	yyin = fd;
X	yylex();
X
X	return 0;
X}
X
CountArgs(cmd)
cmd_t	*cmd;
X{
X	int	i, val;
X	int	wild = 0, max = 0;
X	char	*cp, *np, str[MAXSTRLEN];
X
X	for (i = 0; i < cmd->nargs; i++) {
X		np = cmd->args[i];
X
X		while ((cp = index(np, '$')) != NULL) {
X			if ((cp != cmd->args[i]) && (*(cp-1) == '\\'))
X				np = cp + 1;
X			else
X				break;
X		}
X
X		if (cp == NULL)
X			continue;
X		if (*(cp+1) == '*') {
X			wild = 1;
X			continue;
X		}
X		
X		cp++;
X		np = cp;
X		
X		while (isdigit(*cp))
X			cp++;
X		if ((cp - np) == 0)
X			continue;
X		strncpy(str, np, cp - np);
X		str[cp - np] = '\0';
X		val = atoi(str);
X		if (val > max)
X			max = val;
X	}
X
X	if (wild)
X		return -max;
X	return max;
X}
X
static int	cmpopts(a, b)
char	*a, *b;
X{
X	char	*cp_a, *cp_b;
X	int	val_a, val_b;
X	char	str_a[MAXSTRLEN], str_b[MAXSTRLEN];
X
X	if (*a != '$' && *b != '$')
X		return 0;
X	if (*a == '$' && *b != '$')
X		return -1;
X	if (*a != '$' && *b == '$')
X		return  1;
X
X	cp_a = ++a;
X	cp_b = ++b;
X	while ((*cp_a != '\0') && (*cp_a != '='))
X		if (! isdigit(*cp_a))
X			break;
X	while ((*cp_b != '\0') && (*cp_b != '='))
X		if (! isdigit(*cp_b))
X			break;
X	
X	if (*cp_a != '=' && *cp_b != '=')
X		return 0;
X	if (*cp_a == '=' && *cp_b != '=')
X		return -1;
X	if (*cp_a != '=' && *cp_b == '=')
X		return  1;
X
X	strncpy(str_a, a, cp_a - a);
X	str_a[cp_a - a] = '\0';
X	val_a = atoi(str_a);
X	strncpy(str_b, b, cp_b - a);
X	str_a[cp_b - b] = '\0';
X	val_b = atoi(str_b);
X
X	if (val_a < val_b)
X		return -1;
X	if (val_a > val_b)
X		return  1;
X	return 0;
X}
X
sortopts(cmd)
cmd_t	*cmd;
X{
X	qsort(cmd->opts, cmd->nopts, sizeof(char *), cmpopts);
X}
X
cmd_t	*Build(def, cmd)
cmd_t	*def, *cmd;
X{
X	cmd_t		*new = newcmd("");
X	char		defname[MAXSTRLEN], optname[MAXSTRLEN], *cp;
X	int		i, j;
X	extern char	*index();
X
X	if (cmd == NULL)
X		return def;
X	if (def == NULL)
X		return cmd;
X
X	for (i = 0; i < cmd->nargs; i++)
X		addarg(0, new, cmd->args[i]);
X
X	for (i = 0; i < def->nopts; i++) {
X		if ((cp = index(def->opts[i], '=')) == NULL)
X			strcpy(defname, def->opts[i]);
X		else {
X			int	l = cp - def->opts[i];
X			strncpy(defname, def->opts[i], l);
X			defname[l] = '\0';
X		}
X		for (j = 0; j < cmd->nopts; j++) {
X			if ((cp = index(cmd->opts[j], '=')) == NULL)
X				strcpy(optname, cmd->opts[j]);
X			else {
X				int	l = cp - cmd->opts[j];
X				strncpy(optname, cmd->opts[j], l);
X				optname[l] = '\0';
X			}
X			if (strcmp(defname, optname) == 0)
X				def->opts[i][0] = '\0';
X		}
X		if (def->opts[i][0] != '\0')
X			addarg(1, new, def->opts[i]);
X	}
X	for (j = 0; j < cmd->nopts; j++)
X		addarg(1, new, cmd->opts[j]);
X
X	/* sortopts(new); */
X
X	return new;
X}
END_OF_FILE
if test 5725 -ne `wc -c <'lex.l'`; then
    echo shar: \"'lex.l'\" unpacked with wrong size!
fi
# end of 'lex.l'
fi
if test -f 'main.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'main.c'\"
else
echo shar: Extracting \"'main.c'\" \(11440 characters\)
sed "s/^X//" >'main.c' <<'END_OF_FILE'
X/* +-------------------------------------------------------------------+ */
X/* | Copyright 1991, David Koblas.                                     | */
X/* |   Permission to use, copy, modify, and distribute this software   | */
X/* |   and its documentation for any purpose and without fee is hereby | */
X/* |   granted, provided that the above copyright notice appear in all | */
X/* |   copies and that both that copyright notice and this permission  | */
X/* |   notice appear in supporting documentation.  This software is    | */
X/* |   provided "as is" without express or implied warranty.           | */
X/* +-------------------------------------------------------------------+ */
X
X#include <stdio.h>
X#include <varargs.h>
X#include <syslog.h>
X#include <pwd.h>
X#include <grp.h>
X#include <ctype.h>
X#include "defs.h"
X#include "regexp.h"
X
X#ifndef LOG_AUTH
X/*
X**  Pmax's don't have LOG_AUTH
X*/
X#define LOG_AUTH LOG_WARNING
X#endif
X
X/*
X**  File containing 'op' definitions.
X*/
X#define ACCESS_FILE	"/etc/op.access"
X
X#define	MAXARG	1024
X#define	MAXENV	MAXARG
X
extern char	*index();
extern char	*savestr();
extern char	*getpass(), *crypt();
X
char	*Progname;
cmd_t	*Find();
cmd_t	*First = NULL;
X
Usage()
X{
X	fatal("Usage: %s mnemonic [args]\n       %s -h [-u username] mnemonic",
X			Progname, Progname);
X}
X
main(argc, argv)
int	argc;
char	**argv;
X{
X	int		num, argStart = 1;
X	char		user[MAXSTRLEN];
X	cmd_t		*cmd, *def, *new;
X	struct passwd	*pw;
X	int		hflag = 0;
X	char		*uptr = NULL;
X
X	Progname = argv[0];
X
X	while (1) {
X		if (argStart >= argc)
X			break;
X
X		if (strcmp("-h", argv[argStart]) == 0) {
X			hflag++;
X			argStart++;
X		} else if (strcmp("-u", argv[argStart]) == 0) {
X			if (strlen(argv[argStart]) == 2) {
X				if (argStart+1 >= argc)
X					Usage();
X				argStart++;
X				uptr = argv[argStart];
X			}
X			argStart++;
X		} else if (strcmp("-uh", argv[argStart]) == 0) {
X			hflag++;
X			if (strlen(argv[argStart]) == 3) {
X				if (argStart+1 >= argc)
X					Usage();
X				argStart++;
X				uptr = argv[argStart];
X			}
X			argStart++;
X		} else if (strcmp("-hu", argv[argStart]) == 0) {
X			hflag++;
X			if (strlen(argv[argStart]) == 3) {
X				if (argStart+1 >= argc)
X					Usage();
X				argStart++;
X				uptr = argv[argStart];
X			}
X			argStart++;
X		} else {
X			break;
X		}
X	}
X
X	if (openlog("op", 0, LOG_AUTH) < 0) 
X		fatal("openlog failed");
X
X	ReadFile(ACCESS_FILE);
X
X	if (hflag) {
X		if (uptr != NULL) {
X			if (getuid() != 0) 
X				fatal("Permission denied for -u option");
X		}
X	}
X	if (uptr != NULL) 
X		Usage();
X
X	if (argStart >= argc)
X		Usage();
X
X	def = Find("DEFAULT");
X	cmd = Find(argv[argStart]);
X
X	if (cmd == NULL) 
X		fatal("No such command %s", argv[1]);
X
X	argc -= argStart;
X	argv += argStart;
X
X	new = Build(def, cmd);
X	num = CountArgs(new);
X
X	if ((num < 0) && ((argc-1) < -num))
X		fatal("Improper number of arguments");
X	if ((num > 0) && ((argc-1) != num)) 
X		fatal("Improper number of arguments");
X	if (num <0)
X		num = -num;
X
X	if ((pw = getpwuid(getuid())) == NULL) 
X		exit(1);
X	strcpy(user, pw->pw_name);
X	if (Verify(new, num, argc, argv) < 0) {
X		syslog(LOG_NOTICE, "user %s FAILED to execute '%s'", 
X				user, argv[0]);
X		fatal("Permission denied");
X	} else {
X		syslog(LOG_NOTICE, "user %s SUCCEDED to execute '%s'",
X				user, argv[0]);
X	}
X
X	return Go(new, num, argc, argv);
X}
X
fatal(va_alist)
X va_dcl
X{
X	va_list	ap;
X	char	*s;
X
X	va_start(ap);
X	s = va_arg(ap, char *);
X	vfprintf(stderr, s, ap);
X	fputc('\n', stderr);
X	va_end(ap);
X
X	exit(1);
X}
X
cmd_t	*Find(name)
char	*name;
X{
X	cmd_t	*cmd;
X
X	for (cmd = First; cmd != NULL; cmd = cmd ->next) {
X		if (strcmp(cmd->name, name) == 0)
X			break;
X	}
X
X	return cmd;
X}
X
char	*FindOpt(cmd, str)
cmd_t	*cmd;
char	*str;
X{
X	static char	nul[2] = "";
X	int		i;
X	char		*cp;
X
X	for (i = 0; i < cmd->nopts; i++) {
X		if ((cp = index(cmd->opts[i], '=')) == NULL) {
X			if (strcmp(cmd->opts[i], str) == 0)
X				return nul;
X		} else {
X			int	l = cp - cmd->opts[i];
X			if (strncmp(cmd->opts[i], str, l) == 0)
X				return cp+1;
X		}
X	}
X
X	return NULL;
X}
X
char	*GetField(cp, str)
char	*cp, *str;
X{
X	if (*cp == '\0')
X		return NULL;
X
X	while ((*cp != '\0') && (*cp != ',')) {
X		if (*cp == '\\')
X			if (*(cp+1) == ',') {
X				*str++ = ',';
X				cp++;
X			} else
X				*str++ = '\\';
X		else
X			*str++ = *cp;
X		cp++;
X	}
X
X	*str = '\0';
X
X	return (*cp == '\0') ? cp : (cp+1);
X}
X
Verify(cmd, num, argc, argv)
cmd_t	*cmd;
int	argc;
int	num;
char	**argv;
X{
X	int		gr_fail = 1, uid_fail = 1;
X	int		i, j, val;
X	char		*np, *cp, str[MAXSTRLEN], buf[MAXSTRLEN];
X	regexp		*reg = NULL;
X	struct passwd	*pw, spw;
X	struct group	*gr;
X
X	if ((pw = getpwuid(getuid())) == NULL) 
X		return -1;
X
X	if ((cp=FindOpt(cmd, "password")) != NULL) {
X		if ((np = getpass("Password:")) == NULL)
X			return -1;
X		if (((cp = GetField(cp, str)) != NULL) && 
X		    ((pw = getpwnam(str)) == NULL))
X			return -1;
X		if (strcmp(crypt(np, pw->pw_passwd), pw->pw_passwd) != 0)
X			return -1;
X	}
X
X	if ((pw = getpwuid(getuid())) == NULL) 
X		return -1;
X
X	if ((cp = FindOpt(cmd, "groups")) != NULL) {
X		for (cp=GetField(cp, str); cp!=NULL; cp=GetField(cp, str)) {
X			if (re_comp(str) != 0)
X				return -1;
X			if ((gr = getgrgid(pw->pw_gid)) != NULL) {
X				if (re_exec(gr->gr_name) == 1) {
X					gr_fail = 0;
X					break;
X				}
X			}
X			setgrent();
X			while ((gr = getgrent()) != NULL) {
X				i = 0;
X				while (gr->gr_mem[i] != NULL) {
X					if (strcmp(gr->gr_mem[i],
X							pw->pw_name)==0)
X						break;
X					i++;
X				}
X				if ((gr->gr_mem[i] != NULL) && 
X				    (re_exec(gr->gr_name) == 1)) {
X						gr_fail = 0;
X						break;
X				}
X			}
X		}
X	}
X	if (gr_fail && ((cp = FindOpt(cmd, "users")) != NULL)) {
X		for (cp=GetField(cp, str); cp!=NULL; cp=GetField(cp, str)) {
X			if (re_comp(str) != 0)
X				return -1;
X			if (re_exec(pw->pw_name) == 1) {
X				uid_fail = 0;
X				break;
X			}
X		}
X	}
X
X	if (gr_fail && uid_fail)
X		return -1;
X	
X	for (i = 0; i < cmd->nopts; i++) {
X		if ((cmd->opts[i][0] != '$') || 
X		    ((cp = index(cmd->opts[i], '=')) == NULL))
X			continue;
X		if (cmd->opts[i][1] != '*') {
X			for (np = cmd->opts[i] + 1; np != cp; np++) 
X				if (!isdigit(*np))
X					break;
X			if (np != cp)
X				continue;
X		} else {
X			if (cmd->opts[i][2] != '=')
X				continue;
X			np = cmd->opts[i] + 3;
X			for (j = num+1; j < argc; j++) {
X				cp = np;
X				for (cp=GetField(cp, str); cp!=NULL; 
X						cp=GetField(cp, str)) {
X					if (re_comp(str) != 0)
X						return -1;
X					if (re_exec(argv[j]) == 1)
X						break;
X				}
X				if (cp == NULL)
X					return -1;
X			}
X		}
X		
X		strncpy(str, cmd->opts[i] + 1, cp - cmd->opts[i] - 1);
X		str[cp - cmd->opts[i] - 1] = '\0';
X		val = atoi(str);
X
X		if (val >= argc)
X			continue;
X		cp++;
X		np = cp;
X		if (reg != NULL) {
X			for (cp=GetField(cp, str); cp!=NULL; 
X					cp=GetField(cp, str)) {
X				regsub(reg, str, buf);
X				if (strcmp(buf, argv[val]) == 0)
X					break;
X			}
X
X			if (cp != NULL)
X				continue;
X
X			free(reg);
X			reg = NULL;
X		}
X
X		if ((reg == NULL) || (cp == NULL)) {
X			cp = np;
X			for (cp=GetField(cp, str); cp!=NULL; 
X					cp=GetField(cp, str)) {
X				if ((reg = regcomp(str)) == NULL) 
X					return -1;
X				if (regexec(reg, argv[val]) == 1)
X					break;
X
X				free(reg);
X				reg = NULL;
X			}
X		}
X
X		if (cp == NULL)
X			return -1;
X	}
X}
X
Go(cmd, num, argc, argv)
cmd_t	*cmd;
int	argc;
int	num;
char	**argv;
X{
X	extern char	**environ;
X	int		i, j, flag, val, len = 0;
X	char		*cp, *np;
X	struct passwd	*pw;
X	struct group	*gr;
X        int             ngroups=0, gidset[256];
X	int		curenv = 0, curarg = 0;
X	char		*new_envp[MAXENV];
X	char		*new_argv[MAXARG];
X	char		str[MAXSTRLEN], buf[4*MAXSTRLEN];
X
X        if ((cp = FindOpt(cmd, "gid")) == NULL) {
X                ;               /* don't have a default */
X        } else {
X                for (; cp!=NULL; cp=GetField(cp, str)) {
X                        if ((gr = getgrnam(cp)) != NULL)
X                                gidset[ngroups++] = gr->gr_gid;
X                }
X                if (ngroups == 0) 
X                        fatal("invalid groups");
X                if (setgroups(ngroups, gidset) < 0)
X                        fatal("setgroups failed");
X                if (setgid(gidset[0]))
X                        fatal("setgid failed");
X        }
X
X	if ((cp = FindOpt(cmd, "uid")) == NULL) {
X                if (setuid(geteuid()) < 0)
X			fatal("Unable to set uid to default", cp);
X	} else {
X		if ((pw = getpwnam(cp)) == NULL) {
X			if (setuid(atoi(cp)) < 0)
X				fatal("Unable to set uid to %s", cp);
X		}
X		if (setuid(pw->pw_uid) < 0)
X			fatal("Unable to set uid to %s", cp);
X	}
X
X	if ((cp = FindOpt(cmd, "umask")) == NULL) {
X		if (umask(0022) < 0)
X			fatal("Unable to set umask to default");
X	} else {
X		if (umask(atov(cp, 8)) < 0)
X			fatal("Unable to set umask to %s", cp);
X	}
X
X	if ((cp = FindOpt(cmd, "chroot")) == NULL) {
X		;		/* don't have a default */
X	} else {
X		if (chroot(cp) < 0)
X			fatal("Unable to chroot to %s", cp);
X	}
X
X	if ((cp = FindOpt(cmd, "dir")) == NULL) {
X		;		/* don't have a default */
X	} else {
X		if (chdir(cp) < 0) 
X			fatal("Unable to chdir to %s", cp);
X	}
X
X	if (FindOpt(cmd, "environment") == NULL) {
X		for (i = 0; i < cmd->nopts; i++) {
X			if (cmd->opts[i][0] != '$')
X				continue;
X			cp = cmd->opts[i] + 1;
X			flag = 0;
X			while ((*cp != '\0') && (*cp != '=')) {
X				if (! isdigit(*cp))
X					flag = 1;
X				cp++;
X			}
X			if (! flag)
X				continue;
X			if (index(cmd->opts[i], '=') != NULL) {
X				new_envp[curenv++] = cmd->opts[i] + 1;
X				continue;
X			}
X			for (j = 0; environ[j] != NULL ; j++) {
X				if ((cp = index(environ[j], '=')) == NULL)
X					continue;
X				if (strncmp(cmd->opts[i] + 1, environ[j],
X						cp - environ[j]) == 0) {
X					new_envp[curenv++] = environ[j];
X					break;
X				}
X			}
X		}
X	} else {
X		for (i = 0; environ[i] != NULL; i++)
X			new_envp[curenv++] = environ[i];
X	}
X	new_envp[curenv] = NULL;
X
X	if (strcmp("MAGIC_SHELL", cmd->args[0]) == 0) {
X		for (i = 0; environ[i] != NULL; i++) 
X			if (strncmp("SHELL=", environ[i], 6) == 0)
X				break;
X
X		if (environ[i] != NULL)
X			new_argv[curarg++] = environ[i] + 6;
X		else {
X			fprintf(stderr,"No shell\n");
X			exit(1);
X		}
X
X		if (argc != 1) {
X			new_argv[curarg++] = "-c";
X
X			for (i = 1; i < argc; i++)
X				len += strlen(argv[i]) + 1;
X
X			if ((cp = (char *)malloc(len + 10)) == NULL) {
X				fprintf(stderr, "Unable to create buffer");
X				exit(1);
X			}
X
X			len = 0;
X			*cp = '\0';
X
X			for (i = 1; i < argc; i++) {
X				strcat(cp, argv[i]);
X				strcat(cp, " ");
X			}
X			new_argv[curarg++] = cp;
X		}
X	} else {
X		for (i = 0; i < cmd->nargs; i++) {
X			np = cmd->args[i];
X
X			while ((cp = index(np, '$')) != NULL) {
X				if ((cp != cmd->args[i]) && (*(cp-1) == '\\'))
X					np = cp + 1;
X				else
X					break;
X			}
X
X			if (cp == NULL) {
X				new_argv[curarg++] = cmd->args[i];
X				continue;
X			}
X			if (*(cp+1) == '*') {
X				for (j = num + 1; j < argc; j++) {
X					new_argv[curarg++] = argv[j];
X				}
X				continue;
X			}
X
X			cp++;
X			np = cp;
X			while (isdigit(*cp))
X				cp++;
X			if ((cp - np) == 0) {
X				new_argv[curarg++] = cmd->args[i];
X				continue;
X			}
X			strncpy(str, np, cp - np);
X			str[cp - np] = '\0';
X			val = atoi(str);
X			buf[0] = '\0';
X			strncpy(buf, cmd->args[i], np - cmd->args[i] - 1);
X			strcat(buf, argv[val]);
X			strcat(buf, cp);
X			new_argv[curarg++] = savestr(buf);
X		}
X	}
X	new_argv[curarg] = NULL;
X
X	if (execve(new_argv[0], new_argv, new_envp) < 0)
X		perror("execve");
X}
X
output(cmd)
cmd_t	*cmd;
X{
X	int	i;
X
X	printf("cmd '%s'\n",cmd->name);
X	printf("\n  args\t");
X	for (i = 0; i < cmd->nargs; i++)
X		printf("'%s' ",cmd->args[i]);
X	printf("\n  opts\t");
X	for (i = 0; i < cmd->nopts; i++)
X		printf("'%s' ",cmd->opts[i]);
X	printf("\n");
X}
END_OF_FILE
if test 11440 -ne `wc -c <'main.c'`; then
    echo shar: \"'main.c'\" unpacked with wrong size!
fi
# end of 'main.c'
fi
if test -f 'op.1' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'op.1'\"
else
echo shar: Extracting \"'op.1'\" \(6076 characters\)
sed "s/^X//" >'op.1' <<'END_OF_FILE'
X.TH OP 1 "December 14, 1989"
X.UC 4
X.SH NAME
op \- operator access
X.SH SYNOPSIS
X.B op 
mnemonic [arg]
X.SH DESCRIPTION
The 
X.I op
tool provides a flexible means for system administrators to grant
trusted users access to certain 
X.B root
operations without having to give them full superuser privileges.
Different sets of users may access different operations, and the
security-related aspects of environment of each
operation can be carefully controlled.
X.PP 
The fields of the entries in 
X.I op.access 
are separated by white space.  Each entry may span several lines and
continues until the next alphanumeric string is found at the beginning of
a lines (which is taken to be the next
X.I mnemonic,
and thus the beginning of a new entry).  Comments may be embedded
beginning with a # character.  Each entry in op
X.I op.access
has the following form:
X.RS
X.DT
X\fImnemonic	command \fR[\fI arg ... \fR]\fI ; \fR[\fI option ... \fR]
X.RE
where the fields are interpreted in the following manner:
X.TP
X.I mnemonic
a unique, alphanumeric identifier for each operator function.
X.TP
X.I command
the full pathname of the executable to be run by
X.I op
when the associated 
X.I mnemonic
is chosen.
X.TP
X.I arg(s)
any arguments, either literal or variable, needed by 
X.I command.
Literal arguments are simply specified directly, like specific command
options (\fB0Gun\fR) or files (\fB/dev/rmt20\fR).  Variable arguments
are specified here as \fB$1, $2 ... $\fR\fIn\fR; these are described
more fully in the options section below. \fB$*\fR indicates any number
trailing arguments.
X.TP
X.I option(s)
a set of optional parameters to specify settings or restoring for the
particular 
X.I mnemonic,
define variable arguments specified for the 
X.I command,
space and are of the form
X.I keyword=value.
The absence of a specific list of values separated by commas, where
appropriate.
There should be no white space in each element of the 
X.I value
string unless quoted.  The
X.I keyword
is any of the following types:
X.TP
X.B uid
Set the user id to the value specified.  The value can be numeric user
ID or a login name.  The default is 
X.B root.
X.TP
X.B gid
Set the group id's to the values specified.  Each value can be a numeric
group ID or a group name.
X.TP
X.B dir
Change the current working directory to the path specified.
X.TP
X.B chroot
Change the root directory to the path specified using 
X.I chroot.
X.TP
X.B umask
Set the file creation umask to the octal value specified.  The default
is to set it to 
X.B 022.
X.TP
X.B groups
Allow any user who belongs to a group listed here to execute this 
X.I op
function.  The default is not to allow any specific group.
X.TP
X.B users
Allow any user listed here to execute this 
X.I op 
function.  The default is not allow any specific users.  You may user
the regular expression .* to indicate that all users may use this
mnemonic.
X.TP
X.B password
Queries the user for a password, if there is no = part the
users own password is asked.
X.TP
X.BI $VAR
where 
X.I VAR
is the name of an environment variable.  The specified environment
case, simply using
X.I $VAR with no = part (as in 
X.B $USER)
means that this environment variable is inherited unchanged from
the caller's shell.
X.TP
X.B environment
Disables the destruction of the users environment.
X.TP
X.B $n
defines the \fIn\fRth variable argument specified in the command 
X.I arg
list.  The value for this type may be a comma-separated list of regular
expressions using \fIegrep\fR(1).  option defines the range of values
allowed for the variable arguments  A variable argument specified as a
command 
X.I arg
but not described in the 
X.I options
section may take on any value.  If an argument does not match any
of its permitted values, then a diagnostic is printed and the
command is not executed.  When using '(' syntax to pass values
to other options, only the next options can use values from
the previous search.
X.TP
X.B $*
is used in the 
X.I options
section to place restriction on the trailing arguments
specified as $* in the
X.I args 
section.  If any of these (possibly many) arguments do not match, then
a diagnostic is printed, and the command is not executed.
X.PP
There can also be a special entry in the file beginning at the first
non-comment line
that can define default values to override the builtin defaults listed
here, yet still be overridden by any entry that wants to redefine any of
the keyword fields described above.  It should have the following format:
X.RS
X.DT
X\fBDEFAULT\fR	\fIkeyword_option\fR
X.RE
where \fIkeyword_option\fR is a \fIkeyword=value\fR string mentioned above
under \fIoptions\fR.
X.PP
It should be noted that if any regular 
X.I mnemonic
entry defines its own
X.I option,
the value given for that entry must explicitly include the item from the
DEFAULT line if the default values is to be included.  That is, the 
X.I options
definitions completely override any
defaults; they do not add to them  In this way, if a value specified on
the DEFAULT line for 
X.B users
or
X.B groups
X(for example) needs to be "erased" without redefining new values
X(that is, we want no users or groups to be allowed to run the mnemonic),
then the default value must be overridden with nothing (as in
X\fBusers=\fR).  For the
X.B users
or
X.B groups
fields, such a null setting has the effect of setting the list of
allowable users or groups to be empty.  For the other keywords (\fR
uid, gid, dir, chroot, \fRand\fB umask\fR), a null setting leaves that
attribute as it is upon invocation of the 
X.I op
program, overriding any defaults.
X.PP
Another note is that if the 
X.I command 
for a 
X.I mnemonic
is 
X.B MAGIC_SHELL
then a shell (using the users $SHELL environment variable) is created, 
if there are arguments in addition to the 
X.I mnemonic
on the command line then the shell is invoked "-c args".
X.SH FILES
X.DT
X/etc/op.access	access control description
X.SH "SEE ALSO"
su(1), chroot(2), egrep(1)
X.SH CREDIT
X.B "Op: A flexible Tool for Restricted Superuser Access",
by
X.I "Tom Christiansen",
CONVEX Computer Corporation,
X.B "Proceedings of the Large Installation Systems Administration III Workshop"
END_OF_FILE
if test 6076 -ne `wc -c <'op.1'`; then
    echo shar: \"'op.1'\" unpacked with wrong size!
fi
# end of 'op.1'
fi
if test -f 'op.access' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'op.access'\"
else
echo shar: Extracting \"'op.access'\" \(1952 characters\)
sed "s/^X//" >'op.access' <<'END_OF_FILE'
X# first, define the site defaults we want to use here
X# we would like the people in 'operator' group to be able to execute
X# almost everything, so it iseasier to put it here than on every line...
X# set up default envariables
X#
DEFAULT groups=operator $USER $TERM $PATH=/usr/ucb:/usr/bin:/bin
X#
X# find out who's filled up the disk; anyone may do this
X#
full	/usr/etc/quot $1; users=.*
X#
X# filesystem backups
X#
daily	/etc/dump 5Gun $1; $1=/,/usr[0-9]*,/project
weekly	/etc/dump 0Gun $1; $1=/,/usr[0-9]*,/project
X#
X# tape handling commands
X# must include 'operator' if we want them to be allowed as well
X#
tape	/etc/tpc $1 $2; groups=tapeopers,operator users=boss
X	$1=enable,disable,stop,restart $2=all,unit[01]
X#
mounted	/etc/tpc mounted unit$1 $2; $1=[0-3]
X#
X# taking the system down
X# $1 shows a good user of regular expression;
X# $2 can be anything, but is required; no instant shutdowns
X#
shutdown	/etc/shutdown -h $1 $2; $1=+[1-9][0-9]*,[0-9]*:[0-9]*
reboot		/etc/shutdown -r $1 $2; $1=+[1-9][0-9]*,[0-9]*:[0-9]*
X#
X# start up disco daemon
disco	/etc/opbin/start_disco ; uid=disco gid=proj dir=/scratch
X		umask=027 groups=geo,disco users=snoopy,linus
X		$USER=disco $SHELL=/bin/shell
X#
X# let certain people mount and unmount the removable drive
X#
rdsmount	/etc/mount $1 $2; groups=operator,swdev,disco
X			users=bob,steve $1=/dev/dd0[a-z] $2=/.*
rdsumount	/etc/umount $1 ; groups=operator,swdev,disco
X			users=bob,steve $1=/dev/dd0[a-z]
X#
X# allow operators to give files away; notice that they
X# must give at least two s, but may give more
X#
chown	/bsd43/bin//chown $1 $2 $*; $1=[a-z0-9][a-z0-9]*
X#
X# permit development personnel to run install
X#
inst	/usr/bin/install -o root -g system $1 $2; groups=devel
X		$2=/bin,/usr/bin,/usr/ucb,/usr/new,/usr/local
X#
nfsmount	/etc/mount -o timeo=100,hard,inter $1 $2; 
X			groups=devel,operator 
X			$1=([a-zA-Z0-9_]*):(.*) $2=/remote/\1\2
X
foo	/bin/cat $1; users=koblas
X
shell	MAGIC_SHELL ; password environment 
END_OF_FILE
if test 1952 -ne `wc -c <'op.access'`; then
    echo shar: \"'op.access'\" unpacked with wrong size!
fi
# end of 'op.access'
fi
if test -f 'regerror.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'regerror.c'\"
else
echo shar: Extracting \"'regerror.c'\" \(224 characters\)
sed "s/^X//" >'regerror.c' <<'END_OF_FILE'
X#include <stdio.h>
X
void
regerror(s)
char *s;
X{
X#ifdef ERRAVAIL
X	error("regexp: %s", s);
X#else
X/*
X	fprintf(stderr, "regexp(3): %s\n", s);
X	exit(1);
X*/
X	return;	  /* let std. egrep handle errors */
X#endif
X	/* NOTREACHED */
X}
END_OF_FILE
if test 224 -ne `wc -c <'regerror.c'`; then
    echo shar: \"'regerror.c'\" unpacked with wrong size!
fi
# end of 'regerror.c'
fi
if test -f 'regexp.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'regexp.c'\"
else
echo shar: Extracting \"'regexp.c'\" \(31149 characters\)
sed "s/^X//" >'regexp.c' <<'END_OF_FILE'
X/*
X * regcomp and regexec -- regsub and regerror are elsewhere
X *
X *	Copyright (c) 1986 by University of Toronto.
X *	Written by Henry Spencer.  Not derived from licensed software.
X *
X *	Permission is granted to anyone to use this software for any
X *	purpose on any computer system, and to redistribute it freely,
X *	subject to the following restrictions:
X *
X *	1. The author is not responsible for the consequences of use of
X *		this software, no matter how awful, even if they arise
X *		from defects in it.
X *
X *	2. The origin of this software must not be misrepresented, either
X *		by explicit claim or by omission.
X *
X *	3. Altered versions must be plainly marked as such, and must not
X *		be misrepresented as being the original software.
X *** THIS IS AN ALTERED VERSION.  It was altered by John Gilmore,
X *** hoptoad!gnu, on 27 Dec 1986, to add \n as an alternative to |
X *** to assist in implementing egrep.
X *** THIS IS AN ALTERED VERSION.  It was altered by John Gilmore,
X *** hoptoad!gnu, on 27 Dec 1986, to add \< and \> for word-matching
X *** as in BSD grep and ex.
X *** THIS IS AN ALTERED VERSION.  It was altered by John Gilmore,
X *** hoptoad!gnu, on 28 Dec 1986, to optimize characters quoted with \.
X *** THIS IS AN ALTERED VERSION.  It was altered by James A. Woods,
X *** ames!jaw, on 19 June 1987, to quash a regcomp() redundancy.
X *
X * Beware that some of this code is subtly aware of the way operator
X * precedence is structured in regular expressions.  Serious changes in
X * regular-expression syntax might require a total rethink.
X */
X#include <stdio.h>
X#include <ctype.h>
X#include <regexp.h>
X#include "regmagic.h"
X
X/*
X * The "internal use only" fields in regexp.h are present to pass info from
X * compile to execute that permits the execute phase to run lots faster on
X * simple cases.  They are:
X *
X * regstart	char that must begin a match; '\0' if none obvious
X * reganch	is the match anchored (at beginning-of-line only)?
X * regmust	string (pointer into program) that match must include, or NULL
X * regmlen	length of regmust string
X *
X * Regstart and reganch permit very fast decisions on suitable starting points
X * for a match, cutting down the work a lot.  Regmust permits fast rejection
X * of lines that cannot possibly match.  The regmust tests are costly enough
X * that regcomp() supplies a regmust only if the r.e. contains something
X * potentially expensive (at present, the only such thing detected is * or +
X * at the start of the r.e., which can involve a lot of backup).  Regmlen is
X * supplied because the test in regexec() needs it and regcomp() is computing
X * it anyway.
X */
X
X/*
X * Structure for regexp "program".  This is essentially a linear encoding
X * of a nondeterministic finite-state machine (aka syntax charts or
X * "railroad normal form" in parsing technology).  Each node is an opcode
X * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
X * all nodes except BRANCH implement concatenation; a "next" pointer with
X * a BRANCH on both ends of it is connecting two alternatives.  (Here we
X * have one of the subtle syntax dependencies:  an individual BRANCH (as
X * opposed to a collection of them) is never concatenated with anything
X * because of operator precedence.)  The operand of some types of node is
X * a literal string; for others, it is a node leading into a sub-FSM.  In
X * particular, the operand of a BRANCH node is the first node of the branch.
X * (NB this is *not* a tree structure:  the tail of the branch connects
X * to the thing following the set of BRANCHes.)  The opcodes are:
X */
X
X/* definition	number	opnd?	meaning */
X#define	END	0	/* no	End of program. */
X#define	BOL	1	/* no	Match "" at beginning of line. */
X#define	EOL	2	/* no	Match "" at end of line. */
X#define	ANY	3	/* no	Match any one character. */
X#define	ANYOF	4	/* str	Match any character in this string. */
X#define	ANYBUT	5	/* str	Match any character not in this string. */
X#define	BRANCH	6	/* node	Match this alternative, or the next... */
X#define	BACK	7	/* no	Match "", "next" ptr points backward. */
X#define	EXACTLY	8	/* str	Match this string. */
X#define	NOTHING	9	/* no	Match empty string. */
X#define	STAR	10	/* node	Match this (simple) thing 0 or more times. */
X#define	PLUS	11	/* node	Match this (simple) thing 1 or more times. */
X#define	WORDA	12	/* no	Match "" at wordchar, where prev is nonword */
X#define	WORDZ	13	/* no	Match "" at nonwordchar, where prev is word */
X#define	OPEN	20	/* no	Mark this point in input as start of #n. */
X			/*	OPEN+1 is number 1, etc. */
X#define	CLOSE	30	/* no	Analogous to OPEN. */
X
X/*
X * Opcode notes:
X *
X * BRANCH	The set of branches constituting a single choice are hooked
X *		together with their "next" pointers, since precedence prevents
X *		anything being concatenated to any individual branch.  The
X *		"next" pointer of the last BRANCH in a choice points to the
X *		thing following the whole choice.  This is also where the
X *		final "next" pointer of each individual branch points; each
X *		branch starts with the operand node of a BRANCH node.
X *
X * BACK		Normal "next" pointers all implicitly point forward; BACK
X *		exists to make loop structures possible.
X *
X * STAR,PLUS	'?', and complex '*' and '+', are implemented as circular
X *		BRANCH structures using BACK.  Simple cases (one character
X *		per match) are implemented with STAR and PLUS for speed
X *		and to minimize recursive plunges.
X *
X * OPEN,CLOSE	...are numbered at compile time.
X */
X
X/*
X * A node is one char of opcode followed by two chars of "next" pointer.
X * "Next" pointers are stored as two 8-bit pieces, high order first.  The
X * value is a positive offset from the opcode of the node containing it.
X * An operand, if any, simply follows the node.  (Note that much of the
X * code generation knows about this implicit relationship.)
X *
X * Using two bytes for the "next" pointer is vast overkill for most things,
X * but allows patterns to get big without disasters.
X */
X#define	OP(p)	(*(p))
X#define	NEXT(p)	(((*((p)+1)&0377)<<8) + (*((p)+2)&0377))
X#define	OPERAND(p)	((p) + 3)
X
X/*
X * See regmagic.h for one further detail of program structure.
X */
X
X
X/*
X * Utility definitions.
X */
X#ifndef CHARBITS
X#define	UCHARAT(p)	((int)*(unsigned char *)(p))
X#else
X#define	UCHARAT(p)	((int)*(p)&CHARBITS)
X#endif
X
X#define	FAIL(m)	{ regerror(m); return(NULL); }
X#define	ISMULT(c)	((c) == '*' || (c) == '+' || (c) == '?')
X
X/*
X * Flags to be passed up and down.
X */
X#define	HASWIDTH	01	/* Known never to match null string. */
X#define	SIMPLE		02	/* Simple enough to be STAR/PLUS operand. */
X#define	SPSTART		04	/* Starts with * or +. */
X#define	WORST		0	/* Worst case. */
X
X/*
X * Global work variables for regcomp().
X */
static char *regparse;		/* Input-scan pointer. */
static int regnpar;		/* () count. */
static char regdummy;
static char *regcode;		/* Code-emit pointer; &regdummy = don't. */
static long regsize;		/* Code size. */
X
X/*
X * Forward declarations for regcomp()'s friends.
X */
X#ifndef STATIC
X#define	STATIC	static
X#endif
STATIC char *reg();
STATIC char *regbranch();
STATIC char *regpiece();
STATIC char *regatom();
STATIC char *regnode();
STATIC char *regnext();
STATIC void regc();
STATIC void reginsert();
STATIC void regtail();
STATIC void regoptail();
X#ifdef STRCSPN
STATIC int strcspn();
X#endif
X
X/*
X - regcomp - compile a regular expression into internal code
X *
X * We can't allocate space until we know how big the compiled form will be,
X * but we can't compile it (and thus know how big it is) until we've got a
X * place to put the code.  So we cheat:  we compile it twice, once with code
X * generation turned off and size counting turned on, and once "for real".
X * This also means that we don't allocate space until we are sure that the
X * thing really will compile successfully, and we never have to move the
X * code and thus invalidate pointers into it.  (Note that it has to be in
X * one piece because free() must be able to free it all.)
X *
X * Beware that the optimization-preparation code in here knows about some
X * of the structure of the compiled regexp.
X */
regexp *
regcomp(exp)
char *exp;
X{
X	register regexp *r;
X	register char *scan;
X	register char *longest;
X	register int len;
X	int flags;
X	extern char *malloc();
X
X	if (exp == NULL)
X		FAIL("NULL argument");
X
X	/* First pass: determine size, legality. */
X	if (exp[0] == '.' && exp[1] == '*') exp += 2;  /* aid grep */
X	regparse = exp;
X	regnpar = 1;
X	regsize = 0L;
X	regcode = &regdummy;
X	regc(MAGIC);
X	if (reg(0, &flags) == NULL)
X		return(NULL);
X
X	/* Small enough for pointer-storage convention? */
X	if (regsize >= 32767L)		/* Probably could be 65535L. */
X		FAIL("regexp too big");
X
X	/* Allocate space. */
X	r = (regexp *)malloc(sizeof(regexp) + (unsigned)regsize);
X	if (r == NULL)
X		FAIL("out of space");
X
X	/* Second pass: emit code. */
X	regparse = exp;
X	regnpar = 1;
X	regcode = r->program;
X	regc(MAGIC);
X	if (reg(0, &flags) == NULL)
X		return(NULL);
X
X	/* Dig out information for optimizations. */
X	r->regstart = '\0';	/* Worst-case defaults. */
X	r->reganch = 0;
X	r->regmust = NULL;
X	r->regmlen = 0;
X	scan = r->program+1;			/* First BRANCH. */
X	if (OP(regnext(scan)) == END) {		/* Only one top-level choice. */
X		scan = OPERAND(scan);
X
X		/* Starting-point info. */
X		if (OP(scan) == EXACTLY)
X			r->regstart = *OPERAND(scan);
X		else if (OP(scan) == BOL)
X			r->reganch++;
X
X		/*
X		 * If there's something expensive in the r.e., find the
X		 * longest literal string that must appear and make it the
X		 * regmust.  Resolve ties in favor of later strings, since
X		 * the regstart check works with the beginning of the r.e.
X		 * and avoiding duplication strengthens checking.  Not a
X		 * strong reason, but sufficient in the absence of others.
X		 */
X		if (flags&SPSTART) {
X			longest = NULL;
X			len = 0;
X			for (; scan != NULL; scan = regnext(scan))
X				if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
X					longest = OPERAND(scan);
X					len = strlen(OPERAND(scan));
X				}
X			r->regmust = longest;
X			r->regmlen = len;
X		}
X	}
X
X	return(r);
X}
X
X/*
X - reg - regular expression, i.e. main body or parenthesized thing
X *
X * Caller must absorb opening parenthesis.
X *
X * Combining parenthesis handling with the base level of regular expression
X * is a trifle forced, but the need to tie the tails of the branches to what
X * follows makes it hard to avoid.
X */
static char *
reg(paren, flagp)
int paren;			/* Parenthesized? */
int *flagp;
X{
X	register char *ret;
X	register char *br;
X	register char *ender;
X	register int parno;
X	int flags;
X
X	*flagp = HASWIDTH;	/* Tentatively. */
X
X	/* Make an OPEN node, if parenthesized. */
X	if (paren) {
X		if (regnpar >= NSUBEXP)
X			FAIL("too many ()");
X		parno = regnpar;
X		regnpar++;
X		ret = regnode(OPEN+parno);
X	} else
X		ret = NULL;
X
X	/* Pick up the branches, linking them together. */
X	br = regbranch(&flags);
X	if (br == NULL)
X		return(NULL);
X	if (ret != NULL)
X		regtail(ret, br);	/* OPEN -> first. */
X	else
X		ret = br;
X	if (!(flags&HASWIDTH))
X		*flagp &= ~HASWIDTH;
X	*flagp |= flags&SPSTART;
X	while (*regparse == '|' || *regparse == '\n') {
X		regparse++;
X		br = regbranch(&flags);
X		if (br == NULL)
X			return(NULL);
X		regtail(ret, br);	/* BRANCH -> BRANCH. */
X		if (!(flags&HASWIDTH))
X			*flagp &= ~HASWIDTH;
X		*flagp |= flags&SPSTART;
X	}
X
X	/* Make a closing node, and hook it on the end. */
X	ender = regnode((paren) ? CLOSE+parno : END);	
X	regtail(ret, ender);
X
X	/* Hook the tails of the branches to the closing node. */
X	for (br = ret; br != NULL; br = regnext(br))
X		regoptail(br, ender);
X
X	/* Check for proper termination. */
X	if (paren && *regparse++ != ')') {
X		FAIL("unmatched ()");
X	} else if (!paren && *regparse != '\0') {
X		if (*regparse == ')') {
X			FAIL("unmatched ()");
X		} else
X			FAIL("junk on end");	/* "Can't happen". */
X		/* NOTREACHED */
X	}
X
X	return(ret);
X}
X
X/*
X - regbranch - one alternative of an | operator
X *
X * Implements the concatenation operator.
X */
static char *
regbranch(flagp)
int *flagp;
X{
X	register char *ret;
X	register char *chain;
X	register char *latest;
X	int flags;
X
X	*flagp = WORST;		/* Tentatively. */
X
X	ret = regnode(BRANCH);
X	chain = NULL;
X	while (*regparse != '\0' && *regparse != ')' &&
X	       *regparse != '\n' && *regparse != '|') {
X		latest = regpiece(&flags);
X		if (latest == NULL)
X			return(NULL);
X		*flagp |= flags&HASWIDTH;
X		if (chain == NULL)	/* First piece. */
X			*flagp |= flags&SPSTART;
X		else
X			regtail(chain, latest);
X		chain = latest;
X	}
X	if (chain == NULL)	/* Loop ran zero times. */
X		(void) regnode(NOTHING);
X
X	return(ret);
X}
X
X/*
X - regpiece - something followed by possible [*+?]
X *
X * Note that the branching code sequences used for ? and the general cases
X * of * and + are somewhat optimized:  they use the same NOTHING node as
X * both the endmarker for their branch list and the body of the last branch.
X * It might seem that this node could be dispensed with entirely, but the
X * endmarker role is not redundant.
X */
static char *
regpiece(flagp)
int *flagp;
X{
X	register char *ret;
X	register char op;
X	register char *next;
X	int flags;
X
X	ret = regatom(&flags);
X	if (ret == NULL)
X		return(NULL);
X
X	op = *regparse;
X	if (!ISMULT(op)) {
X		*flagp = flags;
X		return(ret);
X	}
X
X	if (!(flags&HASWIDTH) && op != '?')
X		FAIL("*+ operand could be empty");
X	*flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
X
X	if (op == '*' && (flags&SIMPLE))
X		reginsert(STAR, ret);
X	else if (op == '*') {
X		/* Emit x* as (x&|), where & means "self". */
X		reginsert(BRANCH, ret);			/* Either x */
X		regoptail(ret, regnode(BACK));		/* and loop */
X		regoptail(ret, ret);			/* back */
X		regtail(ret, regnode(BRANCH));		/* or */
X		regtail(ret, regnode(NOTHING));		/* null. */
X	} else if (op == '+' && (flags&SIMPLE))
X		reginsert(PLUS, ret);
X	else if (op == '+') {
X		/* Emit x+ as x(&|), where & means "self". */
X		next = regnode(BRANCH);			/* Either */
X		regtail(ret, next);
X		regtail(regnode(BACK), ret);		/* loop back */
X		regtail(next, regnode(BRANCH));		/* or */
X		regtail(ret, regnode(NOTHING));		/* null. */
X	} else if (op == '?') {
X		/* Emit x? as (x|) */
X		reginsert(BRANCH, ret);			/* Either x */
X		regtail(ret, regnode(BRANCH));		/* or */
X		next = regnode(NOTHING);		/* null. */
X		regtail(ret, next);
X		regoptail(ret, next);
X	}
X	regparse++;
X	if (ISMULT(*regparse))
X		FAIL("nested *?+");
X
X	return(ret);
X}
X
X/*
X - regatom - the lowest level
X *
X * Optimization:  gobbles an entire sequence of ordinary characters so that
X * it can turn them into a single node, which is smaller to store and
X * faster to run.  Backslashed characters are exceptions, each becoming a
X * separate node; the code is simpler that way and it's not worth fixing.
X */
static char *
regatom(flagp)
int *flagp;
X{
X	register char *ret;
X	int flags;
X
X	*flagp = WORST;		/* Tentatively. */
X
X	switch (*regparse++) {
X	/* FIXME: these chars only have meaning at beg/end of pat? */
X	case '^':
X		ret = regnode(BOL);
X		break;
X	case '$':
X		ret = regnode(EOL);
X		break;
X	case '.':
X		ret = regnode(ANY);
X		*flagp |= HASWIDTH|SIMPLE;
X		break;
X	case '[': {
X			register int class;
X			register int classend;
X
X			if (*regparse == '^') {	/* Complement of range. */
X				ret = regnode(ANYBUT);
X				regparse++;
X			} else
X				ret = regnode(ANYOF);
X			if (*regparse == ']' || *regparse == '-')
X				regc(*regparse++);
X			while (*regparse != '\0' && *regparse != ']') {
X				if (*regparse == '-') {
X					regparse++;
X					if (*regparse == ']' || *regparse == '\0')
X						regc('-');
X					else {
X						class = UCHARAT(regparse-2)+1;
X						classend = UCHARAT(regparse);
X						if (class > classend+1)
X							FAIL("invalid [] range");
X						for (; class <= classend; class++)
X							regc(class);
X						regparse++;
X					}
X				} else
X					regc(*regparse++);
X			}
X			regc('\0');
X			if (*regparse != ']')
X				FAIL("unmatched []");
X			regparse++;
X			*flagp |= HASWIDTH|SIMPLE;
X		}
X		break;
X	case '(':
X		ret = reg(1, &flags);
X		if (ret == NULL)
X			return(NULL);
X		*flagp |= flags&(HASWIDTH|SPSTART);
X		break;
X	case '\0':
X	case '|':
X	case '\n':
X	case ')':
X		FAIL("internal urp");	/* Supposed to be caught earlier. */
X		break;
X	case '?':
X	case '+':
X	case '*':
X		FAIL("?+* follows nothing");
X		break;
X	case '\\':
X		switch (*regparse++) {
X		case '\0':
X			FAIL("trailing \\");
X			break;
X		case '<':
X			ret = regnode(WORDA);
X			break;
X		case '>':
X			ret = regnode(WORDZ);
X			break;
X		/* FIXME: Someday handle \1, \2, ... */
X		default:
X			/* Handle general quoted chars in exact-match routine */
X			goto de_fault;
X		}
X		break;
X	de_fault:
X	default:
X		/*
X		 * Encode a string of characters to be matched exactly.
X		 *
X		 * This is a bit tricky due to quoted chars and due to
X		 * '*', '+', and '?' taking the SINGLE char previous
X		 * as their operand.
X		 *
X		 * On entry, the char at regparse[-1] is going to go
X		 * into the string, no matter what it is.  (It could be
X		 * following a \ if we are entered from the '\' case.)
X		 * 
X		 * Basic idea is to pick up a good char in  ch  and
X		 * examine the next char.  If it's *+? then we twiddle.
X		 * If it's \ then we frozzle.  If it's other magic char
X		 * we push  ch  and terminate the string.  If none of the
X		 * above, we push  ch  on the string and go around again.
X		 *
X		 *  regprev  is used to remember where "the current char"
X		 * starts in the string, if due to a *+? we need to back
X		 * up and put the current char in a separate, 1-char, string.
X		 * When  regprev  is NULL,  ch  is the only char in the
X		 * string; this is used in *+? handling, and in setting
X		 * flags |= SIMPLE at the end.
X		 */
X		{
X			char *regprev;
X			register char ch;
X
X			regparse--;			/* Look at cur char */
X			ret = regnode(EXACTLY);
X			for ( regprev = 0 ; ; ) {
X				ch = *regparse++;	/* Get current char */
X				switch (*regparse) {	/* look at next one */
X
X				default:
X					regc(ch);	/* Add cur to string */
X					break;
X
X				case '.': case '[': case '(':
X				case ')': case '|': case '\n':
X				case '$': case '^':
X				case '\0':
X				/* FIXME, $ and ^ should not always be magic */
X				magic:
X					regc(ch);	/* dump cur char */
X					goto done;	/* and we are done */
X
X				case '?': case '+': case '*':
X					if (!regprev) 	/* If just ch in str, */
X						goto magic;	/* use it */
X					/* End mult-char string one early */
X					regparse = regprev; /* Back up parse */
X					goto done;
X
X				case '\\':
X					regc(ch);	/* Cur char OK */
X					switch (regparse[1]){ /* Look after \ */
X					case '\0':
X					case '<':
X					case '>':
X					/* FIXME: Someday handle \1, \2, ... */
X						goto done; /* Not quoted */
X					default:
X						/* Backup point is \, scan							 * point is after it. */
X						regprev = regparse;
X						regparse++; 
X						continue;	/* NOT break; */
X					}
X				}
X				regprev = regparse;	/* Set backup point */
X			}
X		done:
X			regc('\0');
X			*flagp |= HASWIDTH;
X			if (!regprev)		/* One char? */
X				*flagp |= SIMPLE;
X		}
X		break;
X	}
X
X	return(ret);
X}
X
X/*
X - regnode - emit a node
X */
static char *			/* Location. */
regnode(op)
char op;
X{
X	register char *ret;
X	register char *ptr;
X
X	ret = regcode;
X	if (ret == &regdummy) {
X		regsize += 3;
X		return(ret);
X	}
X
X	ptr = ret;
X	*ptr++ = op;
X	*ptr++ = '\0';		/* Null "next" pointer. */
X	*ptr++ = '\0';
X	regcode = ptr;
X
X	return(ret);
X}
X
X/*
X - regc - emit (if appropriate) a byte of code
X */
static void
regc(b)
char b;
X{
X	if (regcode != &regdummy)
X		*regcode++ = b;
X	else
X		regsize++;
X}
X
X/*
X - reginsert - insert an operator in front of already-emitted operand
X *
X * Means relocating the operand.
X */
static void
reginsert(op, opnd)
char op;
char *opnd;
X{
X	register char *src;
X	register char *dst;
X	register char *place;
X
X	if (regcode == &regdummy) {
X		regsize += 3;
X		return;
X	}
X
X	src = regcode;
X	regcode += 3;
X	dst = regcode;
X	while (src > opnd)
X		*--dst = *--src;
X
X	place = opnd;		/* Op node, where operand used to be. */
X	*place++ = op;
X	*place++ = '\0';
X	*place++ = '\0';
X}
X
X/*
X - regtail - set the next-pointer at the end of a node chain
X */
static void
regtail(p, val)
char *p;
char *val;
X{
X	register char *scan;
X	register char *temp;
X	register int offset;
X
X	if (p == &regdummy)
X		return;
X
X	/* Find last node. */
X	scan = p;
X	for (;;) {
X		temp = regnext(scan);
X		if (temp == NULL)
X			break;
X		scan = temp;
X	}
X
X	if (OP(scan) == BACK)
X		offset = scan - val;
X	else
X		offset = val - scan;
X	*(scan+1) = (offset>>8)&0377;
X	*(scan+2) = offset&0377;
X}
X
X/*
X - regoptail - regtail on operand of first argument; nop if operandless
X */
static void
regoptail(p, val)
char *p;
char *val;
X{
X	/* "Operandless" and "op != BRANCH" are synonymous in practice. */
X	if (p == NULL || p == &regdummy || OP(p) != BRANCH)
X		return;
X	regtail(OPERAND(p), val);
X}
X
X/*
X * regexec and friends
X */
X
X/*
X * Global work variables for regexec().
X */
static char *reginput;		/* String-input pointer. */
static char *regbol;		/* Beginning of input, for ^ check. */
static char **regstartp;	/* Pointer to startp array. */
static char **regendp;		/* Ditto for endp. */
X
X/*
X * Forwards.
X */
STATIC int regtry();
STATIC int regmatch();
STATIC int regrepeat();
X
X#ifdef DEBUG
int regnarrate = 0;
void regdump();
STATIC char *regprop();
X#endif
X
X/*
X - regexec - match a regexp against a string
X */
int
regexec(prog, string)
register regexp *prog;
register char *string;
X{
X	register char *s;
X	extern char *strchr();
X
X	/* Be paranoid... */
X	if (prog == NULL || string == NULL) {
X		regerror("NULL parameter");
X		return(0);
X	}
X
X	/* Check validity of program. */
X	if (UCHARAT(prog->program) != MAGIC) {
X		regerror("corrupted program");
X		return(0);
X	}
X
X	/* If there is a "must appear" string, look for it. */
X	if (prog->regmust != NULL) {
X		s = string;
X		while ((s = strchr(s, prog->regmust[0])) != NULL) {
X			if (strncmp(s, prog->regmust, prog->regmlen) == 0)
X				break;	/* Found it. */
X			s++;
X		}
X		if (s == NULL)	/* Not present. */
X			return(0);
X	}
X
X	/* Mark beginning of line for ^ . */
X	regbol = string;
X
X	/* Simplest case:  anchored match need be tried only once. */
X	if (prog->reganch)
X		return(regtry(prog, string));
X
X	/* Messy cases:  unanchored match. */
X	s = string;
X	if (prog->regstart != '\0')
X		/* We know what char it must start with. */
X		while ((s = strchr(s, prog->regstart)) != NULL) {
X			if (regtry(prog, s))
X				return(1);
X			s++;
X		}
X	else
X		/* We don't -- general case. */
X		do {
X			if (regtry(prog, s))
X				return(1);
X		} while (*s++ != '\0');
X
X	/* Failure. */
X	return(0);
X}
X
X/*
X - regtry - try match at specific point
X */
static int			/* 0 failure, 1 success */
regtry(prog, string)
regexp *prog;
char *string;
X{
X	register int i;
X	register char **sp;
X	register char **ep;
X
X	reginput = string;
X	regstartp = prog->startp;
X	regendp = prog->endp;
X
X	sp = prog->startp;
X	ep = prog->endp;
X	for (i = NSUBEXP; i > 0; i--) {
X		*sp++ = NULL;
X		*ep++ = NULL;
X	}
X	if (regmatch(prog->program + 1)) {
X		prog->startp[0] = string;
X		prog->endp[0] = reginput;
X		return(1);
X	} else
X		return(0);
X}
X
X/*
X - regmatch - main matching routine
X *
X * Conceptually the strategy is simple:  check to see whether the current
X * node matches, call self recursively to see whether the rest matches,
X * and then act accordingly.  In practice we make some effort to avoid
X * recursion, in particular by going through "ordinary" nodes (that don't
X * need to know whether the rest of the match failed) by a loop instead of
X * by recursion.
X */
static int			/* 0 failure, 1 success */
regmatch(prog)
char *prog;
X{
X	register char *scan;	/* Current node. */
X	char *next;		/* Next node. */
X	extern char *strchr();
X
X	scan = prog;
X#ifdef DEBUG
X	if (scan != NULL && regnarrate)
X		fprintf(stderr, "%s(\n", regprop(scan));
X#endif
X	while (scan != NULL) {
X#ifdef DEBUG
X		if (regnarrate)
X			fprintf(stderr, "%s...\n", regprop(scan));
X#endif
X		next = regnext(scan);
X
X		switch (OP(scan)) {
X		case BOL:
X			if (reginput != regbol)
X				return(0);
X			break;
X		case EOL:
X			if (*reginput != '\0')
X				return(0);
X			break;
X		case WORDA:
X			/* Must be looking at a letter, digit, or _ */
X			if ((!isalnum(*reginput)) && *reginput != '_')
X				return(0);
X			/* Prev must be BOL or nonword */
X			if (reginput > regbol &&
X			    (isalnum(reginput[-1]) || reginput[-1] == '_'))
X				return(0);
X			break;
X		case WORDZ:
X			/* Must be looking at non letter, digit, or _ */
X			if (isalnum(*reginput) || *reginput == '_')
X				return(0);
X			/* We don't care what the previous char was */
X			break;
X		case ANY:
X			if (*reginput == '\0')
X				return(0);
X			reginput++;
X			break;
X		case EXACTLY: {
X				register int len;
X				register char *opnd;
X
X				opnd = OPERAND(scan);
X				/* Inline the first character, for speed. */
X				if (*opnd != *reginput)
X					return(0);
X				len = strlen(opnd);
X				if (len > 1 && strncmp(opnd, reginput, len) != 0)
X					return(0);
X				reginput += len;
X			}
X			break;
X		case ANYOF:
X 			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
X				return(0);
X			reginput++;
X			break;
X		case ANYBUT:
X 			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
X				return(0);
X			reginput++;
X			break;
X		case NOTHING:
X			break;
X		case BACK:
X			break;
X		case OPEN+1:
X		case OPEN+2:
X		case OPEN+3:
X		case OPEN+4:
X		case OPEN+5:
X		case OPEN+6:
X		case OPEN+7:
X		case OPEN+8:
X		case OPEN+9: {
X				register int no;
X				register char *save;
X
X				no = OP(scan) - OPEN;
X				save = reginput;
X
X				if (regmatch(next)) {
X					/*
X					 * Don't set startp if some later
X					 * invocation of the same parentheses
X					 * already has.
X					 */
X					if (regstartp[no] == NULL)
X						regstartp[no] = save;
X					return(1);
X				} else
X					return(0);
X			}
X			break;
X		case CLOSE+1:
X		case CLOSE+2:
X		case CLOSE+3:
X		case CLOSE+4:
X		case CLOSE+5:
X		case CLOSE+6:
X		case CLOSE+7:
X		case CLOSE+8:
X		case CLOSE+9: {
X				register int no;
X				register char *save;
X
X				no = OP(scan) - CLOSE;
X				save = reginput;
X
X				if (regmatch(next)) {
X					/*
X					 * Don't set endp if some later
X					 * invocation of the same parentheses
X					 * already has.
X					 */
X					if (regendp[no] == NULL)
X						regendp[no] = save;
X					return(1);
X				} else
X					return(0);
X			}
X			break;
X		case BRANCH: {
X				register char *save;
X
X				if (OP(next) != BRANCH)		/* No choice. */
X					next = OPERAND(scan);	/* Avoid recursion. */
X				else {
X					do {
X						save = reginput;
X						if (regmatch(OPERAND(scan)))
X							return(1);
X						reginput = save;
X						scan = regnext(scan);
X					} while (scan != NULL && OP(scan) == BRANCH);
X					return(0);
X					/* NOTREACHED */
X				}
X			}
X			break;
X		case STAR:
X		case PLUS: {
X				register char nextch;
X				register int no;
X				register char *save;
X				register int min;
X
X				/*
X				 * Lookahead to avoid useless match attempts
X				 * when we know what character comes next.
X				 */
X				nextch = '\0';
X				if (OP(next) == EXACTLY)
X					nextch = *OPERAND(next);
X				min = (OP(scan) == STAR) ? 0 : 1;
X				save = reginput;
X				no = regrepeat(OPERAND(scan));
X				while (no >= min) {
X					/* If it could work, try it. */
X					if (nextch == '\0' || *reginput == nextch)
X						if (regmatch(next))
X							return(1);
X					/* Couldn't or didn't -- back up. */
X					no--;
X					reginput = save + no;
X				}
X				return(0);
X			}
X			break;
X		case END:
X			return(1);	/* Success! */
X			break;
X		default:
X			regerror("memory corruption");
X			return(0);
X			break;
X		}
X
X		scan = next;
X	}
X
X	/*
X	 * We get here only if there's trouble -- normally "case END" is
X	 * the terminating point.
X	 */
X	regerror("corrupted pointers");
X	return(0);
X}
X
X/*
X - regrepeat - repeatedly match something simple, report how many
X */
static int
regrepeat(p)
char *p;
X{
X	register int count = 0;
X	register char *scan;
X	register char *opnd;
X
X	scan = reginput;
X	opnd = OPERAND(p);
X	switch (OP(p)) {
X	case ANY:
X		count = strlen(scan);
X		scan += count;
X		break;
X	case EXACTLY:
X		while (*opnd == *scan) {
X			count++;
X			scan++;
X		}
X		break;
X	case ANYOF:
X		while (*scan != '\0' && strchr(opnd, *scan) != NULL) {
X			count++;
X			scan++;
X		}
X		break;
X	case ANYBUT:
X		while (*scan != '\0' && strchr(opnd, *scan) == NULL) {
X			count++;
X			scan++;
X		}
X		break;
X	default:		/* Oh dear.  Called inappropriately. */
X		regerror("internal foulup");
X		count = 0;	/* Best compromise. */
X		break;
X	}
X	reginput = scan;
X
X	return(count);
X}
X
X/*
X - regnext - dig the "next" pointer out of a node
X */
static char *
regnext(p)
register char *p;
X{
X	register int offset;
X
X	if (p == &regdummy)
X		return(NULL);
X
X	offset = NEXT(p);
X	if (offset == 0)
X		return(NULL);
X
X	if (OP(p) == BACK)
X		return(p-offset);
X	else
X		return(p+offset);
X}
X
X#ifdef DEBUG
X
STATIC char *regprop();
X
X/*
X - regdump - dump a regexp onto stdout in vaguely comprehensible form
X */
void
regdump(r)
regexp *r;
X{
X	register char *s;
X	register char op = EXACTLY;	/* Arbitrary non-END op. */
X	register char *next;
X	extern char *strchr();
X
X
X	s = r->program + 1;
X	while (op != END) {	/* While that wasn't END last time... */
X		op = OP(s);
X		printf("%2d%s", s-r->program, regprop(s));	/* Where, what. */
X		next = regnext(s);
X		if (next == NULL)		/* Next ptr. */
X			printf("(0)");
X		else 
X			printf("(%d)", (s-r->program)+(next-s));
X		s += 3;
X		if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
X			/* Literal string, where present. */
X			while (*s != '\0') {
X				putchar(*s);
X				s++;
X			}
X			s++;
X		}
X		putchar('\n');
X	}
X
X	/* Header fields of interest. */
X	if (r->regstart != '\0')
X		printf("start `%c' ", r->regstart);
X	if (r->reganch)
X		printf("anchored ");
X	if (r->regmust != NULL)
X		printf("must have \"%s\"", r->regmust);
X	printf("\n");
X}
X
X/*
X - regprop - printable representation of opcode
X */
static char *
regprop(op)
char *op;
X{
X	register char *p;
X	static char buf[50];
X
X	(void) strcpy(buf, ":");
X
X	switch (OP(op)) {
X	case BOL:
X		p = "BOL";
X		break;
X	case EOL:
X		p = "EOL";
X		break;
X	case ANY:
X		p = "ANY";
X		break;
X	case ANYOF:
X		p = "ANYOF";
X		break;
X	case ANYBUT:
X		p = "ANYBUT";
X		break;
X	case BRANCH:
X		p = "BRANCH";
X		break;
X	case EXACTLY:
X		p = "EXACTLY";
X		break;
X	case NOTHING:
X		p = "NOTHING";
X		break;
X	case BACK:
X		p = "BACK";
X		break;
X	case END:
X		p = "END";
X		break;
X	case OPEN+1:
X	case OPEN+2:
X	case OPEN+3:
X	case OPEN+4:
X	case OPEN+5:
X	case OPEN+6:
X	case OPEN+7:
X	case OPEN+8:
X	case OPEN+9:
X		sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN);
X		p = NULL;
X		break;
X	case CLOSE+1:
X	case CLOSE+2:
X	case CLOSE+3:
X	case CLOSE+4:
X	case CLOSE+5:
X	case CLOSE+6:
X	case CLOSE+7:
X	case CLOSE+8:
X	case CLOSE+9:
X		sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE);
X		p = NULL;
X		break;
X	case STAR:
X		p = "STAR";
X		break;
X	case PLUS:
X		p = "PLUS";
X		break;
X	case WORDA:
X		p = "WORDA";
X		break;
X	case WORDZ:
X		p = "WORDZ";
X		break;
X	default:
X		regerror("corrupted opcode");
X		break;
X	}
X	if (p != NULL)
X		(void) strcat(buf, p);
X	return(buf);
X}
X#endif
X
X/*
X * The following is provided for those people who do not have strcspn() in
X * their C libraries.  They should get off their butts and do something
X * about it; at least one public-domain implementation of those (highly
X * useful) string routines has been published on Usenet.
X */
X#ifdef STRCSPN
X/*
X * strcspn - find length of initial segment of s1 consisting entirely
X * of characters not from s2
X */
X
static int
strcspn(s1, s2)
char *s1;
char *s2;
X{
X	register char *scan1;
X	register char *scan2;
X	register int count;
X
X	count = 0;
X	for (scan1 = s1; *scan1 != '\0'; scan1++) {
X		for (scan2 = s2; *scan2 != '\0';)	/* ++ moved down. */
X			if (*scan1 == *scan2++)
X				return(count);
X		count++;
X	}
X	return(count);
X}
X#endif
END_OF_FILE
if test 31149 -ne `wc -c <'regexp.c'`; then
    echo shar: \"'regexp.c'\" unpacked with wrong size!
fi
# end of 'regexp.c'
fi
if test -f 'regexp.h' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'regexp.h'\"
else
echo shar: Extracting \"'regexp.h'\" \(574 characters\)
sed "s/^X//" >'regexp.h' <<'END_OF_FILE'
X/*
X * Definitions etc. for regexp(3) routines.
X *
X * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
X * not the System V one.
X */
X#define NSUBEXP  10
typedef struct regexp {
X	char *startp[NSUBEXP];
X	char *endp[NSUBEXP];
X	char regstart;		/* Internal use only. */
X	char reganch;		/* Internal use only. */
X	char *regmust;		/* Internal use only. */
X	int regmlen;		/* Internal use only. */
X	char program[1];	/* Unwarranted chumminess with compiler. */
X} regexp;
X
extern regexp *regcomp();
extern int regexec();
extern void regsub();
extern void regerror();
END_OF_FILE
if test 574 -ne `wc -c <'regexp.h'`; then
    echo shar: \"'regexp.h'\" unpacked with wrong size!
fi
# end of 'regexp.h'
fi
if test -f 'regmagic.h' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'regmagic.h'\"
else
echo shar: Extracting \"'regmagic.h'\" \(153 characters\)
sed "s/^X//" >'regmagic.h' <<'END_OF_FILE'
X/*
X * The first byte of the regexp internal "program" is actually this magic
X * number; the start node begins in the second byte.
X */
X#define	MAGIC	0234
END_OF_FILE
if test 153 -ne `wc -c <'regmagic.h'`; then
    echo shar: \"'regmagic.h'\" unpacked with wrong size!
fi
# end of 'regmagic.h'
fi
if test -f 'regsub.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'regsub.c'\"
else
echo shar: Extracting \"'regsub.c'\" \(1962 characters\)
sed "s/^X//" >'regsub.c' <<'END_OF_FILE'
X/*
X * regsub
X *
X *	Copyright (c) 1986 by University of Toronto.
X *	Written by Henry Spencer.  Not derived from licensed software.
X *
X *	Permission is granted to anyone to use this software for any
X *	purpose on any computer system, and to redistribute it freely,
X *	subject to the following restrictions:
X *
X *	1. The author is not responsible for the consequences of use of
X *		this software, no matter how awful, even if they arise
X *		from defects in it.
X *
X *	2. The origin of this software must not be misrepresented, either
X *		by explicit claim or by omission.
X *
X *	3. Altered versions must be plainly marked as such, and must not
X *		be misrepresented as being the original software.
X */
X#include <stdio.h>
X#include <regexp.h>
X#include "regmagic.h"
X
X#ifndef CHARBITS
X#define	UCHARAT(p)	((int)*(unsigned char *)(p))
X#else
X#define	UCHARAT(p)	((int)*(p)&CHARBITS)
X#endif
X
X/*
X - regsub - perform substitutions after a regexp match
X */
void
regsub(prog, source, dest)
regexp *prog;
char *source;
char *dest;
X{
X	register char *src;
X	register char *dst;
X	register char c;
X	register int no;
X	register int len;
X	extern char *strncpy();
X
X	if (prog == NULL || source == NULL || dest == NULL) {
X		regerror("NULL parm to regsub");
X		return;
X	}
X	if (UCHARAT(prog->program) != MAGIC) {
X		regerror("damaged regexp fed to regsub");
X		return;
X	}
X
X	src = source;
X	dst = dest;
X	while ((c = *src++) != '\0') {
X		if (c == '&')
X			no = 0;
X		else if (c == '\\' && '0' <= *src && *src <= '9')
X			no = *src++ - '0';
X		else
X			no = -1;
X 		if (no < 0) {	/* Ordinary character. */
X 			if (c == '\\' && (*src == '\\' || *src == '&'))
X 				c = *src++;
X 			*dst++ = c;
X 		} else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
X			len = prog->endp[no] - prog->startp[no];
X			(void) strncpy(dst, prog->startp[no], len);
X			dst += len;
X			if (len != 0 && *(dst-1) == '\0') {	/* strncpy hit NUL. */
X				regerror("damaged match string");
X				return;
X			}
X		}
X	}
X	*dst++ = '\0';
X}
END_OF_FILE
if test 1962 -ne `wc -c <'regsub.c'`; then
    echo shar: \"'regsub.c'\" unpacked with wrong size!
fi
# end of 'regsub.c'
fi
if test -f 'vfprintf.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'vfprintf.c'\"
else
echo shar: Extracting \"'vfprintf.c'\" \(1408 characters\)
sed "s/^X//" >'vfprintf.c' <<'END_OF_FILE'
X/*
X * Copyright (c) 1988 Regents of the University of California.
X * All rights reserved.
X *
X * Redistribution and use in source and binary forms are permitted
X * provided that the above copyright notice and this paragraph are
X * duplicated in all such forms and that any documentation,
X * advertising materials, and other materials related to such
X * distribution and use acknowledge that the software was developed
X * by the University of California, Berkeley.  The name of the
X * University may not be used to endorse or promote products derived
X * from this software without specific prior written permission.
X * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
X * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
X * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
X */
X
X#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)vfprintf.c	5.2 (Berkeley) 6/27/88";
X#endif /* LIBC_SCCS and not lint */
X
X#include <stdio.h>
X#include <varargs.h>
X
int
vfprintf(iop, fmt, ap)
X	FILE *iop;
X	char *fmt;
X	va_list ap;
X{
X	int len;
X	char localbuf[BUFSIZ];
X
X	if (iop->_flag & _IONBF) {
X		iop->_flag &= ~_IONBF;
X		iop->_ptr = iop->_base = localbuf;
X		len = _doprnt(fmt, ap, iop);
X		(void) fflush(iop);
X		iop->_flag |= _IONBF;
X		iop->_base = NULL;
X		iop->_bufsiz = 0;
X		iop->_cnt = 0;
X	} else
X		len = _doprnt(fmt, ap, iop);
X
X	return (ferror(iop) ? EOF : len);
X}
END_OF_FILE
if test 1408 -ne `wc -c <'vfprintf.c'`; then
    echo shar: \"'vfprintf.c'\" unpacked with wrong size!
fi
# end of 'vfprintf.c'
fi
echo shar: End of archive 1 \(of 1\).
cp /dev/null ark1isdone
MISSING=""
for I in 1 ; do
    if test ! -f ark${I}isdone ; then
	MISSING="${MISSING} ${I}"
    fi
done
if test "${MISSING}" = "" ; then
    echo You have the archive.
    rm -f ark[1-9]isdone
else
    echo You still need to unpack the following archives:
    echo "        " ${MISSING}
fi
##  End of shell archive.
exit 0