Make vorbis comment helper functions generic.

[paraslash.git] / string.c

diff --git a/string.c b/string.c
index cefb45d674075cf1fcb2e42b42e5b0a929a52c16..f7d70353db977d6543055c19c7bd68a17b83a3ce 100644 (file)
--- a/string.c
+++ b/string.c
@@ -793,3 +793,56 @@ int para_regcomp(regex_t *preg, const char *regex, int cflags)
        free(buf);
        return -E_REGEX;
 }
        free(buf);
        return -E_REGEX;
 }

+
+/**
+ * strdup() for not necessarily zero-terminated strings.
+ *
+ * \param src The source buffer.
+ * \param len The number of bytes to be copied.
+ *
+ * \return A 0-terminated buffer of length \a len + 1.
+ *
+ * This is similar to strndup(), which is a GNU extension. However, one
+ * difference is that strndup() returns \p NULL if insufficient memory was
+ * available while this function aborts in this case.
+ *
+ * \sa strdup(), \ref para_strdup().
+ */
+char *safe_strdup(const char *src, size_t len)
+{
+       char *p;
+
+       assert(len < (size_t)-1);
+       p = para_malloc(len + 1);
+       if (len > 0)
+               memcpy(p, src, len);
+       p[len] = '\0';
+       return p;
+}
+
+/**
+ * Copy the value of a key=value pair.
+ *
+ * This checks whether the given buffer starts with "key=", ignoring case. If
+ * yes, a copy of the value is returned. The source buffer may not be
+ * zero-terminated.
+ *
+ * \param src The source buffer.
+ * \param len The number of bytes of the tag.
+ * \param key Only copy if it is the value of this key.
+ *
+ * \return A zero-terminated buffer, or \p NULL if the key was
+ * not of the given type.
+ */
+char *key_value_copy(const char *src, size_t len, const char *key)
+{
+       int keylen = strlen(key);
+
+       if (len <= keylen)
+               return NULL;
+       if (strncasecmp(src, key, keylen))
+               return NULL;
+       if (src[keylen] != '=')
+               return NULL;
+       return safe_strdup(src + keylen + 1, len - keylen - 1);
+}