Add in tr and dirname

 -Erik

2 files changed, 724 insertions, 0 deletions

diff --git a/coreutils/dirname.c b/coreutils/dirname.c
new file mode 100644
index 0000000..77cb664
--- /dev/null
+++ b/coreutils/dirname.c
@@ -0,0 +1,146 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * This is temporary -- needs to be rewritten to be tighter */
+/*
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if 0
+#ifndef lint
+static char copyright[] = "@(#) Copyright (c) 1991, 1993, 1994\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif							/* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)dirname.c	8.4 (Berkeley) 5/4/95";
+#endif							/* not lint */
+#endif							/* #if 0 */
+
+#include "internal.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+void dirname_usage()
+{
+
+	(void) fprintf(stderr, "usage: dirname path\n");
+	exit(1);
+}
+
+extern int dirname_main(argc, argv)
+int argc;
+char **argv;
+{
+	char *p;
+	int ch;
+
+	while ((ch = getopt(argc, argv, "")) != -1)
+		switch (ch) {
+		case '?':
+		default:
+			dirname_usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+	if (argc != 1)
+		dirname_usage();
+
+	/*
+	 * (1) If string is //, skip steps (2) through (5).
+	 * (2) If string consists entirely of slash characters, string
+	 *     shall be set to a single slash character.  In this case,
+	 *     skip steps (3) through (8).
+	 */
+	for (p = *argv;; ++p) {
+		if (!*p) {
+			if (p > *argv)
+				(void) printf("/\n");
+			else
+				(void) printf(".\n");
+			exit(0);
+		}
+		if (*p != '/')
+			break;
+	}
+
+	/*
+	 * (3) If there are any trailing slash characters in string, they
+	 *     shall be removed.
+	 */
+	for (; *p; ++p);
+	while (*--p == '/')
+		continue;
+	*++p = '\0';
+
+	/*
+	 * (4) If there are no slash characters remaining in string,
+	 *     string shall be set to a single period character.  In this
+	 *     case skip steps (5) through (8).
+	 *
+	 * (5) If there are any trailing nonslash characters in string,
+	 *     they shall be removed.
+	 */
+	while (--p >= *argv)
+		if (*p == '/')
+			break;
+	++p;
+	if (p == *argv) {
+		(void) printf(".\n");
+		exit(0);
+	}
+
+	/*
+	 * (6) If the remaining string is //, it is implementation defined
+	 *     whether steps (7) and (8) are skipped or processed.
+	 *
+	 * This case has already been handled, as part of steps (1) and (2).
+	 */
+
+	/*
+	 * (7) If there are any trailing slash characters in string, they
+	 *     shall be removed.
+	 */
+	while (--p >= *argv)
+		if (*p != '/')
+			break;
+	++p;
+
+	/*
+	 * (8) If the remaining string is empty, string shall be set to
+	 *     a single slash character.
+	 */
+	*p = '\0';
+	(void) printf("%s\n", p == *argv ? "/" : *argv);
+	exit(0);
+}
diff --git a/coreutils/tr.c b/coreutils/tr.c
new file mode 100644
index 0000000..8ac09e6
--- /dev/null
+++ b/coreutils/tr.c
@@ -0,0 +1,578 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (c) 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if 0
+#ifndef lint
+static const char copyright[] = "@(#) Copyright (c) 1988, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif							/* not lint */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)tr.c	8.2 (Berkeley) 5/4/95";
+#endif
+static const char rcsid[] =
+
+	"$Id: tr.c,v 1.1 2000/03/05 08:07:00 erik Exp $";
+#endif							/* not lint */
+#endif							/* #if 0 */
+
+#include "internal.h"
+#include <locale.h>
+#include <sys/types.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <stddef.h>
+
+typedef struct {
+	enum { STRING1, STRING2 } which;
+	enum { EOS, INFINITE, NORMAL, RANGE, SEQUENCE, SET } state;
+	int cnt;					/* character count */
+	int lastch;					/* last character */
+	int equiv[2];				/* equivalence set */
+	int *set;					/* set of characters */
+	char *str;					/* user's string */
+} STR;
+
+#include <limits.h>
+#define	NCHARS	(UCHAR_MAX + 1)	/* Number of possible characters. */
+#define	OOBCH	(UCHAR_MAX + 1)	/* Out of band character value. */
+
+static int next __P((STR *));
+
+static int string1[NCHARS] = {
+	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,	/* ASCII */
+	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
+	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
+	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
+	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
+	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
+	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+}, string2[NCHARS];
+
+STR s1 = { STRING1, NORMAL, 0, OOBCH, {0, OOBCH}, NULL, NULL };
+STR s2 = { STRING2, NORMAL, 0, OOBCH, {0, OOBCH}, NULL, NULL };
+
+static void setup(string, arg, str, cflag)
+int *string;
+char *arg;
+STR *str;
+int cflag;
+{
+	register int cnt, *p;
+
+	str->str = arg;
+	bzero(string, NCHARS * sizeof(int));
+
+	while (next(str))
+		string[str->lastch] = 1;
+	if (cflag)
+		for (p = string, cnt = NCHARS; cnt--; ++p)
+			*p = !*p;
+}
+
+static void tr_usage()
+{
+	(void) fprintf(stderr, "%s\n%s\n%s\n%s\n",
+				   "usage: tr [-csu] string1 string2",
+				   "       tr [-cu] -d string1",
+				   "       tr [-cu] -s string1",
+				   "       tr [-cu] -ds string1 string2");
+	exit(1);
+}
+
+
+extern int tr_main(argc, argv)
+int argc;
+char **argv;
+{
+	register int ch, cnt, lastch, *p;
+	int cflag, dflag, sflag, isstring2;
+
+	(void) setlocale(LC_CTYPE, "");
+
+	cflag = dflag = sflag = 0;
+	while ((ch = getopt(argc, argv, "cdsu")) != -1)
+		switch ((char) ch) {
+		case 'c':
+			cflag = 1;
+			break;
+		case 'd':
+			dflag = 1;
+			break;
+		case 's':
+			sflag = 1;
+			break;
+		case 'u':
+			setbuf(stdout, (char *) NULL);
+			break;
+		case '?':
+		default:
+			tr_usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+	switch (argc) {
+	case 0:
+	default:
+		tr_usage();
+		/* NOTREACHED */
+	case 1:
+		isstring2 = 0;
+		break;
+	case 2:
+		isstring2 = 1;
+		break;
+	}
+
+	/*
+	 * tr -ds [-c] string1 string2
+	 * Delete all characters (or complemented characters) in string1.
+	 * Squeeze all characters in string2.
+	 */
+	if (dflag && sflag) {
+		if (!isstring2)
+			tr_usage();
+
+		setup(string1, argv[0], &s1, cflag);
+		setup(string2, argv[1], &s2, 0);
+
+		for (lastch = OOBCH; (ch = getchar()) != EOF;)
+			if (!string1[ch] && (!string2[ch] || lastch != ch)) {
+				lastch = ch;
+				(void) putchar(ch);
+			}
+		exit(0);
+	}
+
+	/*
+	 * tr -d [-c] string1
+	 * Delete all characters (or complemented characters) in string1.
+	 */
+	if (dflag) {
+		if (isstring2)
+			tr_usage();
+
+		setup(string1, argv[0], &s1, cflag);
+
+		while ((ch = getchar()) != EOF)
+			if (!string1[ch])
+				(void) putchar(ch);
+		exit(0);
+	}
+
+	/*
+	 * tr -s [-c] string1
+	 * Squeeze all characters (or complemented characters) in string1.
+	 */
+	if (sflag && !isstring2) {
+		setup(string1, argv[0], &s1, cflag);
+
+		for (lastch = OOBCH; (ch = getchar()) != EOF;)
+			if (!string1[ch] || lastch != ch) {
+				lastch = ch;
+				(void) putchar(ch);
+			}
+		exit(0);
+	}
+
+	/*
+	 * tr [-cs] string1 string2
+	 * Replace all characters (or complemented characters) in string1 with
+	 * the character in the same position in string2.  If the -s option is
+	 * specified, squeeze all the characters in string2.
+	 */
+	if (!isstring2)
+		tr_usage();
+
+	s1.str = argv[0];
+	s2.str = argv[1];
+
+	if (cflag)
+		for (cnt = NCHARS, p = string1; cnt--;)
+			*p++ = OOBCH;
+
+	if (!next(&s2))
+		errx(1, "empty string2");
+
+	/* If string2 runs out of characters, use the last one specified. */
+	if (sflag)
+		while (next(&s1)) {
+			string1[s1.lastch] = ch = s2.lastch;
+			string2[ch] = 1;
+			(void) next(&s2);
+	} else
+		while (next(&s1)) {
+			string1[s1.lastch] = ch = s2.lastch;
+			(void) next(&s2);
+		}
+
+	if (cflag)
+		for (cnt = 0, p = string1; cnt < NCHARS; ++p, ++cnt)
+			*p = *p == OOBCH ? ch : cnt;
+
+	if (sflag)
+		for (lastch = OOBCH; (ch = getchar()) != EOF;) {
+			ch = string1[ch];
+			if (!string2[ch] || lastch != ch) {
+				lastch = ch;
+				(void) putchar(ch);
+			}
+	} else
+		while ((ch = getchar()) != EOF)
+			(void) putchar(string1[ch]);
+	exit(0);
+}
+
+static int backslash __P((STR *));
+static int bracket __P((STR *));
+static int c_class __P((const void *, const void *));
+static void genclass __P((STR *));
+static void genequiv __P((STR *));
+static int genrange __P((STR *));
+static void genseq __P((STR *));
+
+static int next(s)
+register STR *s;
+{
+	register int ch;
+
+	switch (s->state) {
+	case EOS:
+		return (0);
+	case INFINITE:
+		return (1);
+	case NORMAL:
+		switch (ch = (u_char) * s->str) {
+		case '\0':
+			s->state = EOS;
+			return (0);
+		case '\\':
+			s->lastch = backslash(s);
+			break;
+		case '[':
+			if (bracket(s))
+				return (next(s));
+			/* FALLTHROUGH */
+		default:
+			++s->str;
+			s->lastch = ch;
+			break;
+		}
+
+		/* We can start a range at any time. */
+		if (s->str[0] == '-' && genrange(s))
+			return (next(s));
+		return (1);
+	case RANGE:
+		if (s->cnt-- == 0) {
+			s->state = NORMAL;
+			return (next(s));
+		}
+		++s->lastch;
+		return (1);
+	case SEQUENCE:
+		if (s->cnt-- == 0) {
+			s->state = NORMAL;
+			return (next(s));
+		}
+		return (1);
+	case SET:
+		if ((s->lastch = s->set[s->cnt++]) == OOBCH) {
+			s->state = NORMAL;
+			return (next(s));
+		}
+		return (1);
+	}
+	/* NOTREACHED */
+	return (0);
+}
+
+static int bracket(s)
+register STR *s;
+{
+	register char *p;
+
+	switch (s->str[1]) {
+	case ':':					/* "[:class:]" */
+		if ((p = strstr(s->str + 2, ":]")) == NULL)
+			return (0);
+		*p = '\0';
+		s->str += 2;
+		genclass(s);
+		s->str = p + 2;
+		return (1);
+	case '=':					/* "[=equiv=]" */
+		if ((p = strstr(s->str + 2, "=]")) == NULL)
+			return (0);
+		s->str += 2;
+		genequiv(s);
+		return (1);
+	default:					/* "[\###*n]" or "[#*n]" */
+		if ((p = strpbrk(s->str + 2, "*]")) == NULL)
+			return (0);
+		if (p[0] != '*' || index(p, ']') == NULL)
+			return (0);
+		s->str += 1;
+		genseq(s);
+		return (1);
+	}
+	/* NOTREACHED */
+}
+
+typedef struct {
+	char *name;
+	int (*func) __P((int));
+	int *set;
+} CLASS;
+
+static CLASS classes[] = {
+#undef isalnum
+	{"alnum", isalnum,},
+#undef isalpha
+	{"alpha", isalpha,},
+/*#undef isblank
+	{ "blank",  isblank,  },*/
+#undef iscntrl
+	{"cntrl", iscntrl,},
+#undef isdigit
+	{"digit", isdigit,},
+#undef isgraph
+	{"graph", isgraph,},
+#undef islower
+	{"lower", islower,},
+#undef isprint
+	{"print", isprint,},
+#undef ispunct
+	{"punct", ispunct,},
+#undef isspace
+	{"space", isspace,},
+#undef isupper
+	{"upper", isupper,},
+#undef isxdigit
+	{"xdigit", isxdigit,},
+};
+
+static void genclass(s)
+STR *s;
+{
+	register int cnt, (*func) __P((int));
+	CLASS *cp, tmp;
+	int *p;
+
+	tmp.name = s->str;
+	if ((cp = (CLASS *) bsearch(&tmp, classes, sizeof(classes) /
+								sizeof(CLASS), sizeof(CLASS),
+								c_class)) == NULL) errx(1,
+														"unknown class %s",
+														s->str);
+
+	if ((cp->set = p = malloc((NCHARS + 1) * sizeof(int))) == NULL)
+		errx(1, "malloc");
+	bzero(p, (NCHARS + 1) * sizeof(int));
+
+	for (cnt = 0, func = cp->func; cnt < NCHARS; ++cnt)
+		if ((func) (cnt))
+			*p++ = cnt;
+	*p = OOBCH;
+
+	s->cnt = 0;
+	s->state = SET;
+	s->set = cp->set;
+}
+
+static int c_class(a, b)
+const void *a, *b;
+{
+	return (strcmp(((CLASS *) a)->name, ((CLASS *) b)->name));
+}
+
+/*
+ * English doesn't have any equivalence classes, so for now
+ * we just syntax check and grab the character.
+ */
+static void genequiv(s)
+STR *s;
+{
+	if (*s->str == '\\') {
+		s->equiv[0] = backslash(s);
+		if (*s->str != '=')
+			errx(1, "misplaced equivalence equals sign");
+	} else {
+		s->equiv[0] = s->str[0];
+		if (s->str[1] != '=')
+			errx(1, "misplaced equivalence equals sign");
+	}
+	s->str += 2;
+	s->cnt = 0;
+	s->state = SET;
+	s->set = s->equiv;
+}
+
+static int genrange(s)
+STR *s;
+{
+	int stopval;
+	char *savestart;
+
+	savestart = s->str;
+	stopval = *++s->str == '\\' ? backslash(s) : (u_char) * s->str++;
+	if (stopval < (u_char) s->lastch) {
+		s->str = savestart;
+		return (0);
+	}
+	s->cnt = stopval - s->lastch + 1;
+	s->state = RANGE;
+	--s->lastch;
+	return (1);
+}
+
+static void genseq(s)
+STR *s;
+{
+	char *ep;
+
+	if (s->which == STRING1)
+		errx(1, "sequences only valid in string2");
+
+	if (*s->str == '\\')
+		s->lastch = backslash(s);
+	else
+		s->lastch = *s->str++;
+	if (*s->str != '*')
+		errx(1, "misplaced sequence asterisk");
+
+	switch (*++s->str) {
+	case '\\':
+		s->cnt = backslash(s);
+		break;
+	case ']':
+		s->cnt = 0;
+		++s->str;
+		break;
+	default:
+		if (isdigit((u_char) * s->str)) {
+			s->cnt = strtol(s->str, &ep, 0);
+			if (*ep == ']') {
+				s->str = ep + 1;
+				break;
+			}
+		}
+		errx(1, "illegal sequence count");
+		/* NOTREACHED */
+	}
+
+	s->state = s->cnt ? SEQUENCE : INFINITE;
+}
+
+/*
+ * Translate \??? into a character.  Up to 3 octal digits, if no digits either
+ * an escape code or a literal character.
+ */
+static int backslash(s)
+register STR *s;
+{
+	register int ch, cnt, val;
+
+	for (cnt = val = 0;;) {
+		ch = (u_char) * ++s->str;
+		if (!isascii(ch) || !isdigit(ch))
+			break;
+		val = val * 8 + ch - '0';
+		if (++cnt == 3) {
+			++s->str;
+			break;
+		}
+	}
+	if (cnt)
+		return (val);
+	if (ch != '\0')
+		++s->str;
+	switch (ch) {
+	case 'a':					/* escape characters */
+		return ('\7');
+	case 'b':
+		return ('\b');
+	case 'f':
+		return ('\f');
+	case 'n':
+		return ('\n');
+	case 'r':
+		return ('\r');
+	case 't':
+		return ('\t');
+	case 'v':
+		return ('\13');
+	case '\0':					/*  \" -> \ */
+		s->state = EOS;
+		return ('\\');
+	default:					/* \x" -> x */
+		return (ch);
+	}
+}