[PATCH v2 5/8] http: optionally extract charset parameter from content-type

From

Jeff King <peff@peff.net>

Date

May 22, 2014, 09:30 UTC

Message-ID

<20140522093005.GE15032@sigill.intra.peff.net>

In-Reply-To

<20140522092824.GA14530@sigill.intra.peff.net>

  1. That complicates the interface and memory management.

  2. In practice, no planned callers care about anything
     except the charset.

Signed-off-by: Jeff King <peff@peff.net>
---
 http.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 http.h |  7 +++++++
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/http.c b/http.c
index 4edf5b9..e26ee8b 100644
--- a/http.c
+++ b/http.c
@@ -907,14 +907,44 @@ static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 }
 
 /*
+ * Check for and extract a content-type parameter. "raw"
+ * should be positioned at the start of the potential
+ * parameter, with any whitespace already removed.
+ *
+ * "name" is the name of the parameter. The value is appended
+ * to "out".
+ */
+static int extract_param(const char *raw, const char *name,
+			 struct strbuf *out)
+{
+	size_t len = strlen(name);
+
+	if (strncasecmp(raw, name, len))
+		return -1;
+	raw += len;
+
+	if (*raw != '=')
+		return -1;
+	raw++;
+
+	while (*raw && !isspace(*raw))
+		strbuf_addch(out, *raw++);
+	return 0;
+}
+
+/*
  * Extract a normalized version of the content type, with any
  * spaces suppressed, all letters lowercased, and no trailing ";"
  * or parameters.
  *
+ * If the "charset" argument is not NULL, store the value of any
+ * charset parameter there.
+ *
  * Example:
- *   "TEXT/PLAIN; charset=utf-8" -> "text/plain"
+ *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
  */
-static void extract_content_type(struct strbuf *raw, struct strbuf *type)
+static void extract_content_type(struct strbuf *raw, struct strbuf *type,
+				 struct strbuf *charset)
 {
 	const char *p;
 
@@ -923,10 +953,25 @@ static void extract_content_type(struct strbuf *raw, struct strbuf *type)
 	for (p = raw->buf; *p; p++) {
 		if (isspace(*p))
 			continue;
-		if (*p == ';')
+		if (*p == ';') {
+			p++;
 			break;
+		}
 		strbuf_addch(type, tolower(*p));
 	}
+
+	if (!charset)
+		return;
+
+	strbuf_reset(charset);
+	while (*p) {
+		while (isspace(*p))
+			p++;
+		if (!extract_param(p, "charset", charset))
+			return;
+		while (*p && !isspace(*p))
+			p++;
+	}
 }
 
 /* http_request() targets */
@@ -983,7 +1028,8 @@ static int http_request(const char *url,
 	if (options && options->content_type) {
 		struct strbuf raw = STRBUF_INIT;
 		curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
-		extract_content_type(&raw, options->content_type);
+		extract_content_type(&raw, options->content_type,
+				     options->charset);
 		strbuf_release(&raw);
 	}
 
diff --git a/http.h b/http.h
index e64084f..473179b 100644
--- a/http.h
+++ b/http.h
@@ -144,6 +144,13 @@ struct http_get_options {
 	struct strbuf *content_type;
 
 	/*
+	 * If non-NULL, and content_type above is non-NULL, returns
+	 * the charset parameter from the content-type. If none is
+	 * present, returns an empty string.
+	 */
+	struct strbuf *charset;
+
+	/*
 	 * If non-NULL, returns the URL we ended up at, including any
 	 * redirects we followed.
 	 */

-- 
2.0.0.rc1.436.g03cb729