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) ( (++len < n) && (*bp++ = (x)) )
  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
  48char *sq_quote(const char *src)
  49{
  50        char *buf;
  51        size_t cnt;
  52
  53        cnt = sq_quote_buf(NULL, 0, src) + 1;
  54        buf = xmalloc(cnt);
  55        sq_quote_buf(buf, cnt, src);
  56
  57        return buf;
  58}
  59
  60char *sq_dequote(char *arg)
  61{
  62        char *dst = arg;
  63        char *src = arg;
  64        char c;
  65
  66        if (*src != '\'')
  67                return NULL;
  68        for (;;) {
  69                c = *++src;
  70                if (!c)
  71                        return NULL;
  72                if (c != '\'') {
  73                        *dst++ = c;
  74                        continue;
  75                }
  76                /* We stepped out of sq */
  77                switch (*++src) {
  78                case '\0':
  79                        *dst = 0;
  80                        return arg;
  81                case '\\':
  82                        c = *++src;
  83                        if (need_bs_quote(c) && *++src == '\'') {
  84                                *dst++ = c;
  85                                continue;
  86                        }
  87                /* Fallthrough */
  88                default:
  89                        return NULL;
  90                }
  91        }
  92}
  93
  94/*
  95 * C-style name quoting.
  96 *
  97 * Does one of three things:
  98 *
  99 * (1) if outbuf and outfp are both NULL, inspect the input name and
 100 *     counts the number of bytes that are needed to hold c_style
 101 *     quoted version of name, counting the double quotes around
 102 *     it but not terminating NUL, and returns it.  However, if name
 103 *     does not need c_style quoting, it returns 0.
 104 *
 105 * (2) if outbuf is not NULL, it must point at a buffer large enough
 106 *     to hold the c_style quoted version of name, enclosing double
 107 *     quotes, and terminating NUL.  Fills outbuf with c_style quoted
 108 *     version of name enclosed in double-quote pair.  Return value
 109 *     is undefined.
 110 *
 111 * (3) if outfp is not NULL, outputs c_style quoted version of name,
 112 *     but not enclosed in double-quote pair.  Return value is undefined.
 113 */
 114
 115int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
 116{
 117#undef EMIT
 118#define EMIT(c) \
 119        (outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
 120
 121#define EMITQ() EMIT('\\')
 122
 123        const char *sp;
 124        int ch, count = 0, needquote = 0;
 125
 126        if (!no_dq)
 127                EMIT('"');
 128        for (sp = name; (ch = *sp++); ) {
 129
 130                if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
 131                    (ch == 0177)) {
 132                        needquote = 1;
 133                        switch (ch) {
 134                        case '\a': EMITQ(); ch = 'a'; break;
 135                        case '\b': EMITQ(); ch = 'b'; break;
 136                        case '\f': EMITQ(); ch = 'f'; break;
 137                        case '\n': EMITQ(); ch = 'n'; break;
 138                        case '\r': EMITQ(); ch = 'r'; break;
 139                        case '\t': EMITQ(); ch = 't'; break;
 140                        case '\v': EMITQ(); ch = 'v'; break;
 141
 142                        case '\\': /* fallthru */
 143                        case '"': EMITQ(); break;
 144                        case ' ':
 145                                break;
 146                        default:
 147                                /* octal */
 148                                EMITQ();
 149                                EMIT(((ch >> 6) & 03) + '0');
 150                                EMIT(((ch >> 3) & 07) + '0');
 151                                ch = (ch & 07) + '0';
 152                                break;
 153                        }
 154                }
 155                EMIT(ch);
 156        }
 157        if (!no_dq)
 158                EMIT('"');
 159        if (outbuf)
 160                *outbuf = 0;
 161
 162        return needquote ? count : 0;
 163}
 164
 165/*
 166 * C-style name unquoting.
 167 *
 168 * Quoted should point at the opening double quote.  Returns
 169 * an allocated memory that holds unquoted name, which the caller
 170 * should free when done.  Updates endp pointer to point at
 171 * one past the ending double quote if given.
 172 */
 173
 174char *unquote_c_style(const char *quoted, const char **endp)
 175{
 176        const char *sp;
 177        char *name = NULL, *outp = NULL;
 178        int count = 0, ch, ac;
 179
 180#undef EMIT
 181#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
 182
 183        if (*quoted++ != '"')
 184                return NULL;
 185
 186        while (1) {
 187                /* first pass counts and allocates, second pass fills */
 188                for (sp = quoted; (ch = *sp++) != '"'; ) {
 189                        if (ch == '\\') {
 190                                switch (ch = *sp++) {
 191                                case 'a': ch = '\a'; break;
 192                                case 'b': ch = '\b'; break;
 193                                case 'f': ch = '\f'; break;
 194                                case 'n': ch = '\n'; break;
 195                                case 'r': ch = '\r'; break;
 196                                case 't': ch = '\t'; break;
 197                                case 'v': ch = '\v'; break;
 198
 199                                case '\\': case '"':
 200                                        break; /* verbatim */
 201
 202                                case '0'...'7':
 203                                        /* octal */
 204                                        ac = ((ch - '0') << 6);
 205                                        if ((ch = *sp++) < '0' || '7' < ch)
 206                                                return NULL;
 207                                        ac |= ((ch - '0') << 3);
 208                                        if ((ch = *sp++) < '0' || '7' < ch)
 209                                                return NULL;
 210                                        ac |= (ch - '0');
 211                                        ch = ac;
 212                                        break;
 213                                default:
 214                                        return NULL; /* malformed */
 215                                }
 216                        }
 217                        EMIT(ch);
 218                }
 219
 220                if (name) {
 221                        *outp = 0;
 222                        if (endp)
 223                                *endp = sp;
 224                        return name;
 225                }
 226                outp = name = xmalloc(count + 1);
 227        }
 228}
 229
 230void write_name_quoted(const char *prefix, const char *name,
 231                       int quote, FILE *out)
 232{
 233        int needquote;
 234
 235        if (!quote) {
 236        no_quote:
 237                if (prefix && prefix[0])
 238                        fputs(prefix, out);
 239                fputs(name, out);
 240                return;
 241        }
 242
 243        needquote = 0;
 244        if (prefix && prefix[0])
 245                needquote = quote_c_style(prefix, NULL, NULL, 0);
 246        if (!needquote)
 247                needquote = quote_c_style(name, NULL, NULL, 0);
 248        if (needquote) {
 249                fputc('"', out);
 250                if (prefix && prefix[0])
 251                        quote_c_style(prefix, NULL, out, 1);
 252                quote_c_style(name, NULL, out, 1);
 253                fputc('"', out);
 254        }
 255        else
 256                goto no_quote;
 257}