/* $Id: vis.c 3956 2010-01-05 20:56:56Z zacheiss $ * vis functions - visually encode characters * Originally from OpenBSD */ /*- * 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. 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. */ #ifndef HAVE_STRVIS #include "vis.h" /* * vis - visually encode characters */ char * vis(dst, c, flag, nextc) register char *dst; int c, nextc; register int flag; { if (isvisible(c)) { *dst++ = c; if (c == '\\' && (flag & VIS_NOSLASH) == 0) *dst++ = '\\'; *dst = '\0'; return (dst); } if (flag & VIS_CSTYLE) { switch(c) { case '\n': *dst++ = '\\'; *dst++ = 'n'; goto done; case '\r': *dst++ = '\\'; *dst++ = 'r'; goto done; case '\b': *dst++ = '\\'; *dst++ = 'b'; goto done; #ifdef __STDC__ case '\a': #else case '\007': #endif *dst++ = '\\'; *dst++ = 'a'; goto done; case '\v': *dst++ = '\\'; *dst++ = 'v'; goto done; case '\t': *dst++ = '\\'; *dst++ = 't'; goto done; case '\f': *dst++ = '\\'; *dst++ = 'f'; goto done; case ' ': *dst++ = '\\'; *dst++ = 's'; goto done; case '\0': *dst++ = '\\'; *dst++ = '0'; if (isoctal(nextc)) { *dst++ = '0'; *dst++ = '0'; } goto done; } } if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) { *dst++ = '\\'; *dst++ = ((u_char)c >> 6 & 07) + '0'; *dst++ = ((u_char)c >> 3 & 07) + '0'; *dst++ = ((u_char)c & 07) + '0'; goto done; } if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\'; if (c & 0200) { c &= 0177; *dst++ = 'M'; } if (iscntrl(c)) { *dst++ = '^'; if (c == 0177) *dst++ = '?'; else *dst++ = c + '@'; } else { *dst++ = '-'; *dst++ = c; } done: *dst = '\0'; return (dst); } /* * strvis, strnvis, strvisx - visually encode characters from src into dst * * Dst must be 4 times the size of src to account for possible * expansion. The length of dst, not including the trailing NULL, * is returned. * * Strnvis will write no more than siz-1 bytes (and will NULL terminate). * The number of bytes needed to fully encode the string is returned. * * Strvisx encodes exactly len bytes from src into dst. * This is useful for encoding a block of data. */ int strvis(dst, src, flag) register char *dst; register const char *src; int flag; { register char c; char *start; for (start = dst; (c = *src);) dst = vis(dst, c, flag, *++src); *dst = '\0'; return (dst - start); } int strnvis(dst, src, siz, flag) register char *dst; register const char *src; size_t siz; int flag; { register char c; char *start, *end; for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { if (isvisible(c)) { *dst++ = c; if (c == '\\' && (flag & VIS_NOSLASH) == 0) { /* need space for the extra '\\' */ if (dst < end) *dst++ = '\\'; else { dst--; break; } } src++; } else { /* vis(3) requires up to 4 chars */ if (dst + 3 < end) dst = vis(dst, c, flag, *++src); else break; } } *dst = '\0'; if (dst >= end) { char tbuf[5]; /* adjust return value for truncation */ while ((c = *src)) dst += vis(tbuf, c, flag, *++src) - tbuf; } return (dst - start); } int strvisx(dst, src, len, flag) register char *dst; register const char *src; register size_t len; int flag; { register char c; char *start; for (start = dst; len > 1; len--) { c = *src; dst = vis(dst, c, flag, *++src); } if (len) dst = vis(dst, *src, flag, '\0'); *dst = '\0'; return (dst - start); } /* * unvis - decode characters previously encoded by vis */ int #ifdef __STDC__ unvis(char *cp, char c, int *astate, int flag) #else unvis(cp, c, astate, flag) char *cp; char c; int *astate, flag; #endif { 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(dst, src) register char *dst; register const char *src; { register 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: return (-1); } } if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) dst++; *dst = '\0'; return (dst - start); } #endif /* HAVE_STRVIS */