Merge branch 'ew/send-email'
[gitweb.git] / quote.c
diff --git a/quote.c b/quote.c
index 5e6fda311c5f5fdaa20b7e9d64e46c13b7d9cce8..06792d47c3e324ee9893a4e52035f0642f38005f 100644 (file)
--- a/quote.c
+++ b/quote.c
 #include "quote.h"
 
 /* Help to copy the thing properly quoted for the shell safety.
- * any single quote is replaced with '\'', and the caller is
- * expected to enclose the result within a single quote pair.
+ * any single quote is replaced with '\'', any exclamation point
+ * is replaced with '\!', and the whole thing is enclosed in a
  *
  * E.g.
  *  original     sq_quote     result
  *  name     ==> name      ==> 'name'
  *  a b      ==> a b       ==> 'a b'
  *  a'b      ==> a'\''b    ==> 'a'\''b'
+ *  a!b      ==> a'\!'b    ==> 'a'\!'b'
  */
-char *sq_quote(const char *src)
+#undef EMIT
+#define EMIT(x) ( (++len < n) && (*bp++ = (x)) )
+
+static inline int need_bs_quote(char c)
 {
-       static char *buf = NULL;
-       int cnt, c;
-       const char *cp;
-       char *bp;
+       return (c == '\'' || c == '!');
+}
 
-       /* count bytes needed to store the quoted string. */
-       for (cnt = 3, cp = src; *cp; cnt++, cp++)
-               if (*cp == '\'')
-                       cnt += 3;
+size_t sq_quote_buf(char *dst, size_t n, const char *src)
+{
+       char c;
+       char *bp = dst;
+       size_t len = 0;
 
-       buf = xmalloc(cnt);
-       bp = buf;
-       *bp++ = '\'';
+       EMIT('\'');
        while ((c = *src++)) {
-               if (c != '\'')
-                       *bp++ = c;
-               else {
-                       bp = strcpy(bp, "'\\''");
-                       bp += 4;
+               if (need_bs_quote(c)) {
+                       EMIT('\'');
+                       EMIT('\\');
+                       EMIT(c);
+                       EMIT('\'');
+               } else {
+                       EMIT(c);
                }
        }
-       *bp++ = '\'';
-       *bp = 0;
+       EMIT('\'');
+
+       if ( n )
+               *bp = 0;
+
+       return len;
+}
+
+char *sq_quote(const char *src)
+{
+       char *buf;
+       size_t cnt;
+
+       cnt = sq_quote_buf(NULL, 0, src) + 1;
+       buf = xmalloc(cnt);
+       sq_quote_buf(buf, cnt, src);
+
        return buf;
 }
 
+char *sq_dequote(char *arg)
+{
+       char *dst = arg;
+       char *src = arg;
+       char c;
+
+       if (*src != '\'')
+               return NULL;
+       for (;;) {
+               c = *++src;
+               if (!c)
+                       return NULL;
+               if (c != '\'') {
+                       *dst++ = c;
+                       continue;
+               }
+               /* We stepped out of sq */
+               switch (*++src) {
+               case '\0':
+                       *dst = 0;
+                       return arg;
+               case '\\':
+                       c = *++src;
+                       if (need_bs_quote(c) && *++src == '\'') {
+                               *dst++ = c;
+                               continue;
+                       }
+               /* Fallthrough */
+               default:
+                       return NULL;
+               }
+       }
+}
+
+/*
+ * C-style name quoting.
+ *
+ * Does one of three things:
+ *
+ * (1) if outbuf and outfp are both NULL, inspect the input name and
+ *     counts the number of bytes that are needed to hold c_style
+ *     quoted version of name, counting the double quotes around
+ *     it but not terminating NUL, and returns it.  However, if name
+ *     does not need c_style quoting, it returns 0.
+ *
+ * (2) if outbuf is not NULL, it must point at a buffer large enough
+ *     to hold the c_style quoted version of name, enclosing double
+ *     quotes, and terminating NUL.  Fills outbuf with c_style quoted
+ *     version of name enclosed in double-quote pair.  Return value
+ *     is undefined.
+ *
+ * (3) if outfp is not NULL, outputs c_style quoted version of name,
+ *     but not enclosed in double-quote pair.  Return value is undefined.
+ */
+
+static int quote_c_style_counted(const char *name, int namelen,
+                                char *outbuf, FILE *outfp, int no_dq)
+{
+#undef EMIT
+#define EMIT(c) \
+       (outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
+
+#define EMITQ() EMIT('\\')
+
+       const char *sp;
+       int ch, count = 0, needquote = 0;
+
+       if (!no_dq)
+               EMIT('"');
+       for (sp = name; sp < name + namelen; sp++) {
+               ch = *sp;
+               if (!ch)
+                       break;
+               if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
+                   (ch == 0177)) {
+                       needquote = 1;
+                       switch (ch) {
+                       case '\a': EMITQ(); ch = 'a'; break;
+                       case '\b': EMITQ(); ch = 'b'; break;
+                       case '\f': EMITQ(); ch = 'f'; break;
+                       case '\n': EMITQ(); ch = 'n'; break;
+                       case '\r': EMITQ(); ch = 'r'; break;
+                       case '\t': EMITQ(); ch = 't'; break;
+                       case '\v': EMITQ(); ch = 'v'; break;
+
+                       case '\\': /* fallthru */
+                       case '"': EMITQ(); break;
+                       default:
+                               /* octal */
+                               EMITQ();
+                               EMIT(((ch >> 6) & 03) + '0');
+                               EMIT(((ch >> 3) & 07) + '0');
+                               ch = (ch & 07) + '0';
+                               break;
+                       }
+               }
+               EMIT(ch);
+       }
+       if (!no_dq)
+               EMIT('"');
+       if (outbuf)
+               *outbuf = 0;
+
+       return needquote ? count : 0;
+}
+
+int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
+{
+       int cnt = strlen(name);
+       return quote_c_style_counted(name, cnt, outbuf, outfp, no_dq);
+}
+
+/*
+ * C-style name unquoting.
+ *
+ * Quoted should point at the opening double quote.  Returns
+ * an allocated memory that holds unquoted name, which the caller
+ * should free when done.  Updates endp pointer to point at
+ * one past the ending double quote if given.
+ */
+
+char *unquote_c_style(const char *quoted, const char **endp)
+{
+       const char *sp;
+       char *name = NULL, *outp = NULL;
+       int count = 0, ch, ac;
+
+#undef EMIT
+#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
+
+       if (*quoted++ != '"')
+               return NULL;
+
+       while (1) {
+               /* first pass counts and allocates, second pass fills */
+               for (sp = quoted; (ch = *sp++) != '"'; ) {
+                       if (ch == '\\') {
+                               switch (ch = *sp++) {
+                               case 'a': ch = '\a'; break;
+                               case 'b': ch = '\b'; break;
+                               case 'f': ch = '\f'; break;
+                               case 'n': ch = '\n'; break;
+                               case 'r': ch = '\r'; break;
+                               case 't': ch = '\t'; break;
+                               case 'v': ch = '\v'; break;
+
+                               case '\\': case '"':
+                                       break; /* verbatim */
+
+                               case '0'...'7':
+                                       /* octal */
+                                       ac = ((ch - '0') << 6);
+                                       if ((ch = *sp++) < '0' || '7' < ch)
+                                               return NULL;
+                                       ac |= ((ch - '0') << 3);
+                                       if ((ch = *sp++) < '0' || '7' < ch)
+                                               return NULL;
+                                       ac |= (ch - '0');
+                                       ch = ac;
+                                       break;
+                               default:
+                                       return NULL; /* malformed */
+                               }
+                       }
+                       EMIT(ch);
+               }
+
+               if (name) {
+                       *outp = 0;
+                       if (endp)
+                               *endp = sp;
+                       return name;
+               }
+               outp = name = xmalloc(count + 1);
+       }
+}
+
+void write_name_quoted(const char *prefix, int prefix_len,
+                      const char *name, int quote, FILE *out)
+{
+       int needquote;
+
+       if (!quote) {
+       no_quote:
+               if (prefix_len)
+                       fprintf(out, "%.*s", prefix_len, prefix);
+               fputs(name, out);
+               return;
+       }
+
+       needquote = 0;
+       if (prefix_len)
+               needquote = quote_c_style_counted(prefix, prefix_len,
+                                                 NULL, NULL, 0);
+       if (!needquote)
+               needquote = quote_c_style(name, NULL, NULL, 0);
+       if (needquote) {
+               fputc('"', out);
+               if (prefix_len)
+                       quote_c_style_counted(prefix, prefix_len,
+                                             NULL, out, 1);
+               quote_c_style(name, NULL, out, 1);
+               fputc('"', out);
+       }
+       else
+               goto no_quote;
+}