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Diffstat (limited to 'lib/libc/gen/unvis.c')
| -rw-r--r-- | lib/libc/gen/unvis.c | 286 |
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); +} + |