[Qemu-devel] [PATCH 1/3] make path_has_protocol() to return pointer instead of bool

[Michael Tokarev <mjt@tls.msk.ru>]

Currently protocol: parsing in filenames is ad-hoc and scattered all around
block.c.  This is a first step to prepare for common parsing.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---
 block.c |   18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index ff2795b..e5a6f60 100644
--- a/block.c
+++ b/block.c
@@ -90,9 +90,11 @@ int is_windows_drive(const char *filename)
 }
 #endif
 
-/* check if the path starts with "<protocol>:" */
-static int path_has_protocol(const char *path)
+/* check if the path starts with "<protocol>:"
+ * Return pointer to the leading colon or NULL */
+static char *path_has_protocol(const char *path)
 {
+    const char *p;
 #ifdef _WIN32
     if (is_windows_drive(path) ||
         is_windows_drive_prefix(path)) {
@@ -100,7 +102,17 @@ static int path_has_protocol(const char *path)
     }
 #endif
 
-    return strchr(path, ':') != NULL;
+    p = path;
+    /* we allow [a-z_] for now */
+    while((*p >= 'a' && *p <= 'z') || *p == '_') {
+        ++p;
+    }
+
+#define MAX_PROTO_LEN 31
+    /* recognize non-empty string of max MAX_PROTO chars as protocol */
+    return
+        *p == ':' && p > path && (p - path) <= MAX_PROTO_LEN ?
+            (char*)p : NULL;
 }
 
 int path_is_absolute(const char *path)
-- 
1.7.2.3