/*
 * main.c -- Code generator and main program for gawk.
 */

/*
 * Copyright (C) 1986, 1988, 1989, 1991-2021,
 * the Free Software Foundation, Inc.
 *
 * This file is part of GAWK, the GNU implementation of the
 * AWK Programming Language.
 *
 * GAWK is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GAWK is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/* FIX THIS BEFORE EVERY RELEASE: */
#define UPDATE_YEAR	2021

#include "awk.h"
#include "getopt.h"

#ifdef HAVE_MCHECK_H
#include <mcheck.h>
#endif

#ifdef HAVE_LIBSIGSEGV
#include <sigsegv.h>
#else
typedef void *stackoverflow_context_t;
/* the argument to this macro is purposely not used */
#define sigsegv_install_handler(catchsegv) signal(SIGSEGV, catchsig)
/* define as 0 rather than empty so that (void) cast on it works */
#define stackoverflow_install_handler(catchstackoverflow, extra_stack, STACK_SIZE) 0
#endif

#define DEFAULT_PROFILE		"awkprof.out"	/* where to put profile */
#define DEFAULT_VARFILE		"awkvars.out"	/* where to put vars */
#define DEFAULT_PREC		53
#define DEFAULT_ROUNDMODE	"N"		/* round to nearest */

static const char *varfile = DEFAULT_VARFILE;
const char *command_file = NULL;	/* debugger commands */

static void usage(int exitval, FILE *fp) ATTRIBUTE_NORETURN;
static void copyleft(void) ATTRIBUTE_NORETURN;
static void cmdline_fs(char *str);
static void init_args(int argc0, int argc, const char *argv0, char **argv);
static void init_vars(void);
static NODE *load_environ(void);
static NODE *load_procinfo(void);
static void catchsig(int sig);
#ifdef HAVE_LIBSIGSEGV
static int catchsegv(void *fault_address, int serious);
static void catchstackoverflow(int emergency, stackoverflow_context_t scp);
#endif
static void nostalgia(void) ATTRIBUTE_NORETURN;
static void version(void) ATTRIBUTE_NORETURN;
static void init_fds(void);
static void init_groupset(void);
static void save_argv(int, char **);
static const char *platform_name();

/* These nodes store all the special variables AWK uses */
NODE *ARGC_node, *ARGIND_node, *ARGV_node, *BINMODE_node, *CONVFMT_node;
static NODE *ENVIRON_node;
NODE *ERRNO_node, *FIELDWIDTHS_node, *FILENAME_node;
NODE *FNR_node, *FPAT_node, *FS_node, *IGNORECASE_node, *LINT_node;
NODE *NF_node, *NR_node, *OFMT_node, *OFS_node, *ORS_node, *PROCINFO_node;
NODE *RLENGTH_node, *RSTART_node, *RS_node, *RT_node, *SUBSEP_node;
NODE *PREC_node, *ROUNDMODE_node;
NODE *TEXTDOMAIN_node;

long NF;
long NR;
long FNR;
int BINMODE;
bool IGNORECASE;
char *OFS;
char *ORS;
char *OFMT;
char *TEXTDOMAIN;

/*
 * CONVFMT is a convenience pointer for the current number to string format.
 * We must supply an initial value to avoid recursion problems of
 *	set_CONVFMT -> fmt_index -> force_string: gets NULL CONVFMT
 * Fun, fun, fun, fun.
 */
const char *CONVFMT = "%.6g";

NODE *Nnull_string;		/* The global null string */

#if defined(HAVE_LOCALE_H)
struct lconv loc;		/* current locale */
static void init_locale(struct lconv *l);
#endif /* defined(HAVE_LOCALE_H) */

/* The name the program was invoked under, for error messages */
const char *myname;

/* A block of AWK code to be run */
INSTRUCTION *code_block = NULL;

char **d_argv;			/* saved argv for debugger restarting */
/*
 * List of rules and functions with first and last instruction (source_line)
 * information; used for profiling and debugging.
 */
INSTRUCTION *rule_list;

int exit_val = EXIT_SUCCESS;		/* exit value */

#if defined(YYDEBUG) || defined(GAWKDEBUG)
extern int yydebug;
#endif

SRCFILE *srcfiles; /* source files */

/*
 * structure to remember variable pre-assignments
 */
struct pre_assign {
	enum assign_type { PRE_ASSIGN = 1, PRE_ASSIGN_FS } type;
	char *val;
};

static struct pre_assign *preassigns = NULL;	/* requested via -v or -F */
static long numassigns = -1;			/* how many of them */

static bool disallow_var_assigns = false;	/* true for --exec */

static void add_preassign(enum assign_type type, char *val);

static void parse_args(int argc, char **argv);
static void set_locale_stuff(void);
static bool stopped_early = false;

enum do_flag_values do_flags = DO_FLAG_NONE;
bool do_itrace = false;			/* provide simple instruction trace */
bool do_optimize = true;		/* apply default optimizations */
static int do_nostalgia = false;	/* provide a blast from the past */
static int do_binary = false;		/* hands off my data! */
static int do_version = false;		/* print version info */
static const char *locale = "";		/* default value to setlocale */
static const char *locale_dir = LOCALEDIR;	/* default locale dir */

int use_lc_numeric = false;	/* obey locale for decimal point */

int gawk_mb_cur_max;		/* MB_CUR_MAX value, see comment in main() */

FILE *output_fp;		/* default gawk output, can be redirected in the debugger */
bool output_is_tty = false;	/* control flushing of output */

/* default format for strftime(), available via PROCINFO */
const char def_strftime_format[] = "%a %b %e %H:%M:%S %Z %Y";

extern const char *version_string;

#if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
GETGROUPS_T *groupset;		/* current group set */
int ngroups;			/* size of said set */
#endif

void (*lintfunc)(const char *mesg, ...) = r_warning;

/* Sorted by long option name! */
static const struct option optab[] = {
	{ "assign",		required_argument,	NULL,	'v' },
	{ "bignum",		no_argument,		NULL,	'M' },
	{ "characters-as-bytes", no_argument,		& do_binary,	 'b' },
	{ "copyright",		no_argument,		NULL,	'C' },
	{ "debug",		optional_argument,	NULL,	'D' },
	{ "dump-variables",	optional_argument,	NULL,	'd' },
	{ "exec",		required_argument,	NULL,	'E' },
	{ "field-separator",	required_argument,	NULL,	'F' },
	{ "file",		required_argument,	NULL,	'f' },
	{ "gen-pot",		no_argument,		NULL,	'g' },
	{ "help",		no_argument,		NULL,	'h' },
	{ "include",		required_argument,	NULL,	'i' },
	{ "lint",		optional_argument,	NULL,	'L' },
	{ "lint-old",		no_argument,		NULL,	't' },
	{ "load",		required_argument,	NULL,	'l' },
#if defined(LOCALEDEBUG)
	{ "locale",		required_argument,	NULL,	'Z' },
#endif
	{ "non-decimal-data",	no_argument,		NULL,	'n' },
	{ "no-optimize",	no_argument,		NULL,	's' },
	{ "nostalgia",		no_argument,		& do_nostalgia,	1 },
	{ "optimize",		no_argument,		NULL,	'O' },
#if defined(YYDEBUG) || defined(GAWKDEBUG)
	{ "parsedebug",		no_argument,		NULL,	'Y' },
#endif
	{ "posix",		no_argument,		NULL,	'P' },
	{ "pretty-print",	optional_argument,	NULL,	'o' },
	{ "profile",		optional_argument,	NULL,	'p' },
	{ "re-interval",	no_argument,		NULL,	'r' },
	{ "sandbox",		no_argument,		NULL, 	'S' },
	{ "source",		required_argument,	NULL,	'e' },
	{ "trace",		no_argument,		NULL,	'I' },
	{ "traditional",	no_argument,		NULL,	'c' },
	{ "use-lc-numeric",	no_argument,		& use_lc_numeric, 1 },
	{ "version",		no_argument,		& do_version, 'V' },
	{ NULL, 0, NULL, '\0' }
};

/* main --- process args, parse program, run it, clean up */

int
main(int argc, char **argv)
{
	int i;
	char *extra_stack;
	bool have_srcfile = false;
	SRCFILE *s;
	char *cp;
#if defined(LOCALEDEBUG)
	const char *initial_locale;
#endif

	/* do these checks early */
	if (getenv("TIDYMEM") != NULL)
		do_flags |= DO_TIDY_MEM;

#ifdef HAVE_MCHECK_H
#ifdef HAVE_MTRACE
	if (do_tidy_mem)
		mtrace();
#endif /* HAVE_MTRACE */
#endif /* HAVE_MCHECK_H */

	myname = gawk_name(argv[0]);
	os_arg_fixup(&argc, &argv); /* emulate redirection, expand wildcards */

	if (argc < 2)
		usage(EXIT_FAILURE, stderr);

	if ((cp = getenv("GAWK_LOCALE_DIR")) != NULL)
		locale_dir = cp;

#if defined(F_GETFL) && defined(O_APPEND)
	// 1/2018: This is needed on modern BSD systems so that the
	// inplace tests pass. I think it's a bug in those kernels
	// but let's just work around it anyway.
	int flags = fcntl(fileno(stderr), F_GETFL, NULL);
	if (flags >= 0 && (flags & O_APPEND) == 0) {
		flags |= O_APPEND;
		(void) fcntl(fileno(stderr), F_SETFL, flags);
	}
#endif

#if defined(LOCALEDEBUG)
	initial_locale = locale;
#endif
	set_locale_stuff();

	(void) signal(SIGFPE, catchsig);
#ifdef SIGBUS
	(void) signal(SIGBUS, catchsig);
#endif

	/*
	 * Ignore SIGPIPE so that writes to pipes that fail don't
	 * kill the process but instead return -1 and set errno.
	 * That lets us print a fatal message instead of dieing suddenly.
	 *
	 * Note that this requires ignoring EPIPE when writing and
	 * flushing stdout/stderr in other parts of the program. E.g.,
	 *
	 * 	gawk 'BEGIN { print "hi" }' | exit
	 *
	 * should not give us "broken pipe" messages --- mainly because
	 * it did not do so in the past and people would complain.
	 */
	ignore_sigpipe();

	(void) sigsegv_install_handler(catchsegv);
#define STACK_SIZE (16*1024)
	emalloc(extra_stack, char *, STACK_SIZE, "main");
	(void) stackoverflow_install_handler(catchstackoverflow, extra_stack, STACK_SIZE);
#undef STACK_SIZE

	/* initialize the null string */
	Nnull_string = make_string("", 0);

	/* Robustness: check that file descriptors 0, 1, 2 are open */
	init_fds();

	/* init array handling. */
	array_init();

	/* init the symbol tables */
	init_symbol_table();

	output_fp = stdout;

	/* initialize global (main) execution context */
	push_context(new_context());

	parse_args(argc, argv);

#if defined(LOCALEDEBUG)
	if (locale != initial_locale)
		set_locale_stuff();
#endif

	/*
	 * In glibc, MB_CUR_MAX is actually a function.  This value is
	 * tested *a lot* in many speed-critical places in gawk. Caching
	 * this value once makes a speed difference.
	 */
	gawk_mb_cur_max = MB_CUR_MAX;

	/* init the cache for checking bytes if they're characters */
	init_btowc_cache();

	/* set up the single byte case table */
	if (gawk_mb_cur_max == 1)
		load_casetable();

	if (do_nostalgia)
		nostalgia();

	/* check for POSIXLY_CORRECT environment variable */
	if (! do_posix && getenv("POSIXLY_CORRECT") != NULL) {
		do_flags |= DO_POSIX;
		if (do_lint)
			lintwarn(
	_("environment variable `POSIXLY_CORRECT' set: turning on `--posix'"));
	}

	// Checks for conflicting command-line arguments.
	if (do_posix) {
		use_lc_numeric = true;
		if (do_traditional)	/* both on command line */
			warning(_("`--posix' overrides `--traditional'"));
		else
			do_flags |= DO_TRADITIONAL;
			/*
			 * POSIX compliance also implies
			 * no GNU extensions either.
			 */
	}

	if (do_traditional && do_non_decimal_data) {
		do_flags &= ~DO_NON_DEC_DATA;
		warning(_("`--posix'/`--traditional' overrides `--non-decimal-data'"));
	}

	if (do_binary) {
		if (do_posix)
			warning(_("`--posix' overrides `--characters-as-bytes'"));
		else {
			gawk_mb_cur_max = 1;	/* hands off my data! */
#if defined(LC_ALL)
			setlocale(LC_ALL, "C");
#endif
		}
	}

	if (do_lint) {
		if (os_is_setuid())
			lintwarn(_("running %s setuid root may be a security problem"), myname);
		if (do_intervals)
			lintwarn(_("The -r/--re-interval options no longer have any effect"));
	}

	if (do_debug)	/* Need to register the debugger pre-exec hook before any other */
		init_debug();

#ifdef HAVE_MPFR
	/* Set up MPFR defaults, and register pre-exec hook to process arithmetic opcodes */
	if (do_mpfr)
		init_mpfr(DEFAULT_PREC, DEFAULT_ROUNDMODE);
#endif

	/* load group set */
	init_groupset();

#ifdef HAVE_MPFR
	if (do_mpfr) {
		mpz_init(Nnull_string->mpg_i);
		Nnull_string->flags = (MALLOC|STRCUR|STRING|MPZN|NUMCUR|NUMBER);
	} else
#endif
	{
		Nnull_string->numbr = 0.0;
		Nnull_string->flags = (MALLOC|STRCUR|STRING|NUMCUR|NUMBER);
	}

	/*
	 * Tell the regex routines how they should work.
	 * Do this before initializing variables, since
	 * they could want to do a regexp compile.
	 */
	resetup();

	/* Set up the special variables */
	init_vars();

	/* Set up the field variables */
	init_fields();

	/* Now process the pre-assignments */
	int dash_v_errs = 0;	// bad stuff for -v
	for (i = 0; i <= numassigns; i++) {
		if (preassigns[i].type == PRE_ASSIGN)
			dash_v_errs += (arg_assign(preassigns[i].val, true) == false);
		else	/* PRE_ASSIGN_FS */
			cmdline_fs(preassigns[i].val);
		efree(preassigns[i].val);
	}

	if (preassigns != NULL)
		efree(preassigns);

	if ((BINMODE & BINMODE_INPUT) != 0)
		if (os_setbinmode(fileno(stdin), O_BINARY) == -1)
			fatal(_("cannot set binary mode on stdin: %s"), strerror(errno));
	if ((BINMODE & BINMODE_OUTPUT) != 0) {
		if (os_setbinmode(fileno(stdout), O_BINARY) == -1)
			fatal(_("cannot set binary mode on stdout: %s"), strerror(errno));
		if (os_setbinmode(fileno(stderr), O_BINARY) == -1)
			fatal(_("cannot set binary mode on stderr: %s"), strerror(errno));
	}

#ifdef GAWKDEBUG
	setbuf(stdout, (char *) NULL);	/* make debugging easier */
#endif
	if (os_isatty(fileno(stdout)))
		output_is_tty = true;

	/* initialize API before loading extension libraries */
	init_ext_api();

	/* load extension libs */
	for (s = srcfiles->next; s != srcfiles; s = s->next) {
		if (s->stype == SRC_EXTLIB)
			load_ext(s->fullpath);
		else if (s->stype != SRC_INC)
			have_srcfile = true;
	}

	/* do version check after extensions are loaded to get extension info */
	if (do_version)
		version();

	/* No -f or --source options, use next arg */
	if (! have_srcfile) {
		if (optind > argc - 1 || stopped_early) /* no args left or no program */
			usage(EXIT_FAILURE, stderr);
		(void) add_srcfile(SRC_CMDLINE, argv[optind], srcfiles, NULL, NULL);
		optind++;
	}

	/* Select the interpreter routine */
	init_interpret();

	init_args(optind, argc,
			do_posix ? argv[0] : myname,
			argv);

#if defined(LC_NUMERIC)
	/*
	 * FRAGILE!  CAREFUL!
	 * Pre-initing the variables with arg_assign() can change the
	 * locale.  Force it to C before parsing the program.
	 */
	setlocale(LC_NUMERIC, "C");
#endif
	/* Read in the program */
	if (parse_program(& code_block, false) != 0 || dash_v_errs > 0)
		exit(EXIT_FAILURE);

	if (do_intl)
		exit(EXIT_SUCCESS);

	set_current_namespace(awk_namespace);

	install_builtins();

	if (do_lint)
		shadow_funcs();

	if (do_lint && code_block->nexti->opcode == Op_atexit)
		lintwarn(_("no program text at all!"));

	load_symbols();

	if (do_profile)
		init_profiling_signals();

#if defined(LC_NUMERIC)
	/*
	 * See comment above about using locale's decimal point.
	 *
	 * 10/2005:
	 * Bitter experience teaches us that most people the world over
	 * use period as the decimal point, not whatever their locale
	 * uses.  Thus, only use the locale's decimal point if being
	 * posixly anal-retentive.
	 *
	 * 7/2007:
	 * Be a little bit kinder. Allow the --use-lc-numeric option
	 * to also use the local decimal point. This avoids the draconian
	 * strictness of POSIX mode if someone just wants to parse their
	 * data using the local decimal point.
	 */
	if (use_lc_numeric)
		setlocale(LC_NUMERIC, locale);
#endif

	init_io();
	output_fp = stdout;

	if (do_debug)
		debug_prog(code_block);
	else if (do_pretty_print && ! do_profile)
		;	/* run pretty printer only. */
	else
		interpret(code_block);

	if (do_pretty_print) {
		set_current_namespace(awk_namespace);
		dump_prog(code_block);
		dump_funcs();
	}

	if (do_dump_vars)
		dump_vars(varfile);

#ifdef HAVE_MPFR
	if (do_mpfr)
		cleanup_mpfr();
#endif

	if (do_tidy_mem)
		release_all_vars();

	/* keep valgrind happier */
	if (extra_stack)
		efree(extra_stack);

	final_exit(exit_val);
	return exit_val;	/* to suppress warnings */
}

/* add_preassign --- add one element to preassigns */

static void
add_preassign(enum assign_type type, char *val)
{
	static long alloc_assigns;		/* for how many are allocated */

#define INIT_SRC 4

	++numassigns;

	if (preassigns == NULL) {
		emalloc(preassigns, struct pre_assign *,
			INIT_SRC * sizeof(struct pre_assign), "add_preassign");
		alloc_assigns = INIT_SRC;
	} else if (numassigns >= alloc_assigns) {
		alloc_assigns *= 2;
		erealloc(preassigns, struct pre_assign *,
			alloc_assigns * sizeof(struct pre_assign), "add_preassigns");
	}
	preassigns[numassigns].type = type;
	preassigns[numassigns].val = estrdup(val, strlen(val));

#undef INIT_SRC
}

/* usage --- print usage information and exit */

static void
usage(int exitval, FILE *fp)
{
	/* Not factoring out common stuff makes it easier to translate. */
	fprintf(fp, _("Usage: %s [POSIX or GNU style options] -f progfile [--] file ...\n"),
		myname);
	fprintf(fp, _("Usage: %s [POSIX or GNU style options] [--] %cprogram%c file ...\n"),
			myname, quote, quote);

	/* GNU long options info. This is too many options. */

	fputs(_("POSIX options:\t\tGNU long options: (standard)\n"), fp);
	fputs(_("\t-f progfile\t\t--file=progfile\n"), fp);
	fputs(_("\t-F fs\t\t\t--field-separator=fs\n"), fp);
	fputs(_("\t-v var=val\t\t--assign=var=val\n"), fp);
	fputs(_("Short options:\t\tGNU long options: (extensions)\n"), fp);
	fputs(_("\t-b\t\t\t--characters-as-bytes\n"), fp);
	fputs(_("\t-c\t\t\t--traditional\n"), fp);
	fputs(_("\t-C\t\t\t--copyright\n"), fp);
	fputs(_("\t-d[file]\t\t--dump-variables[=file]\n"), fp);
	fputs(_("\t-D[file]\t\t--debug[=file]\n"), fp);
	fputs(_("\t-e 'program-text'\t--source='program-text'\n"), fp);
	fputs(_("\t-E file\t\t\t--exec=file\n"), fp);
	fputs(_("\t-g\t\t\t--gen-pot\n"), fp);
	fputs(_("\t-h\t\t\t--help\n"), fp);
	fputs(_("\t-i includefile\t\t--include=includefile\n"), fp);
	fputs(_("\t-I\t\t\t--trace\n"), fp);
	fputs(_("\t-l library\t\t--load=library\n"), fp);
	/*
	 * TRANSLATORS: the "fatal", "invalid" and "no-ext" here are literal
	 * values, they should not be translated. Thanks.
	 */
	fputs(_("\t-L[fatal|invalid|no-ext]\t--lint[=fatal|invalid|no-ext]\n"), fp);
	fputs(_("\t-M\t\t\t--bignum\n"), fp);
	fputs(_("\t-N\t\t\t--use-lc-numeric\n"), fp);
	fputs(_("\t-n\t\t\t--non-decimal-data\n"), fp);
	fputs(_("\t-o[file]\t\t--pretty-print[=file]\n"), fp);
	fputs(_("\t-O\t\t\t--optimize\n"), fp);
	fputs(_("\t-p[file]\t\t--profile[=file]\n"), fp);
	fputs(_("\t-P\t\t\t--posix\n"), fp);
	fputs(_("\t-r\t\t\t--re-interval\n"), fp);
	fputs(_("\t-s\t\t\t--no-optimize\n"), fp);
	fputs(_("\t-S\t\t\t--sandbox\n"), fp);
	fputs(_("\t-t\t\t\t--lint-old\n"), fp);
	fputs(_("\t-V\t\t\t--version\n"), fp);
#ifdef NOSTALGIA
	fputs(_("\t-W nostalgia\t\t--nostalgia\n"), fp);
#endif
#ifdef GAWKDEBUG
	fputs(_("\t-Y\t\t\t--parsedebug\n"), fp);
#endif
#ifdef GAWKDEBUG
	fputs(_("\t-Z locale-name\t\t--locale=locale-name\n"), fp);
#endif

	/* This is one string to make things easier on translators. */
	/* TRANSLATORS: --help output (end)
	   no-wrap */
	fputs(_("\nTo report bugs in Enhanced Gawk, send e-mail to \n\
Kaz Kylheku <kaz at kylheku dot com>.\n\
PLEASE do NOT try to report bugs or seek support in the original\n\
bug-gawk mailing list, unless you can reproduce the issue with the\n\
unmodified gawk program. Also do not report bugs in the comp.lang.awk\n\
Usenet newsgroup, or in web forum such as Stack Overflow.\n\n"), fp);

	/* ditto */
	fputs(_("gawk is a pattern scanning and processing language.\n\
By default it reads standard input and writes standard output.\n\n"), fp);

	/* ditto */
	fprintf(fp, _("Examples:\n\t%s '{ sum += $1 }; END { print sum }' file\n\
\t%s -F: '{ print $1 }' /etc/passwd\n"), myname, myname);

	fflush(fp);

	if (ferror(fp)) {
		os_maybe_set_errno();

		/* don't warn about stdout/stderr if EPIPE, but do error exit */
		if (errno == EPIPE)
			die_via_sigpipe();

		if (fp == stdout)
			warning(_("error writing standard output: %s"), strerror(errno));
		else if (fp == stderr)
			warning(_("error writing standard error: %s"), strerror(errno));

		// some other problem than SIGPIPE
		exit(EXIT_FAILURE);
	}

	exit(exitval);
}

/* copyleft --- print out the short GNU copyright information */

static void
copyleft()
{
	static const char blurb_part1[] =
	  N_("Copyright (C) 1989, 1991-%d Free Software Foundation.\n\
\n\
This program is free software; you can redistribute it and/or modify\n\
it under the terms of the GNU General Public License as published by\n\
the Free Software Foundation; either version 3 of the License, or\n\
(at your option) any later version.\n\
\n");
	static const char blurb_part2[] =
	  N_("This program is distributed in the hope that it will be useful,\n\
but WITHOUT ANY WARRANTY; without even the implied warranty of\n\
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n\
GNU General Public License for more details.\n\
\n");
	static const char blurb_part3[] =
	  N_("You should have received a copy of the GNU General Public License\n\
along with this program. If not, see http://www.gnu.org/licenses/.\n");

	/* multiple blurbs are needed for some brain dead compilers. */
	printf(_(blurb_part1), UPDATE_YEAR);	/* Last update year */
	fputs(_(blurb_part2), stdout);
	fputs(_(blurb_part3), stdout);
	fflush(stdout);

	if (ferror(stdout)) {
		os_maybe_set_errno();

		/* don't warn about stdout if EPIPE, but do error exit */
		if (errno != EPIPE)
			warning(_("error writing standard output: %s"), strerror(errno));
		exit(EXIT_FAILURE);
	}

	exit(EXIT_SUCCESS);
}

/* cmdline_fs --- set FS from the command line */

static void
cmdline_fs(char *str)
{
	NODE **tmp;

	tmp = &FS_node->var_value;
	unref(*tmp);
	/*
	 * Only if in full compatibility mode check for the stupid special
	 * case so -F\t works as documented in awk book even though the shell
	 * hands us -Ft.  Bleah!
	 *
	 * Thankfully, POSIX didn't propagate this "feature".
	 */
	if (str[0] == 't' && str[1] == '\0') {
		if (do_lint)
			lintwarn(_("-Ft does not set FS to tab in POSIX awk"));
		if (do_traditional && ! do_posix)
			str[0] = '\t';
	}

	*tmp = make_str_node(str, strlen(str), SCAN); /* do process escapes */
	set_FS();
}

/* init_args --- set up ARGV from stuff on the command line */

static void
init_args(int argc0, int argc, const char *argv0, char **argv)
{
	int i, j;
	NODE *sub, *val;
	NODE *shadow_node = NULL;

	ARGV_node = install_symbol(estrdup("ARGV", 4), Node_var_array);
	sub = make_number(0.0);
	val = make_string(argv0, strlen(argv0));
	val->flags |= USER_INPUT;
	assoc_set(ARGV_node, sub, val);

	if (do_sandbox) {
		shadow_node = make_array();
		sub = make_string(argv0, strlen(argv0));
		val = make_number(0.0);
		assoc_set(shadow_node, sub, val);
	}


	for (i = argc0, j = 1; i < argc; i++, j++) {
		sub = make_number((AWKNUM) j);
		val = make_string(argv[i], strlen(argv[i]));
		val->flags |= USER_INPUT;
		assoc_set(ARGV_node, sub, val);

		if (do_sandbox) {
			sub = make_string(argv[i], strlen(argv[i]));
			val = make_number(0.0);
			assoc_set(shadow_node, sub, val);
		}
	}

	ARGC_node = install_symbol(estrdup("ARGC", 4), Node_var);
	ARGC_node->var_value = make_number((AWKNUM) j);

	if (do_sandbox)
		init_argv_array(ARGV_node, shadow_node);
}


/*
 * Set all the special variables to their initial values.
 * Note that some of the variables that have set_FOO routines should
 * *N*O*T* have those routines called upon initialization, and thus
 * they have NULL entries in that field. This is notably true of FS
 * and IGNORECASE.
 */

struct varinit {
	NODE **spec;
	const char *name;
	const char *strval;
	AWKNUM numval;
	Func_ptr update;
	Func_ptr assign;
	bool do_assign;
	int flags;
#define NO_INSTALL	0x01
#define NON_STANDARD	0x02
#define NOT_OFF_LIMITS	0x04	/* may be accessed by extension function */
};

static const struct varinit varinit[] = {
{NULL,		"ARGC",		NULL,	0,  NULL, NULL,	false, NO_INSTALL },
{&ARGIND_node,	"ARGIND",	NULL,	0,  NULL, NULL,	false, NON_STANDARD },
{NULL,		"ARGV",		NULL,	0,  NULL, NULL,	false, NO_INSTALL },
{&BINMODE_node,	"BINMODE",	NULL,	0,  NULL, set_BINMODE,	false, NON_STANDARD },
{&CONVFMT_node,	"CONVFMT",	"%.6g",	0,  NULL, set_CONVFMT,true, 	0 },
{NULL,		"ENVIRON",	NULL,	0,  NULL, NULL,	false, NO_INSTALL },
{&ERRNO_node,	"ERRNO",	"",	0,  NULL, NULL,	false, NON_STANDARD },
{&FIELDWIDTHS_node, "FIELDWIDTHS", "",	0,  NULL, set_FIELDWIDTHS,	false, NON_STANDARD },
{&FILENAME_node, "FILENAME",	"",	0,  NULL, NULL,	false, 0 },
{&FNR_node,	"FNR",		NULL,	0,  update_FNR, set_FNR,	true, 0 },
{&FS_node,	"FS",		" ",	0,  NULL, set_FS,	false, 0 },
{&FPAT_node,	"FPAT",		"[^[:space:]]+", 0,  NULL, set_FPAT,	false, NON_STANDARD },
{&IGNORECASE_node, "IGNORECASE", NULL,	0,  NULL, set_IGNORECASE,	false, NON_STANDARD },
{&LINT_node,	"LINT",		NULL,	0,  NULL, set_LINT,	false, NON_STANDARD },
{&PREC_node,	"PREC",		NULL,	DEFAULT_PREC,	NULL,	set_PREC,	false,	NON_STANDARD},
{&NF_node,	"NF",		NULL,	-1, update_NF, set_NF,	false, 0 },
{&NR_node,	"NR",		NULL,	0,  update_NR, set_NR,	true, 0 },
{&OFMT_node,	"OFMT",		"%.6g",	0,  NULL, set_OFMT,	true, 0 },
{&OFS_node,	"OFS",		" ",	0,  NULL, set_OFS,	true, 0 },
{&ORS_node,	"ORS",		"\n",	0,  NULL, set_ORS,	true, 0 },
{NULL,		"PROCINFO",	NULL,	0,  NULL, NULL,	false, NO_INSTALL | NON_STANDARD | NOT_OFF_LIMITS },
{&RLENGTH_node, "RLENGTH",	NULL,	0,  NULL, NULL,	false, 0 },
{&ROUNDMODE_node, "ROUNDMODE",	DEFAULT_ROUNDMODE,	0,  NULL, set_ROUNDMODE,	false, NON_STANDARD },
{&RS_node,	"RS",		"\n",	0,  NULL, set_RS,	true, 0 },
{&RSTART_node,	"RSTART",	NULL,	0,  NULL, NULL,	false, 0 },
{&RT_node,	"RT",		"",	0,  NULL, NULL,	false, NON_STANDARD },
{&SUBSEP_node,	"SUBSEP",	"\034",	0,  NULL, set_SUBSEP,	true, 0 },
{&TEXTDOMAIN_node,	"TEXTDOMAIN",	"messages",	0,  NULL, set_TEXTDOMAIN,	true, NON_STANDARD },
{0,		NULL,		NULL,	0,  NULL, NULL,	false, 0 },
};

/* init_vars --- actually initialize everything in the symbol table */

static void
init_vars()
{
	const struct varinit *vp;
	NODE *n;

	for (vp = varinit; vp->name != NULL; vp++) {
		if ((vp->flags & NO_INSTALL) != 0)
			continue;
		n = *(vp->spec) = install_symbol(estrdup(vp->name, strlen(vp->name)), Node_var);
		if (vp->strval != NULL)
			n->var_value = make_string(vp->strval, strlen(vp->strval));
		else
			n->var_value = make_number(vp->numval);
		n->var_assign = (Func_ptr) vp->assign;
		n->var_update = (Func_ptr) vp->update;
		if (vp->do_assign)
			(*(vp->assign))();
	}

	/* Load PROCINFO and ENVIRON */
	if (! do_traditional)
		load_procinfo();
	load_environ();
}

/* path_environ --- put path variable into environment if not already there */

static void
path_environ(const char *pname, const char *dflt)
{
	const char *val;
	NODE **aptr;
	NODE *tmp;

	tmp = make_string(pname, strlen(pname));
	/*
	 * On VMS, environ[] only holds a subset of what getenv() can
	 * find, so look AWKPATH up before resorting to default path.
	 */
	val = getenv(pname);
	if (val == NULL || *val == '\0')
		val = dflt;
	aptr = assoc_lookup(ENVIRON_node, tmp);
	/*
	 * If original value was the empty string, set it to
	 * the default value.
	 */
	if ((*aptr)->stlen == 0) {
		unref(*aptr);
		*aptr = make_string(val, strlen(val));
	}

	unref(tmp);
}

/* load_environ --- populate the ENVIRON array */

static NODE *
load_environ()
{
#if ! (defined(VMS) && defined(__DECC))
	extern char **environ;
#endif
	char *var, *val;
	int i;
	NODE *sub, *newval;
	static bool been_here = false;

	if (been_here)
		return ENVIRON_node;

	been_here = true;

	ENVIRON_node = install_symbol(estrdup("ENVIRON", 7), Node_var_array);
	for (i = 0; environ[i] != NULL; i++) {
		static char nullstr[] = "";

		var = environ[i];
		val = strchr(var, '=');
		if (val != NULL)
			*val++ = '\0';
		else
			val = nullstr;
		sub = make_string(var, strlen(var));
		newval = make_string(val, strlen(val));
		newval->flags |= USER_INPUT;
		assoc_set(ENVIRON_node, sub, newval);

		/* restore '=' so that system() gets a valid environment */
		if (val != nullstr)
			*--val = '=';
	}
	/*
	 * Put AWKPATH and AWKLIBPATH into ENVIRON if not already there.
	 * This allows querying it from within awk programs.
	 *
	 * October 2014:
	 * If their values are "", override with the default values;
	 * since 2.10 AWKPATH used default value if environment's
	 * value was "".
	 */
	path_environ("AWKPATH", defpath);
	path_environ("AWKLIBPATH", deflibpath);

	/* set up array functions */
	init_env_array(ENVIRON_node);

	return ENVIRON_node;
}

/* load_procinfo_argv --- populate PROCINFO["argv"] */

static void
load_procinfo_argv()
{
	NODE *sub;
	NODE *val;
	NODE *argv_array;
	int i;

	// build the sub-array first
	getnode(argv_array);
 	memset(argv_array, '\0', sizeof(NODE));  /* valgrind wants this */
	null_array(argv_array);
	argv_array->parent_array = PROCINFO_node;
	argv_array->vname = estrdup("argv", 4);
	for (i = 0; d_argv[i] != NULL; i++) {
		sub = make_number(i);
		val = make_string(d_argv[i], strlen(d_argv[i]));
		assoc_set(argv_array, sub, val);
	}

	// hook it into PROCINFO
	sub = make_string("argv", 4);
	assoc_set(PROCINFO_node, sub, argv_array);
}

/* load_procinfo --- populate the PROCINFO array */

static NODE *
load_procinfo()
{
#if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
	int i;
#endif
#if (defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0) || defined(HAVE_MPFR)
	char name[100];
#endif
	AWKNUM value;
	static bool been_here = false;

	if (been_here)
		return PROCINFO_node;

	been_here = true;

	PROCINFO_node = install_symbol(estrdup("PROCINFO", 8), Node_var_array);

	update_PROCINFO_str("version", VERSION);
	update_PROCINFO_str("strftime", def_strftime_format);
	update_PROCINFO_str("platform", platform_name());

#ifdef HAVE_MPFR
	sprintf(name, "GNU MPFR %s", mpfr_get_version());
	update_PROCINFO_str("mpfr_version", name);
	sprintf(name, "GNU MP %s", gmp_version);
	update_PROCINFO_str("gmp_version", name);
	update_PROCINFO_num("prec_max", MPFR_PREC_MAX);
	update_PROCINFO_num("prec_min", MPFR_PREC_MIN);
#endif

#ifdef DYNAMIC
	update_PROCINFO_num("api_major", GAWK_API_MAJOR_VERSION);
	update_PROCINFO_num("api_minor", GAWK_API_MINOR_VERSION);
#endif

#ifdef GETPGRP_VOID
#define getpgrp_arg() /* nothing */
#else
#define getpgrp_arg() getpid()
#endif

	value = getpgrp(getpgrp_arg());
	update_PROCINFO_num("pgrpid", value);

	/*
	 * Could put a lot of this into a table, but then there's
	 * portability problems declaring all the functions. So just
	 * do it the slow and stupid way. Sigh.
	 */

	value = getpid();
	update_PROCINFO_num("pid", value);

	value = getppid();
	update_PROCINFO_num("ppid", value);

	value = getuid();
	update_PROCINFO_num("uid", value);

	value = geteuid();
	update_PROCINFO_num("euid", value);

	value = getgid();
	update_PROCINFO_num("gid", value);

	value = getegid();
	update_PROCINFO_num("egid", value);

	update_PROCINFO_str("FS", current_field_sep_str());

#if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
	for (i = 0; i < ngroups; i++) {
		sprintf(name, "group%d", i + 1);
		value = groupset[i];
		update_PROCINFO_num(name, value);
	}
	if (groupset) {
		efree(groupset);
		groupset = NULL;
	}
#endif
	load_procinfo_argv();
	return PROCINFO_node;
}

/* is_std_var --- return true if a variable is a standard variable */

int
is_std_var(const char *var)
{
	const struct varinit *vp;

	for (vp = varinit; vp->name != NULL; vp++) {
		if (strcmp(vp->name, var) == 0) {
			if ((do_traditional || do_posix) && (vp->flags & NON_STANDARD) != 0)
				return false;

			return true;
		}
	}

	return false;
}

/*
 * is_off_limits_var --- return true if a variable is off limits
 * 			to extension functions
 */

int
is_off_limits_var(const char *var)
{
	const struct varinit *vp;

	for (vp = varinit; vp->name != NULL; vp++) {
		if (strcmp(vp->name, var) == 0)
			return ((vp->flags & NOT_OFF_LIMITS) == 0);
	}

	return false;
}

/* get_spec_varname --- return the name of a special variable
	with the given assign or update routine.
*/

const char *
get_spec_varname(Func_ptr fptr)
{
	const struct varinit *vp;

	if (! fptr)
		return NULL;
	for (vp = varinit; vp->name != NULL; vp++) {
		if (vp->assign == fptr || vp->update == fptr)
			return vp->name;
	}
	return NULL;
}


/* arg_assign --- process a command-line assignment */

int
arg_assign(char *arg, bool initing)
{
	char *cp, *cp2;
	bool badvar;
	NODE *var;
	NODE *it;
	NODE **lhs;
	long save_FNR;

	if (! initing && disallow_var_assigns)
		return false;	/* --exec */

	cp = strchr(arg, '=');

	if (cp == NULL) {
		if (! initing)
			return false;	/* This is file name, not assignment. */

		fprintf(stderr,
			_("%s: `%s' argument to `-v' not in `var=value' form\n\n"),
			myname, arg);
		usage(EXIT_FAILURE, stderr);
	}

	*cp++ = '\0';

	/* avoid false source indications in a fatal message */
	source = NULL;
	sourceline = 0;
	save_FNR = FNR;
	FNR = 0;

	/* first check that the variable name has valid syntax */
	badvar = false;
	if (! is_letter((unsigned char) arg[0]))
		badvar = true;
	else
		for (cp2 = arg+1; *cp2; cp2++)
			if (! is_identchar((unsigned char) *cp2) && *cp2 != ':') {
				badvar = true;
				break;
			}

	if (badvar) {
		if (initing)
			fatal(_("`%s' is not a legal variable name"), arg);

		if (do_lint)
			lintwarn(_("`%s' is not a variable name, looking for file `%s=%s'"),
				arg, arg, cp);

		goto done;
	}

	// Assigning a string or typed regex

	if (! validate_qualified_name(arg)) {
		badvar = true;
		goto done;
	}

	if (check_special(arg) >= 0)
		fatal(_("cannot use gawk builtin `%s' as variable name"), arg);

	if (! initing) {
		var = lookup(arg);
		if (var != NULL && var->type == Node_func)
			fatal(_("cannot use function `%s' as variable name"), arg);
	}

	cp2 = cp + strlen(cp) - 1;	// end char
	if (! do_traditional
	    && strlen(cp) >= 3		// '@/' doesn't do it.
	    && cp[0] == '@' && cp[1] == '/' && *cp2 == '/') {
		// typed regex
		size_t len = strlen(cp) - 3;

		ezalloc(cp2, char *, len + 1, "arg_assign");
		memcpy(cp2, cp + 2, len);

		it = make_typed_regex(cp2, len);
		// fall through to variable setup
	} else {
		// string assignment

		// POSIX disallows any newlines inside strings
		// The scanner handles that for program files.
		// We have to check here for strings passed to -v.
		if (do_posix && strchr(cp, '\n') != NULL)
			fatal(_("POSIX does not allow physical newlines in string values"));

		/*
		 * BWK awk expands escapes inside assignments.
		 * This makes sense, so we do it too.
		 * In addition, remove \-<newline> as in scanning.
		 */
		it = make_str_node(cp, strlen(cp), SCAN | ELIDE_BACK_NL);
		it->flags |= USER_INPUT;
#ifdef LC_NUMERIC
		/*
		 * See comment above about locale decimal point.
		 */
		if (do_posix)
			setlocale(LC_NUMERIC, "C");
#endif /* LC_NUMERIC */
		(void) force_number(it);
#ifdef LC_NUMERIC
		if (do_posix)
			setlocale(LC_NUMERIC, locale);
#endif /* LC_NUMERIC */
	}

	/*
	 * since we are restoring the original text of ARGV later,
	 * need to copy the variable name part if we don't want
	 * name like v=abc instead of just v in var->vname
	 */

	cp2 = estrdup(arg, cp - arg);	/* var name */

	var = variable(0, cp2, Node_var);
	if (var == NULL)	/* error */
		final_exit(EXIT_FATAL);

	if (var->type == Node_var && var->var_update)
		var->var_update();
	lhs = get_lhs(var, false);
	unref(*lhs);
	*lhs = it;
	/* check for set_FOO() routine */
	if (var->type == Node_var && var->var_assign)
		var->var_assign();

done:
	if (! initing)
		*--cp = '=';	/* restore original text of ARGV */
	FNR = save_FNR;
	return ! badvar;
}

/* catchsig --- catch signals */

static void
catchsig(int sig)
{
	if (sig == SIGFPE) {
		fatal(_("floating point exception"));
	} else if (sig == SIGSEGV
#ifdef SIGBUS
	        || sig == SIGBUS
#endif
	) {
		if (errcount > 0)	// assume a syntax error corrupted our data structures
			exit(EXIT_FATAL);

		set_loc(__FILE__, __LINE__);
		msg(_("fatal error: internal error"));
		/* fatal won't abort() if not compiled for debugging */
		// GLIBC 2.27 doesn't necessarily flush on abort. Sigh.
		fflush(NULL);
		abort();
	} else
		cant_happen("unexpected signal, number %s", strsignal(sig));
	/* NOTREACHED */
}

#ifdef HAVE_LIBSIGSEGV
/* catchsegv --- for use with libsigsegv */

static int
catchsegv(void *fault_address, int serious)
{
	if (errcount > 0)	// assume a syntax error corrupted our data structures
		exit(EXIT_FATAL);

	set_loc(__FILE__, __LINE__);
	msg(_("fatal error: internal error: segfault"));
	fflush(NULL);
	abort();
	/*NOTREACHED*/
	return 0;
}

/* catchstackoverflow --- for use with libsigsegv */

static void
catchstackoverflow(int emergency, stackoverflow_context_t scp)
{
	set_loc(__FILE__, __LINE__);
	msg(_("fatal error: internal error: stack overflow"));
	fflush(NULL);
	abort();
	/*NOTREACHED*/
	return;
}
#endif /* HAVE_LIBSIGSEGV */

/* nostalgia --- print the famous error message and die */

static void
nostalgia()
{
	/*
	 * N.B.: This string is not gettextized, on purpose.
	 * So there.
	 */
	fprintf(stderr, "awk: bailing out near line 1\n");
	fflush(stderr);
	abort();
}

/* version --- print version message */

static void
version()
{
	printf("%s", version_string);
#ifdef DYNAMIC
	printf(", API: %d.%d", GAWK_API_MAJOR_VERSION, GAWK_API_MINOR_VERSION);
#endif
#ifdef HAVE_MPFR
	printf(" (GNU MPFR %s, GNU MP %s)", mpfr_get_version(), gmp_version);
#endif
	printf("\n");
	print_ext_versions();

	/*
	 * Per GNU coding standards, print copyright info,
	 * then exit successfully, do nothing else.
	 */
	copyleft();
	exit(EXIT_SUCCESS);
}

/* init_fds --- check for 0, 1, 2, open on /dev/null if possible */

static void
init_fds()
{
	struct stat sbuf;
	int fd;
	int newfd;
	char const *const opposite_mode[] = {"w", "r", "r"};

	/* maybe no stderr, don't bother with error mesg */
	for (fd = 0; fd <= 2; fd++) {
		if (fstat(fd, &sbuf) < 0) {
#if MAKE_A_HEROIC_EFFORT
			if (do_lint)
				lintwarn(_("no pre-opened fd %d"), fd);
#endif
			newfd = devopen("/dev/null", opposite_mode[fd]);
			/* turn off some compiler warnings "set but not used" */
			newfd += 0;
#ifdef MAKE_A_HEROIC_EFFORT
			if (do_lint && newfd < 0)
				lintwarn(_("could not pre-open /dev/null for fd %d"), fd);
#endif
		}
	}
}

/* init_groupset --- initialize groupset */

static void
init_groupset()
{
#if defined(HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
#ifdef GETGROUPS_NOT_STANDARD
	/* For systems that aren't standards conformant, use old way. */
	ngroups = NGROUPS_MAX;
#else
	/*
	 * If called with 0 for both args, return value is
	 * total number of groups.
	 */
	ngroups = getgroups(0, NULL);
#endif
	/* If an error or no groups, just give up and get on with life. */
	if (ngroups <= 0)
		return;

	/* fill in groups */
	emalloc(groupset, GETGROUPS_T *, ngroups * sizeof(GETGROUPS_T), "init_groupset");

	ngroups = getgroups(ngroups, groupset);
	/* same thing here, give up but keep going */
	if (ngroups == -1) {
		efree(groupset);
		ngroups = 0;
		groupset = NULL;
	}
#endif
}

/* estrdup --- duplicate a string */

char *
estrdup(const char *str, size_t len)
{
	char *s;
	emalloc(s, char *, len + 1, "estrdup");
	memcpy(s, str, len);
	s[len] = '\0';
	return s;
}

#if defined(HAVE_LOCALE_H)

/* init_locale --- initialize locale info. */

/*
 * On some operating systems, the pointers in the struct returned
 * by localeconv() can become dangling pointers after a call to
 * setlocale().  So we do a deep copy.
 *
 * Thanks to KIMURA Koichi <kimura.koichi@canon.co.jp>.
 */

static void
init_locale(struct lconv *l)
{
	struct lconv *t;

	t = localeconv();
	*l = *t;
	l->thousands_sep = estrdup(t->thousands_sep, strlen(t->thousands_sep));
	l->decimal_point = estrdup(t->decimal_point, strlen(t->decimal_point));
	l->grouping = estrdup(t->grouping, strlen(t->grouping));
	l->int_curr_symbol = estrdup(t->int_curr_symbol, strlen(t->int_curr_symbol));
	l->currency_symbol = estrdup(t->currency_symbol, strlen(t->currency_symbol));
	l->mon_decimal_point = estrdup(t->mon_decimal_point, strlen(t->mon_decimal_point));
	l->mon_thousands_sep = estrdup(t->mon_thousands_sep, strlen(t->mon_thousands_sep));
	l->mon_grouping = estrdup(t->mon_grouping, strlen(t->mon_grouping));
	l->positive_sign = estrdup(t->positive_sign, strlen(t->positive_sign));
	l->negative_sign = estrdup(t->negative_sign, strlen(t->negative_sign));
}
#endif /* LOCALE_H */

/* save_argv --- save argv array */

static void
save_argv(int argc, char **argv)
{
	int i;

	emalloc(d_argv, char **, (argc + 1) * sizeof(char *), "save_argv");
	for (i = 0; i < argc; i++)
		d_argv[i] = estrdup(argv[i], strlen(argv[i]));
	d_argv[argc] = NULL;
}

/*
 * update_global_values --- make sure the symbol table has correct values.
 * Called from the grammar before dumping values.
 *
 * Also called when accessing through SYMTAB, and from api_sym_lookup().
 */

void
update_global_values()
{
	const struct varinit *vp;

	for (vp = varinit; vp->name; vp++) {
		if (vp->update != NULL)
			vp->update();
	}
}

/* getenv_long --- read a long value (>= 0) from an environment var. */

long
getenv_long(const char *name)
{
	const char *val;
	long newval;
	if ((val = getenv(name)) != NULL && isdigit((unsigned char) *val)) {
		for (newval = 0; *val && isdigit((unsigned char) *val); val++)
			newval = (newval * 10) + *val - '0';
		return newval;
	}
	return -1;
}

/* parse_args --- do the getopt_long thing */

static void
parse_args(int argc, char **argv)
{
	/*
	 * The + on the front tells GNU getopt not to rearrange argv.
	 */
	const char *optlist = "+F:f:v:W;bcCd::D::e:E:ghi:Il:L::nNo::Op::MPrSstVYZ:";
	int old_optind;
	int c;
	char *scan;
	char *src;

	/* we do error messages ourselves on invalid options */
	opterr = false;

	/* copy argv before getopt gets to it; used to restart the debugger */
	save_argv(argc, argv);

	/* option processing. ready, set, go! */
	for (optopt = 0, old_optind = 1;
	     (c = getopt_long(argc, argv, optlist, optab, NULL)) != EOF;
	     optopt = 0, old_optind = optind) {
		if (do_posix)
			opterr = true;

		switch (c) {
		case 'F':
			add_preassign(PRE_ASSIGN_FS, optarg);
			break;

		case 'E':
			disallow_var_assigns = true;
			/* fall through */
		case 'f':
			/*
			 * Allow multiple -f options.
			 * This makes function libraries real easy.
			 * Most of the magic is in the scanner.
			 *
			 * The following is to allow for whitespace at the end
			 * of a #! /bin/gawk line in an executable file
			 */
			scan = optarg;
			if (argv[optind-1] != optarg)
				while (isspace((unsigned char) *scan))
					scan++;
			src = (*scan == '\0' ? argv[optind++] : optarg);
			(void) add_srcfile((src && src[0] == '-' && src[1] == '\0') ?
					SRC_STDIN : SRC_FILE,
					src, srcfiles, NULL, NULL);

			break;

		case 'v':
			add_preassign(PRE_ASSIGN, optarg);
			break;

		case 'b':
			do_binary = true;
			break;

		case 'c':
			do_flags |= DO_TRADITIONAL;
			break;

		case 'C':
			copyleft();
			break;

		case 'd':
			do_flags |= DO_DUMP_VARS;
			if (optarg != NULL && optarg[0] != '\0')
				varfile = optarg;
			break;

		case 'D':
			do_flags |= DO_DEBUG;
			if (optarg != NULL && optarg[0] != '\0')
				command_file = optarg;
			break;

		case 'e':
			if (optarg[0] == '\0')
				warning(_("empty argument to `-e/--source' ignored"));
			else
				(void) add_srcfile(SRC_CMDLINE, optarg, srcfiles, NULL, NULL);
			break;

		case 'g':
			do_flags |= DO_INTL;
			break;

		case 'h':
			/* write usage to stdout, per GNU coding stds */
			usage(EXIT_SUCCESS, stdout);
			break;

		case 'i':
			(void) add_srcfile(SRC_INC, optarg, srcfiles, NULL, NULL);
			break;

		case 'I':
			do_itrace = true;
			break;

		case 'l':
			(void) add_srcfile(SRC_EXTLIB, optarg, srcfiles, NULL, NULL);
			break;

#ifndef NO_LINT
		case 'L':
			do_flags |= (DO_LINT_ALL|DO_LINT_EXTENSIONS);
			if (optarg != NULL) {
				if (strcmp(optarg, "fatal") == 0)
					lintfunc = r_fatal;
				else if (strcmp(optarg, "invalid") == 0) {
					do_flags &= ~DO_LINT_ALL;
					do_flags |= DO_LINT_INVALID;
				}
				else if (strcmp(optarg, "no-ext") == 0) {
					do_flags &= ~DO_LINT_EXTENSIONS;
				}
			}
			break;

		case 't':
			do_flags |= DO_LINT_OLD;
			break;
#else
		case 'L':
		case 't':
			break;
#endif

		case 'n':
			do_flags |= DO_NON_DEC_DATA;
			break;

		case 'N':
			use_lc_numeric = true;
			break;

		case 'O':
			do_optimize = true;
			break;

		case 'p':
			if (do_pretty_print)
				warning(_("`--profile' overrides `--pretty-print'"));
			do_flags |= DO_PROFILE;
			/* fall through */
		case 'o':
			if (c == 'o' && do_profile)
				warning(_("`--profile' overrides `--pretty-print'"));
			do_flags |= DO_PRETTY_PRINT;
			if (optarg != NULL)
				set_prof_file(optarg);
			else
				set_prof_file(DEFAULT_PROFILE);
			break;

		case 'M':
#ifdef HAVE_MPFR
			do_flags |= DO_MPFR;
#else
			warning(_("-M ignored: MPFR/GMP support not compiled in"));
#endif
			break;

		case 'P':
			do_flags |= DO_POSIX;
			break;

		case 'r':
			// This no longer has any effect. It remains for the
			// lint check in main().
			do_flags |= DO_INTERVALS;
 			break;

		case 's':
			do_optimize = false;
			break;

		case 'S':
			do_flags |= DO_SANDBOX;
			break;

		case 'V':
			do_version = true;
			break;

		case 'W':       /* gawk specific options - now in getopt_long */
			fprintf(stderr, _("%s: option `-W %s' unrecognized, ignored\n"),
				argv[0], optarg);
			break;

		case 0:
			/*
			 * getopt_long found an option that sets a variable
			 * instead of returning a letter. Do nothing, just
			 * cycle around for the next one.
			 */
			break;

		case 'Y':
		case 'Z':
#if defined(YYDEBUG) || defined(GAWKDEBUG)
			if (c == 'Y') {
				yydebug = 2;
				break;
			}
#endif
#if defined(LOCALEDEBUG)
			if (c == 'Z') {
				locale = optarg;
				break;
			}
#endif
			/* if not debugging, fall through */
		case '?':
		default:
			/*
			 * If not posix, an unrecognized option stops argument
			 * processing so that it can go into ARGV for the awk
			 * program to see. This makes use of ``#! /bin/gawk -f''
			 * easier.
			 *
			 * However, it's never simple. If optopt is set,
			 * an option that requires an argument didn't get the
			 * argument. We care because if opterr is 0, then
			 * getopt_long won't print the error message for us.
			 */
			if (! do_posix
			    && (optopt == '\0' || strchr(optlist, optopt) == NULL)) {
				/*
				 * can't just do optind--. In case of an
				 * option with >= 2 letters, getopt_long
				 * won't have incremented optind.
				 */
				optind = old_optind;
				stopped_early = true;
				goto out;
			} else if (optopt != '\0') {
				/* Use POSIX required message format */
				fprintf(stderr,
					_("%s: option requires an argument -- %c\n"),
					myname, optopt);
				usage(EXIT_FAILURE, stderr);
			}
			/* else
				let getopt print error message for us */
			break;
		}
		if (c == 'E')	/* --exec ends option processing */
			break;
	}
out:
	do_optimize = (do_optimize && ! do_pretty_print);

	return;
}

/* set_locale_stuff --- setup the locale stuff */

static void
set_locale_stuff(void)
{
#if defined(LC_CTYPE)
	setlocale(LC_CTYPE, locale);
#endif
#if defined(LC_COLLATE)
	setlocale(LC_COLLATE, locale);
#endif
#if defined(LC_MESSAGES)
	setlocale(LC_MESSAGES, locale);
#endif
#if defined(LC_NUMERIC) && defined(HAVE_LOCALE_H)
	/*
	 * Force the issue here.  According to POSIX 2001, decimal
	 * point is used for parsing source code and for command-line
	 * assignments and the locale value for processing input,
	 * number to string conversion, and printing output.
	 *
	 * 10/2005 --- see below also; we now only use the locale's
	 * decimal point if do_posix in effect.
	 *
	 * 9/2007:
	 * This is a mess. We need to get the locale's numeric info for
	 * the thousands separator for the %'d flag.
	 */
	setlocale(LC_NUMERIC, locale);
	init_locale(& loc);
	setlocale(LC_NUMERIC, "C");
#endif
#if defined(LC_TIME)
	setlocale(LC_TIME, locale);
#endif

	/* These must be done after calling setlocale */
	(void) bindtextdomain(PACKAGE, locale_dir);
	(void) textdomain(PACKAGE);
}

/* platform_name --- return the platform name */

static const char *
platform_name()
{
	// Cygwin and Mac OS X count as POSIX
#if defined(__VMS)
	return "vms";
#elif defined(__MINGW32__)
	return "mingw";
#elif defined(__DJGPP__)
	return "djgpp";
#elif defined(__EMX__)
	return "os2";
#elif defined(USE_EBCDIC)
	return "os390";
#else
	return "posix";
#endif
}

/* set_current_namespace --- set current_namespace and handle memory management */

void
set_current_namespace(const char *new_namespace)
{
	if (current_namespace != awk_namespace)
		efree((void *) current_namespace);

	current_namespace = new_namespace;
}