From: Ralph Corderoy <ralph@inputplus.co.uk>
Date: Tue, 9 May 2017 21:48:11 +0000 (+0100)
Subject: sbr/mf.c: Simplify isat();  it's /^ at /i.
X-Git-Url: https://diplodocus.org/git/nmh/commitdiff_plain/d8f618fee89be7c25e9cc232a358d2d2b1ed53ac?hp=7cca9c4da3b90561d4cdf7de97f534d6c98ae1f4

sbr/mf.c: Simplify isat();  it's /^ at /i.

This one's for all those RFC 733 emails out there.
You know who you are.
---

diff --git a/sbr/mf.c b/sbr/mf.c
index 4d04abb6..33eed0d1 100644
--- a/sbr/mf.c
+++ b/sbr/mf.c
@@ -24,8 +24,10 @@ static int my_lex (char *);
 static int
 isat (const char *p)
 {
-    return has_prefix(p, " AT ") || has_prefix(p, " At ") ||
-        has_prefix(p, " aT ") || has_prefix(p, " at ");
+    return *p == ' ' &&
+        (p[1] == 'a' || p[1] == 'A') &&
+        (p[2] == 't' || p[2] == 'T') &&
+        p[3] == ' ';
 }