c_ksh.c

一个开放源代码的 AT&T 的 Korn Shell 的复制品, 支持大多数 ksh89 的特性。

		ap = tenter(t, alias, h);
		ap->type = tflag ? CTALIAS : CALIAS;
		/* Are we setting the value or just some flags? */
		if ((val && !tflag) || (!val && tflag && !Uflag)) {
			if (ap->flag&ALLOC) {
				ap->flag &= ~(ALLOC|ISSET);
				afree((void*)ap->val.s, APERM);
			}
			/* ignore values for -t (at&t ksh does this) */
			newval = tflag ? search(alias, path, X_OK, (int *) 0)
					: val;
			if (newval) {
				ap->val.s = str_save(newval, APERM);
				ap->flag |= ALLOC|ISSET;
			} else
				ap->flag &= ~ISSET;
		}
		ap->flag |= DEFINED;
		if (prefix == '+')
			ap->flag &= ~xflag;
		else
			ap->flag |= xflag;
		if (val)
			afree(alias, ATEMP);
	}

	return rv;
}

int
c_unalias(wp)
	char **wp;
{
	register struct table *t = &aliases;
	register struct tbl *ap;
	int rv = 0, all = 0;
	int optc;

	while ((optc = ksh_getopt(wp, &builtin_opt, "adt")) != EOF)
		switch (optc) {
		  case 'a':
			all = 1;
			break;
		  case 'd':
			t = &homedirs;
			break;
		  case 't':
			t = &taliases;
			break;
		  case '?':
			return 1;
		}
	wp += builtin_opt.optind;

	for (; *wp != NULL; wp++) {
		ap = tsearch(t, *wp, hash(*wp));
		if (ap == NULL) {
			rv = 1;	/* POSIX */
			continue;
		}
		if (ap->flag&ALLOC) {
			ap->flag &= ~(ALLOC|ISSET);
			afree((void*)ap->val.s, APERM);
		}
		ap->flag &= ~(DEFINED|ISSET|EXPORT);
	}

	if (all) {
		struct tstate ts;

		for (twalk(&ts, t); (ap = tnext(&ts)); ) {
			if (ap->flag&ALLOC) {
				ap->flag &= ~(ALLOC|ISSET);
				afree((void*)ap->val.s, APERM);
			}
			ap->flag &= ~(DEFINED|ISSET|EXPORT);
		}
	}

	return rv;
}

#ifdef KSH
int
c_let(wp)
	char **wp;
{
	int rv = 1;
	long val;

	if (wp[1] == (char *) 0) /* at&t ksh does this */
		bi_errorf("no arguments");
	else
		for (wp++; *wp; wp++)
			if (!evaluate(*wp, &val, KSH_RETURN_ERROR)) {
				rv = 2;	/* distinguish error from zero result */
				break;
			} else
				rv = val == 0;
	return rv;
}
#endif /* KSH */

int
c_jobs(wp)
	char **wp;
{
	int optc;
	int flag = 0;
	int nflag = 0;
	int rv = 0;

	while ((optc = ksh_getopt(wp, &builtin_opt, "lpnz")) != EOF)
		switch (optc) {
		  case 'l':
			flag = 1;
			break;
		  case 'p':
			flag = 2;
			break;
		  case 'n':
			nflag = 1;
			break;
		  case 'z':	/* debugging: print zombies */
			nflag = -1;
			break;
		  case '?':
			return 1;
		}
	wp += builtin_opt.optind;
	if (!*wp)
		if (j_jobs((char *) 0, flag, nflag))
			rv = 1;
	else
		for (; *wp; wp++)
			if (j_jobs(*wp, flag, nflag))
				rv = 1;
	return rv;
}

#ifdef JOBS
int
c_fgbg(wp)
	char **wp;
{
	int bg = strcmp(*wp, "bg") == 0;
	int UNINITIALIZED(rv);

	if (!Flag(FMONITOR)) {
		bi_errorf("job control not enabled");
		return 1;
	}
	if (ksh_getopt(wp, &builtin_opt, null) == '?')
		return 1;
	wp += builtin_opt.optind;
	if (*wp)
		for (; *wp; wp++)
			rv = j_resume(*wp, bg);
	else
		rv = j_resume("%%", bg);
	/* POSIX says fg shall return 0 (unless an error occurs).
	 * at&t ksh returns the exit value of the job...
	 */
	return (bg || Flag(FPOSIX)) ? 0 : rv;
}
#endif

struct kill_info {
	int num_width;
	int name_width;
};
static char *kill_fmt_entry ARGS((void *arg, int i, char *buf, int buflen));

/* format a single kill item */
static char *
kill_fmt_entry(arg, i, buf, buflen)
	void *arg;
	int i;
	char *buf;
	int buflen;
{
	struct kill_info *ki = (struct kill_info *) arg;

	i++;
	if (sigtraps[i].name)
		shf_snprintf(buf, buflen, "%*d %*s %s",
			ki->num_width, i,
			ki->name_width, sigtraps[i].name,
			sigtraps[i].mess);
	else
		shf_snprintf(buf, buflen, "%*d %*d %s",
			ki->num_width, i,
			ki->name_width, sigtraps[i].signal,
			sigtraps[i].mess);
	return buf;
}


int
c_kill(wp)
	char **wp;
{
	Trap *t = (Trap *) 0;
	char *p;
	int lflag = 0;
	int i, n, rv, sig;

	/* assume old style options if -digits or -UPPERCASE */
	if ((p = wp[1]) && *p == '-' && (digit(p[1]) || isupper(p[1]))) {
		if (!(t = gettrap(p + 1, TRUE))) {
			bi_errorf("bad signal `%s'", p + 1);
			return 1;
		}
		i = (wp[2] && strcmp(wp[2], "--") == 0) ? 3 : 2;
	} else {
		int optc;

		while ((optc = ksh_getopt(wp, &builtin_opt, "ls:")) != EOF)
			switch (optc) {
			  case 'l':
				lflag = 1;
				break;
			  case 's':
				if (!(t = gettrap(builtin_opt.optarg, TRUE))) {
					bi_errorf("bad signal `%s'",
						builtin_opt.optarg);
					return 1;
				}
			  case '?':
				return 1;
			}
		i = builtin_opt.optind;
	}
	if ((lflag && t) || (!wp[i] && !lflag)) {
		shf_fprintf(shl_out,
"Usage: kill [ -s signame | -signum | -signame ] {pid|job}...\n\
       kill -l [exit_status]\n"
			);
		bi_errorf(null);
		return 1;
	}

	if (lflag) {
		if (wp[i]) {
			for (; wp[i]; i++) {
				if (!bi_getn(wp[i], &n))
					return 1;
				if (n > 128 && n < 128 + SIGNALS)
					n -= 128;
				if (n > 0 && n < SIGNALS && sigtraps[n].name)
					shprintf("%s\n", sigtraps[n].name);
				else
					shprintf("%d\n", n);
			}
		} else if (Flag(FPOSIX)) {
			p = null;
			for (i = 1; i < SIGNALS; i++, p = space)
				if (sigtraps[i].name)
					shprintf("%s%s", p, sigtraps[i].name);
			shprintf(newline);
		} else {
			int w, i;
			int mess_width;
			struct kill_info ki;

			for (i = SIGNALS, ki.num_width = 1; i >= 10; i /= 10)
				ki.num_width++;
			ki.name_width = mess_width = 0;
			for (i = 0; i < SIGNALS; i++) {
				w = sigtraps[i].name ? strlen(sigtraps[i].name)
						     : ki.num_width;
				if (w > ki.name_width)
					ki.name_width = w;
				w = strlen(sigtraps[i].mess);
				if (w > mess_width)
					mess_width = w;
			}

			print_columns(shl_stdout, SIGNALS - 1,
				kill_fmt_entry, (void *) &ki,
				ki.num_width + ki.name_width + mess_width + 3);
		}
		return 0;
	}
	rv = 0;
	sig = t ? t->signal : SIGTERM;
	for (; (p = wp[i]); i++) {
		if (*p == '%') {
			if (j_kill(p, sig))
				rv = 1;
		} else if (!getn(p, &n)) {
			bi_errorf("%s: arguments must be jobs or process ids",
				p);
			rv = 1;
		} else {
			/* use killpg if < -1 since -1 does special things for
			 * some non-killpg-endowed kills
			 */
			if ((n < -1 ? killpg(-n, sig) : kill(n, sig)) < 0) {
				bi_errorf("%s: %s", p, strerror(errno));
				rv = 1;
			}
		}
	}
	return rv;
}

void
getopts_reset(val)
	int val;
{
	if (val >= 1) {
		ksh_getopt_reset(&user_opt,
			GF_NONAME | (Flag(FPOSIX) ? 0 : GF_PLUSOPT));
		user_opt.optind = user_opt.uoptind = val;
	}
}

int
c_getopts(wp)
	char **wp;
{
	int	argc;
	const char *options;
	const char *var;
	int	optc;
	int	ret;
	char	buf[3];
	struct tbl *vq, *voptarg;

	if (ksh_getopt(wp, &builtin_opt, null) == '?')
		return 1;
	wp += builtin_opt.optind;

	options = *wp++;
	if (!options) {
		bi_errorf("missing options argument");
		return 1;
	}

	var = *wp++;
	if (!var) {
		bi_errorf("missing name argument");
		return 1;
	}
	if (!*var || *skip_varname(var, TRUE)) {
		bi_errorf("%s: is not an identifier", var);
		return 1;
	}

	if (e->loc->next == (struct block *) 0) {
		internal_errorf(0, "c_getopts: no argv");
		return 1;
	}
	/* Which arguments are we parsing... */
	if (*wp == (char *) 0)
		wp = e->loc->next->argv;
	else
		*--wp = e->loc->next->argv[0];

	/* Check that our saved state won't cause a core dump... */
	for (argc = 0; wp[argc]; argc++)
		;
	if (user_opt.optind > argc
	    || (user_opt.p != 0
		&& user_opt.p > strlen(wp[user_opt.optind - 1])))
	{
	      bi_errorf("arguments changed since last call");
	      return 1;
	}

	user_opt.optarg = (char *) 0;
	optc = ksh_getopt(wp, &user_opt, options);

	if (optc >= 0 && optc != '?' && (user_opt.info & GI_PLUS)) {
		buf[0] = '+';
		buf[1] = optc;
		buf[2] = '\0';
	} else {
		/* POSIX says var is set to ? at end-of-options, at&t ksh
		 * sets it to null - we go with POSIX...
		 */
		buf[0] = optc < 0 ? '?' : optc;
		buf[1] = '\0';
	}

	/* at&t ksh does not change OPTIND if it was an unknown option.
	 * Scripts counting on this are prone to break... (ie, don't count
	 * on this staying).
	 */
	if (optc != '?') {
		user_opt.uoptind = user_opt.optind;
	}

	voptarg = global("OPTARG");
	voptarg->flag &= ~RDONLY;	/* at&t ksh clears ro and int */
	/* Paranoia: ensure no bizarre results. */
	if (voptarg->flag & INTEGER)
	    typeset("OPTARG", 0, INTEGER, 0, 0);
	if (user_opt.optarg == (char *) 0)
		unset(voptarg, 0);
	else
		/* This can't fail (have cleared readonly/integer) */
		setstr(voptarg, user_opt.optarg, KSH_RETURN_ERROR);

	ret = 0;

	vq = global(var);
	/* Error message already printed (integer, readonly) */
	if (!setstr(vq, buf, KSH_RETURN_ERROR))
	    ret = 1;
	if (Flag(FEXPORT))
		typeset(var, EXPORT, 0, 0, 0);

	return optc < 0 ? 1 : ret;
}

#ifdef EMACS
int
c_bind(wp)
	char **wp;
{
	int rv = 0, macro = 0, list = 0;
	register char *cp;
	int optc;

	while ((optc = ksh_getopt(wp, &builtin_opt, "lm")) != EOF)
		switch (optc) {
		  case 'l':
			list = 1;
			break;
		  case 'm':
			macro = 1;
			break;
		  case '?':
			return 1;
		}
	wp += builtin_opt.optind;

	if (*wp == NULL)	/* list all */
		rv = x_bind((char*)NULL, (char*)NULL, 0, list);

	for (; *wp != NULL; wp++) {
		cp = strchr(*wp, '=');
		if (cp != NULL)
			*cp++ = '\0';
		if (x_bind(*wp, cp, macro, 0))
			rv = 1;
	}

	return rv;
}
#endif

/* A leading = means assignments before command are kept;
 * a leading * means a POSIX special builtin;
 * a leading + means a POSIX regular builtin
 * (* and + should not be combined).
 */
const struct builtin kshbuiltins [] = {
	{"+alias", c_alias},	/* no =: at&t manual wrong */
	{"+cd", c_cd},
	{"+command", c_command},
	{"echo", c_print},
 	{"*=export", c_typeset},
#ifdef HISTORY
	{"+fc", c_fc},
#endif /* HISTORY */
	{"+getopts", c_getopts},
	{"+jobs", c_jobs},
	{"+kill", c_kill},
#ifdef KSH
	{"let", c_let},
#endif /* KSH */
	{"print", c_print},
	{"pwd", c_pwd},
 	{"*=readonly", c_typeset},
	{"=typeset", c_typeset},
	{"+unalias", c_unalias},
	{"whence", c_whence},
#ifdef JOBS
	{"+bg", c_fgbg},
	{"+fg", c_fgbg},
#endif
#ifdef EMACS
	{"bind", c_bind},
#endif
	{NULL, NULL}
};