/* $OpenBSD: unvis.c,v 1.14 2010/08/24 23:49:06 djm 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 #include #include /* * 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 = 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); } } /* * 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); }