Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "quote.h"
   3
   4/* Help to copy the thing properly quoted for the shell safety.
   5 * any single quote is replaced with '\'', any exclamation point
   6 * is replaced with '\!', and the whole thing is enclosed in a
   7 *
   8 * E.g.
   9 *  original     sq_quote     result
  10 *  name     ==> name      ==> 'name'
  11 *  a b      ==> a b       ==> 'a b'
  12 *  a'b      ==> a'\''b    ==> 'a'\''b'
  13 *  a!b      ==> a'\!'b    ==> 'a'\!'b'
  14 */
  15#undef EMIT
  16#define EMIT(x) do { if (++len < n) *bp++ = (x); } while(0)
  17
  18static inline int need_bs_quote(char c)
  19{
  20        return (c == '\'' || c == '!');
  21}
  22
  23size_t sq_quote_buf(char *dst, size_t n, const char *src)
  24{
  25        char c;
  26        char *bp = dst;
  27        size_t len = 0;
  28
  29        EMIT('\'');
  30        while ((c = *src++)) {
  31                if (need_bs_quote(c)) {
  32                        EMIT('\'');
  33                        EMIT('\\');
  34                        EMIT(c);
  35                        EMIT('\'');
  36                } else {
  37                        EMIT(c);
  38                }
  39        }
  40        EMIT('\'');
  41
  42        if ( n )
  43                *bp = 0;
  44
  45        return len;
  46}
  47
  48void sq_quote_print(FILE *stream, const char *src)
  49{
  50        char c;
  51
  52        fputc('\'', stream);
  53        while ((c = *src++)) {
  54                if (need_bs_quote(c)) {
  55                        fputs("'\\", stream);
  56                        fputc(c, stream);
  57                        fputc('\'', stream);
  58                } else {
  59                        fputc(c, stream);
  60                }
  61        }
  62        fputc('\'', stream);
  63}
  64
  65char *sq_quote(const char *src)
  66{
  67        char *buf;
  68        size_t cnt;
  69
  70        cnt = sq_quote_buf(NULL, 0, src) + 1;
  71        buf = xmalloc(cnt);
  72        sq_quote_buf(buf, cnt, src);
  73
  74        return buf;
  75}
  76
  77char *sq_dequote(char *arg)
  78{
  79        char *dst = arg;
  80        char *src = arg;
  81        char c;
  82
  83        if (*src != '\'')
  84                return NULL;
  85        for (;;) {
  86                c = *++src;
  87                if (!c)
  88                        return NULL;
  89                if (c != '\'') {
  90                        *dst++ = c;
  91                        continue;
  92                }
  93                /* We stepped out of sq */
  94                switch (*++src) {
  95                case '\0':
  96                        *dst = 0;
  97                        return arg;
  98                case '\\':
  99                        c = *++src;
 100                        if (need_bs_quote(c) && *++src == '\'') {
 101                                *dst++ = c;
 102                                continue;
 103                        }
 104                /* Fallthrough */
 105                default:
 106                        return NULL;
 107                }
 108        }
 109}
 110
 111/*
 112 * C-style name quoting.
 113 *
 114 * Does one of three things:
 115 *
 116 * (1) if outbuf and outfp are both NULL, inspect the input name and
 117 *     counts the number of bytes that are needed to hold c_style
 118 *     quoted version of name, counting the double quotes around
 119 *     it but not terminating NUL, and returns it.  However, if name
 120 *     does not need c_style quoting, it returns 0.
 121 *
 122 * (2) if outbuf is not NULL, it must point at a buffer large enough
 123 *     to hold the c_style quoted version of name, enclosing double
 124 *     quotes, and terminating NUL.  Fills outbuf with c_style quoted
 125 *     version of name enclosed in double-quote pair.  Return value
 126 *     is undefined.
 127 *
 128 * (3) if outfp is not NULL, outputs c_style quoted version of name,
 129 *     but not enclosed in double-quote pair.  Return value is undefined.
 130 */
 131
 132static int quote_c_style_counted(const char *name, int namelen,
 133                                 char *outbuf, FILE *outfp, int no_dq)
 134{
 135#undef EMIT
 136#define EMIT(c) \
 137        (outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
 138
 139#define EMITQ() EMIT('\\')
 140
 141        const char *sp;
 142        int ch, count = 0, needquote = 0;
 143
 144        if (!no_dq)
 145                EMIT('"');
 146        for (sp = name; sp < name + namelen; sp++) {
 147                ch = *sp;
 148                if (!ch)
 149                        break;
 150                if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
 151                    (ch == 0177)) {
 152                        needquote = 1;
 153                        switch (ch) {
 154                        case '\a': EMITQ(); ch = 'a'; break;
 155                        case '\b': EMITQ(); ch = 'b'; break;
 156                        case '\f': EMITQ(); ch = 'f'; break;
 157                        case '\n': EMITQ(); ch = 'n'; break;
 158                        case '\r': EMITQ(); ch = 'r'; break;
 159                        case '\t': EMITQ(); ch = 't'; break;
 160                        case '\v': EMITQ(); ch = 'v'; break;
 161
 162                        case '\\': /* fallthru */
 163                        case '"': EMITQ(); break;
 164                        default:
 165                                /* octal */
 166                                EMITQ();
 167                                EMIT(((ch >> 6) & 03) + '0');
 168                                EMIT(((ch >> 3) & 07) + '0');
 169                                ch = (ch & 07) + '0';
 170                                break;
 171                        }
 172                }
 173                EMIT(ch);
 174        }
 175        if (!no_dq)
 176                EMIT('"');
 177        if (outbuf)
 178                *outbuf = 0;
 179
 180        return needquote ? count : 0;
 181}
 182
 183int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
 184{
 185        int cnt = strlen(name);
 186        return quote_c_style_counted(name, cnt, outbuf, outfp, no_dq);
 187}
 188
 189/*
 190 * C-style name unquoting.
 191 *
 192 * Quoted should point at the opening double quote.  Returns
 193 * an allocated memory that holds unquoted name, which the caller
 194 * should free when done.  Updates endp pointer to point at
 195 * one past the ending double quote if given.
 196 */
 197
 198char *unquote_c_style(const char *quoted, const char **endp)
 199{
 200        const char *sp;
 201        char *name = NULL, *outp = NULL;
 202        int count = 0, ch, ac;
 203
 204#undef EMIT
 205#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
 206
 207        if (*quoted++ != '"')
 208                return NULL;
 209
 210        while (1) {
 211                /* first pass counts and allocates, second pass fills */
 212                for (sp = quoted; (ch = *sp++) != '"'; ) {
 213                        if (ch == '\\') {
 214                                switch (ch = *sp++) {
 215                                case 'a': ch = '\a'; break;
 216                                case 'b': ch = '\b'; break;
 217                                case 'f': ch = '\f'; break;
 218                                case 'n': ch = '\n'; break;
 219                                case 'r': ch = '\r'; break;
 220                                case 't': ch = '\t'; break;
 221                                case 'v': ch = '\v'; break;
 222
 223                                case '\\': case '"':
 224                                        break; /* verbatim */
 225
 226                                case '0':
 227                                case '1':
 228                                case '2':
 229                                case '3':
 230                                case '4':
 231                                case '5':
 232                                case '6':
 233                                case '7':
 234                                        /* octal */
 235                                        ac = ((ch - '0') << 6);
 236                                        if ((ch = *sp++) < '0' || '7' < ch)
 237                                                return NULL;
 238                                        ac |= ((ch - '0') << 3);
 239                                        if ((ch = *sp++) < '0' || '7' < ch)
 240                                                return NULL;
 241                                        ac |= (ch - '0');
 242                                        ch = ac;
 243                                        break;
 244                                default:
 245                                        return NULL; /* malformed */
 246                                }
 247                        }
 248                        EMIT(ch);
 249                }
 250
 251                if (name) {
 252                        *outp = 0;
 253                        if (endp)
 254                                *endp = sp;
 255                        return name;
 256                }
 257                outp = name = xmalloc(count + 1);
 258        }
 259}
 260
 261void write_name_quoted(const char *prefix, int prefix_len,
 262                       const char *name, int quote, FILE *out)
 263{
 264        int needquote;
 265
 266        if (!quote) {
 267        no_quote:
 268                if (prefix_len)
 269                        fprintf(out, "%.*s", prefix_len, prefix);
 270                fputs(name, out);
 271                return;
 272        }
 273
 274        needquote = 0;
 275        if (prefix_len)
 276                needquote = quote_c_style_counted(prefix, prefix_len,
 277                                                  NULL, NULL, 0);
 278        if (!needquote)
 279                needquote = quote_c_style(name, NULL, NULL, 0);
 280        if (needquote) {
 281                fputc('"', out);
 282                if (prefix_len)
 283                        quote_c_style_counted(prefix, prefix_len,
 284                                              NULL, out, 1);
 285                quote_c_style(name, NULL, out, 1);
 286                fputc('"', out);
 287        }
 288        else
 289                goto no_quote;
 290}