[FFmpeg-devel] [PATCH 2/4] Make strmatch() return 1 only if the string compared against the prefix does not contain other characters which may belong to an identifier.

[Stefano Sabatini]

This allows to distinguish for example to have different constants
with the same prefix (e.g. "foo" and "foobar").
---
 libavutil/eval.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/libavutil/eval.c b/libavutil/eval.c
index 6e03498..27c1b6d 100644
--- a/libavutil/eval.c
+++ b/libavutil/eval.c
@@ -103,13 +103,15 @@ double av_strtod(const char *numstr, char **tail)
     return d;
 }
 
+#define IDENTIFIER_CHARS "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789"
+
 static int strmatch(const char *s, const char *prefix)
 {
     int i;
     for (i=0; prefix[i]; i++) {
         if (prefix[i] != s[i]) return 0;
     }
-    return 1;
+    return !strspn(s+i, IDENTIFIER_CHARS);
 }
 
 struct AVExpr {
-- 
1.7.1