1 files changed, 81 insertions, 0 deletions
diff --git a/src/quote.c b/src/quote.c
new file mode 100644
index 0000000..ef1bf45
--- /dev/null
+++ b/src/quote.c
@@ -0,0 +1,81 @@
+#include "stralloc.h"
+#include "str.h"
+#include "quote.h"
+
+/*
+quote() encodes a box as per rfc 821 and rfc 822,
+while trying to do as little quoting as possible.
+no, 821 and 822 don't have the same encoding. they're not even close.
+no special encoding here for bytes above 127.
+*/
+
+static char ok[128] = {
+ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+,0,7,0,7,7,7,7,7,0,0,7,7,0,7,7,7 ,7,7,7,7,7,7,7,7,7,7,0,0,0,7,0,7
+,0,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 ,7,7,7,7,7,7,7,7,7,7,7,0,0,0,7,7
+,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 ,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,0
+} ;
+
+static int doit(stralloc *saout,stralloc *sain)
+{
+  char ch;
+  int i;
+  int j;
+
+  if (!stralloc_ready(saout,sain->len * 2 + 2)) return 0;
+  j = 0;
+  saout->s[j++] = '"';
+
+  for (i = 0; i < sain->len; ++i) {
+    ch = sain->s[i];
+    if ((ch == '\r') || (ch == '\n') || (ch == '"') || (ch == '\\'))
+      saout->s[j++] = '\\';
+    saout->s[j++] = ch;
+  }
+  saout->s[j++] = '"';
+  saout->len = j;
+
+  return 1;
+}
+
+int quote_need(char *s,unsigned int n)
+{
+  unsigned char uch;
+  int i;
+  if (!n) return 1;
+
+  for (i = 0; i < n; ++i) {
+    uch = s[i];
+    if (uch >= 128) return 1;
+    if (!ok[uch]) return 1;
+  }
+  if (s[0] == '.') return 1;
+  if (s[n - 1] == '.') return 1;
+
+  for (i = 0; i < n - 1; ++i) 
+    if (s[i] == '.') 
+      if (s[i + 1] == '.') return 1;
+
+  return 0;
+}
+
+int quote(stralloc *saout,stralloc *sain)
+{
+  if (quote_need(sain->s,sain->len)) return doit(saout,sain);
+  return stralloc_copy(saout,sain);
+}
+
+static stralloc foo = {0};
+
+int quote2(stralloc *sa,char *s)
+{
+  int j;
+  if (!*s) return stralloc_copys(sa,s);
+  j = str_rchr(s,'@');
+  if (!stralloc_copys(&foo,s)) return 0;
+  if (!s[j]) return quote(sa,&foo);
+  foo.len = j;
+  if (!quote(sa,&foo)) return 0;
+
+  return stralloc_cats(sa,s + j);
+}