--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/quote.c	Fri Oct 19 14:06:22 2007 +0200
@@ -0,0 +1,83 @@
+#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(saout,sain)
+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(s,n)
+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(saout,sain)
+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(sa,s)
+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);
+}