main.c

早期freebsd实现

GNU General Public License for more details.\n\
\n";
	static char blurb_part3[] =
"You should have received a copy of the GNU General Public License\n\
along with this program; if not, write to the Free Software\n\
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.\n";

	version();
	fputs(blurb_part1, stderr);
	fputs(blurb_part2, stderr);
	fputs(blurb_part3, stderr);
	fflush(stderr);
}

static void
cmdline_fs(str)
char *str;
{
	register NODE **tmp;
	int len = strlen(str);

	tmp = get_lhs(FS_node, (Func_ptr *) 0);
	unref(*tmp);
	/*
	 * Only if in full compatibility mode check for the stupid special
	 * case so -F\t works as documented in awk even though the shell
	 * hands us -Ft.  Bleah!
	 *
	 * Thankfully, Posix didn't propogate this "feature".
	 */
	if (str[0] == 't' && str[1] == '\0') {
		if (do_lint)
			warning("-Ft does not set FS to tab in POSIX awk");
		if (do_unix && ! do_posix)
			str[0] = '\t';
	}
	*tmp = make_str_node(str, len, SCAN);	/* do process escapes */
	set_FS();
}

static void
init_args(argc0, argc, argv0, argv)
int argc0, argc;
char *argv0;
char **argv;
{
	int i, j;
	NODE **aptr;

	ARGV_node = install("ARGV", node(Nnull_string, Node_var, (NODE *)NULL));
	aptr = assoc_lookup(ARGV_node, tmp_number(0.0));
	*aptr = make_string(argv0, strlen(argv0));
	(*aptr)->flags |= MAYBE_NUM;
	for (i = argc0, j = 1; i < argc; i++) {
		aptr = assoc_lookup(ARGV_node, tmp_number((AWKNUM) j));
		*aptr = make_string(argv[i], strlen(argv[i]));
		(*aptr)->flags |= MAYBE_NUM;
		j++;
	}
	ARGC_node = install("ARGC",
			node(make_number((AWKNUM) j), Node_var, (NODE *) NULL));
}

/*
 * Set all the special variables to their initial values.
 */
struct varinit {
	NODE **spec;
	char *name;
	NODETYPE type;
	char *strval;
	AWKNUM numval;
	Func_ptr assign;
};
static struct varinit varinit[] = {
{&NF_node,	"NF",		Node_NF,		0,	-1, set_NF },
{&FIELDWIDTHS_node, "FIELDWIDTHS", Node_FIELDWIDTHS,	"",	0,  0 },
{&NR_node,	"NR",		Node_NR,		0,	0,  set_NR },
{&FNR_node,	"FNR",		Node_FNR,		0,	0,  set_FNR },
{&FS_node,	"FS",		Node_FS,		" ",	0,  0 },
{&RS_node,	"RS",		Node_RS,		"\n",	0,  set_RS },
{&IGNORECASE_node, "IGNORECASE", Node_IGNORECASE,	0,	0,  set_IGNORECASE },
{&FILENAME_node, "FILENAME",	Node_var,		"-",	0,  0 },
{&OFS_node,	"OFS",		Node_OFS,		" ",	0,  set_OFS },
{&ORS_node,	"ORS",		Node_ORS,		"\n",	0,  set_ORS },
{&OFMT_node,	"OFMT",		Node_OFMT,		"%.6g",	0,  set_OFMT },
{&CONVFMT_node,	"CONVFMT",	Node_CONVFMT,		"%.6g",	0,  set_CONVFMT },
{&RLENGTH_node, "RLENGTH",	Node_var,		0,	0,  0 },
{&RSTART_node,	"RSTART",	Node_var,		0,	0,  0 },
{&SUBSEP_node,	"SUBSEP",	Node_var,		"\034",	0,  0 },
{&ARGIND_node,	"ARGIND",	Node_var,		0,	0,  0 },
{&ERRNO_node,	"ERRNO",	Node_var,		0,	0,  0 },
{0,		0,		Node_illegal,		0,	0,  0 },
};

static void
init_vars()
{
	register struct varinit *vp;

	for (vp = varinit; vp->name; vp++) {
		*(vp->spec) = install(vp->name,
		  node(vp->strval == 0 ? make_number(vp->numval)
				: make_string(vp->strval, strlen(vp->strval)),
		       vp->type, (NODE *) NULL));
		if (vp->assign)
			(*(vp->assign))();
	}
}

void
load_environ()
{
#if !defined(MSDOS) && !(defined(VMS) && defined(__DECC))
	extern char **environ;
#endif
	register char *var, *val;
	NODE **aptr;
	register int i;

	ENVIRON_node = install("ENVIRON", 
			node(Nnull_string, Node_var, (NODE *) NULL));
	for (i = 0; environ[i]; i++) {
		static char nullstr[] = "";

		var = environ[i];
		val = strchr(var, '=');
		if (val)
			*val++ = '\0';
		else
			val = nullstr;
		aptr = assoc_lookup(ENVIRON_node, tmp_string(var, strlen (var)));
		*aptr = make_string(val, strlen (val));
		(*aptr)->flags |= MAYBE_NUM;

		/* restore '=' so that system() gets a valid environment */
		if (val != nullstr)
			*--val = '=';
	}
}

/* Process a command-line assignment */
char *
arg_assign(arg)
char *arg;
{
	char *cp;
	Func_ptr after_assign = NULL;
	NODE *var;
	NODE *it;
	NODE **lhs;

	cp = strchr(arg, '=');
	if (cp != NULL) {
		*cp++ = '\0';
		/*
		 * Recent versions of nawk expand escapes inside assignments.
		 * This makes sense, so we do it too.
		 */
		it = make_str_node(cp, strlen(cp), SCAN);
		it->flags |= MAYBE_NUM;
		var = variable(arg, 0);
		lhs = get_lhs(var, &after_assign);
		unref(*lhs);
		*lhs = it;
		if (after_assign)
			(*after_assign)();
		*--cp = '=';	/* restore original text of ARGV */
	}
	return cp;
}

static void
pre_assign(v)
char *v;
{
	if (!arg_assign(v)) {
		fprintf (stderr,
			"%s: '%s' argument to -v not in 'var=value' form\n",
				myname, v);
		usage(1);
	}
}

SIGTYPE
catchsig(sig, code)
int sig, code;
{
#ifdef lint
	code = 0; sig = code; code = sig;
#endif
	if (sig == SIGFPE) {
		fatal("floating point exception");
	} else if (sig == SIGSEGV
#ifdef SIGBUS
	        || sig == SIGBUS
#endif
	) {
		msg("fatal error: internal error");
		/* fatal won't abort() if not compiled for debugging */
		abort();
	} else
		cant_happen();
	/* NOTREACHED */
}

/* gawk_option --- do gawk specific things */

static void
gawk_option(optstr)
char *optstr;
{
	char *cp;

	for (cp = optstr; *cp; cp++) {
		switch (*cp) {
		case ' ':
		case '\t':
		case ',':
			break;
		case 'v':
		case 'V':
			/* print version */
			if (strncasecmp(cp, "version", 7) != 0)
				goto unknown;
			else
				cp += 6;
			version();
			break;
		case 'c':
		case 'C':
			if (strncasecmp(cp, "copyright", 9) == 0) {
				cp += 8;
				copyleft();
			} else if (strncasecmp(cp, "copyleft", 8) == 0) {
				cp += 7;
				copyleft();
			} else if (strncasecmp(cp, "compat", 6) == 0) {
				cp += 5;
				do_unix = 1;
			} else
				goto unknown;
			break;
		case 'n':
		case 'N':
			/*
			 * Undocumented feature,
			 * inspired by nostalgia, and a T-shirt
			 */
			if (strncasecmp(cp, "nostalgia", 9) != 0)
				goto unknown;
			nostalgia();
			break;
		case 'p':
		case 'P':
#ifdef DEBUG
			if (strncasecmp(cp, "parsedebug", 10) == 0) {
				cp += 9;
				yydebug = 2;
				break;
			}
#endif
			if (strncasecmp(cp, "posix", 5) != 0)
				goto unknown;
			cp += 4;
			do_posix = do_unix = 1;
			break;
		case 'l':
		case 'L':
			if (strncasecmp(cp, "lint", 4) != 0)
				goto unknown;
			cp += 3;
			do_lint = 1;
			break;
		case 'H':
		case 'h':
			if (strncasecmp(cp, "help", 4) != 0)
				goto unknown;
			cp += 3;
			usage(0);
			break;
		case 'U':
		case 'u':
			if (strncasecmp(cp, "usage", 5) != 0)
				goto unknown;
			cp += 4;
			usage(0);
			break;
		case 's':
		case 'S':
			if (strncasecmp(cp, "source=", 7) != 0)
				goto unknown;
			cp += 7;
			if (strlen(cp) == 0)
				warning("empty argument to -Wsource ignored");
			else {
				srcfiles[++numfiles].stype = CMDLINE;
				srcfiles[numfiles].val = cp;
				return;
			}
			break;
		default:
		unknown:
			fprintf(stderr, "'%c' -- unknown option, ignored\n",
				*cp);
			break;
		}
	}
}

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

static void
nostalgia()
{
	fprintf(stderr, "awk: bailing out near line 1\n");
	abort();
}

/* version --- print version message */

static void
version()
{
	fprintf(stderr, "%s, patchlevel %d\n", version_string, PATCHLEVEL);
}

/* static */
char *
gawk_name(filespec)
char *filespec;
{
        char *p;
    
#ifdef VMS	/* "device:[root.][directory.subdir]GAWK.EXE;n" -> "GAWK" */
        char *q;

        p = strrchr(filespec, ']');  /* directory punctuation */
        q = strrchr(filespec, '>');  /* alternate <international> punct */

        if (p == NULL || q > p) p = q;
	p = strdup(p == NULL ? filespec : (p + 1));
	if ((q = strrchr(p, '.')) != NULL)  *q = '\0';  /* strip .typ;vers */

	return p;
#endif /*VMS*/

#if defined(MSDOS) || defined(atarist)
        char *q;

        p = filespec;
	
        if (q = strrchr(p, '\\'))
            p = q + 1;
        if (q = strchr(p, '.'))
    	    *q = '\0';
        strlwr(p);

        return (p == NULL ? filespec : p);
#endif /* MSDOS || atarist */

	/* "path/name" -> "name" */
	p = strrchr(filespec, '/');
	return (p == NULL ? filespec : p + 1);
}