| 1 | /*- |
| 2 | * Copyright (c) 1989 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * %sccs.include.redist.c% |
| 6 | */ |
| 7 | |
| 8 | #if defined(LIBC_SCCS) && !defined(lint) |
| 9 | static char sccsid[] = "@(#)vis.c 5.4 (Berkeley) %G%"; |
| 10 | #endif /* LIBC_SCCS and not lint */ |
| 11 | |
| 12 | #include <sys/types.h> |
| 13 | #include <ctype.h> |
| 14 | #include <vis.h> |
| 15 | |
| 16 | #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') |
| 17 | |
| 18 | /* |
| 19 | * vis - visually encode characters |
| 20 | */ |
| 21 | char * |
| 22 | #if __STDC__ |
| 23 | vis(register char *dst, register char c, register int flag, char nextc) |
| 24 | #else |
| 25 | vis(dst, c, flag, nextc) |
| 26 | register char *dst, c; |
| 27 | char nextc; |
| 28 | register int flag; |
| 29 | #endif |
| 30 | { |
| 31 | if (isascii(c) && isgraph(c) || |
| 32 | ((flag & VIS_SP) == 0 && c == ' ') || |
| 33 | ((flag & VIS_TAB) == 0 && c == '\t') || |
| 34 | ((flag & VIS_NL) == 0 && c == '\n') || |
| 35 | ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) { |
| 36 | *dst++ = c; |
| 37 | if (c == '\\' && (flag & VIS_NOSLASH) == 0) |
| 38 | *dst++ = '\\'; |
| 39 | *dst = '\0'; |
| 40 | return (dst); |
| 41 | } |
| 42 | |
| 43 | if (flag & VIS_CSTYLE) { |
| 44 | switch(c) { |
| 45 | case '\n': |
| 46 | *dst++ = '\\'; |
| 47 | *dst++ = 'n'; |
| 48 | goto done; |
| 49 | case '\r': |
| 50 | *dst++ = '\\'; |
| 51 | *dst++ = 'r'; |
| 52 | goto done; |
| 53 | case '\b': |
| 54 | *dst++ = '\\'; |
| 55 | *dst++ = 'b'; |
| 56 | goto done; |
| 57 | #if __STDC__ |
| 58 | case '\a': |
| 59 | #else |
| 60 | case '\007': |
| 61 | #endif |
| 62 | *dst++ = '\\'; |
| 63 | *dst++ = 'a'; |
| 64 | goto done; |
| 65 | case '\v': |
| 66 | *dst++ = '\\'; |
| 67 | *dst++ = 'v'; |
| 68 | goto done; |
| 69 | case '\t': |
| 70 | *dst++ = '\\'; |
| 71 | *dst++ = 't'; |
| 72 | goto done; |
| 73 | case '\f': |
| 74 | *dst++ = '\\'; |
| 75 | *dst++ = 'f'; |
| 76 | goto done; |
| 77 | case ' ': |
| 78 | *dst++ = '\\'; |
| 79 | *dst++ = 's'; |
| 80 | goto done; |
| 81 | case '\0': |
| 82 | *dst++ = '\\'; |
| 83 | *dst++ = '0'; |
| 84 | if (isoctal(nextc)) { |
| 85 | *dst++ = '0'; |
| 86 | *dst++ = '0'; |
| 87 | } |
| 88 | goto done; |
| 89 | } |
| 90 | } |
| 91 | if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) { |
| 92 | *dst++ = '\\'; |
| 93 | *dst++ = ((u_char)c >> 6 & 07) + '0'; |
| 94 | *dst++ = ((u_char)c >> 3 & 07) + '0'; |
| 95 | *dst++ = ((u_char)c & 07) + '0'; |
| 96 | goto done; |
| 97 | } |
| 98 | if ((flag & VIS_NOSLASH) == 0) |
| 99 | *dst++ = '\\'; |
| 100 | if (c & 0200) { |
| 101 | c &= 0177; |
| 102 | *dst++ = 'M'; |
| 103 | } |
| 104 | if (iscntrl(c)) { |
| 105 | *dst++ = '^'; |
| 106 | if (c == 0177) |
| 107 | *dst++ = '?'; |
| 108 | else |
| 109 | *dst++ = c + '@'; |
| 110 | } else { |
| 111 | *dst++ = '-'; |
| 112 | *dst++ = c; |
| 113 | } |
| 114 | done: |
| 115 | *dst = '\0'; |
| 116 | return (dst); |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * strvis, strvisx - visually encode characters from src into dst |
| 121 | * |
| 122 | * Dst must be 4 times the size of src to account for possible |
| 123 | * expansion. The length of dst, not including the trailing NULL, |
| 124 | * is returned. |
| 125 | * |
| 126 | * Strvisx encodes exactly len bytes from src into dst. |
| 127 | * This is useful for encoding a block of data. |
| 128 | */ |
| 129 | int |
| 130 | strvis(dst, src, flag) |
| 131 | register char *dst; |
| 132 | register const char *src; |
| 133 | int flag; |
| 134 | { |
| 135 | register char c; |
| 136 | char *start = dst; |
| 137 | |
| 138 | for (;c = *src; src++) |
| 139 | dst = vis(dst, c, flag, *(src+1)); |
| 140 | |
| 141 | return (dst - start); |
| 142 | } |
| 143 | |
| 144 | int |
| 145 | strvisx(dst, src, len, flag) |
| 146 | register char *dst; |
| 147 | register const char *src; |
| 148 | register size_t len; |
| 149 | int flag; |
| 150 | { |
| 151 | char *start = dst; |
| 152 | |
| 153 | while (len > 1) { |
| 154 | dst = vis(dst, *src, flag, *(src+1)); |
| 155 | len--; |
| 156 | } |
| 157 | if (len) |
| 158 | dst = vis(dst, *src, flag, '\0'); |
| 159 | |
| 160 | return (dst - start); |
| 161 | } |