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-rw-r--r--lib/libc/gen/unvis.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/lib/libc/gen/unvis.c b/lib/libc/gen/unvis.c
new file mode 100644
index 0000000..05749aa
--- /dev/null
+++ b/lib/libc/gen/unvis.c
@@ -0,0 +1,286 @@
+/* $OpenBSD: unvis.c,v 1.17 2015/09/13 11:32:51 guenther Exp $ */
+/*-
+ * Copyright (c) 1989, 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. 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.
+ */
+
+#include <sys/types.h>
+#include <ctype.h>
+#include <vis.h>
+
+/*
+ * decode driven by state machine
+ */
+#define S_GROUND 0 /* haven't seen escape char */
+#define S_START 1 /* start decoding special sequence */
+#define S_META 2 /* metachar started (M) */
+#define S_META1 3 /* metachar more, regular char (-) */
+#define S_CTRL 4 /* control char started (^) */
+#define S_OCTAL2 5 /* octal digit 2 */
+#define S_OCTAL3 6 /* octal digit 3 */
+
+#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
+
+/*
+ * unvis - decode characters previously encoded by vis
+ */
+int
+unvis(char *cp, char c, int *astate, int flag)
+{
+
+ if (flag & UNVIS_END) {
+ if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ }
+ return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
+ }
+
+ switch (*astate) {
+
+ case S_GROUND:
+ *cp = 0;
+ if (c == '\\') {
+ *astate = S_START;
+ return (0);
+ }
+ *cp = c;
+ return (UNVIS_VALID);
+
+ case S_START:
+ switch(c) {
+ case '-':
+ *cp = 0;
+ *astate = S_GROUND;
+ return (0);
+ case '\\':
+ case '"':
+ *cp = c;
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case '0': case '1': case '2': case '3':
+ case '4': case '5': case '6': case '7':
+ *cp = (c - '0');
+ *astate = S_OCTAL2;
+ return (0);
+ case 'M':
+ *cp = (char) 0200;
+ *astate = S_META;
+ return (0);
+ case '^':
+ *astate = S_CTRL;
+ return (0);
+ case 'n':
+ *cp = '\n';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'r':
+ *cp = '\r';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'b':
+ *cp = '\b';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'a':
+ *cp = '\007';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'v':
+ *cp = '\v';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 't':
+ *cp = '\t';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'f':
+ *cp = '\f';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 's':
+ *cp = ' ';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case 'E':
+ *cp = '\033';
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+ case '\n':
+ /*
+ * hidden newline
+ */
+ *astate = S_GROUND;
+ return (UNVIS_NOCHAR);
+ case '$':
+ /*
+ * hidden marker
+ */
+ *astate = S_GROUND;
+ return (UNVIS_NOCHAR);
+ }
+ *astate = S_GROUND;
+ return (UNVIS_SYNBAD);
+
+ case S_META:
+ if (c == '-')
+ *astate = S_META1;
+ else if (c == '^')
+ *astate = S_CTRL;
+ else {
+ *astate = S_GROUND;
+ return (UNVIS_SYNBAD);
+ }
+ return (0);
+
+ case S_META1:
+ *astate = S_GROUND;
+ *cp |= c;
+ return (UNVIS_VALID);
+
+ case S_CTRL:
+ if (c == '?')
+ *cp |= 0177;
+ else
+ *cp |= c & 037;
+ *astate = S_GROUND;
+ return (UNVIS_VALID);
+
+ case S_OCTAL2: /* second possible octal digit */
+ if (isoctal(c)) {
+ /*
+ * yes - and maybe a third
+ */
+ *cp = (*cp << 3) + (c - '0');
+ *astate = S_OCTAL3;
+ return (0);
+ }
+ /*
+ * no - done with current sequence, push back passed char
+ */
+ *astate = S_GROUND;
+ return (UNVIS_VALIDPUSH);
+
+ case S_OCTAL3: /* third possible octal digit */
+ *astate = S_GROUND;
+ if (isoctal(c)) {
+ *cp = (*cp << 3) + (c - '0');
+ return (UNVIS_VALID);
+ }
+ /*
+ * we were done, push back passed char
+ */
+ return (UNVIS_VALIDPUSH);
+
+ default:
+ /*
+ * decoder in unknown state - (probably uninitialized)
+ */
+ *astate = S_GROUND;
+ return (UNVIS_SYNBAD);
+ }
+}
+DEF_WEAK(unvis);
+
+/*
+ * strunvis - decode src into dst
+ *
+ * Number of chars decoded into dst is returned, -1 on error.
+ * Dst is null terminated.
+ */
+
+int
+strunvis(char *dst, const char *src)
+{
+ char c;
+ char *start = dst;
+ int state = 0;
+
+ while ((c = *src++)) {
+ again:
+ switch (unvis(dst, c, &state, 0)) {
+ case UNVIS_VALID:
+ dst++;
+ break;
+ case UNVIS_VALIDPUSH:
+ dst++;
+ goto again;
+ case 0:
+ case UNVIS_NOCHAR:
+ break;
+ default:
+ *dst = '\0';
+ return (-1);
+ }
+ }
+ if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
+ dst++;
+ *dst = '\0';
+ return (dst - start);
+}
+
+ssize_t
+strnunvis(char *dst, const char *src, size_t sz)
+{
+ char c, p;
+ char *start = dst, *end = dst + sz - 1;
+ int state = 0;
+
+ if (sz > 0)
+ *end = '\0';
+ while ((c = *src++)) {
+ again:
+ switch (unvis(&p, c, &state, 0)) {
+ case UNVIS_VALID:
+ if (dst < end)
+ *dst = p;
+ dst++;
+ break;
+ case UNVIS_VALIDPUSH:
+ if (dst < end)
+ *dst = p;
+ dst++;
+ goto again;
+ case 0:
+ case UNVIS_NOCHAR:
+ break;
+ default:
+ if (dst <= end)
+ *dst = '\0';
+ return (-1);
+ }
+ }
+ if (unvis(&p, c, &state, UNVIS_END) == UNVIS_VALID) {
+ if (dst < end)
+ *dst = p;
+ dst++;
+ }
+ if (dst <= end)
+ *dst = '\0';
+ return (dst - start);
+}
+
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