Add expansion item for sorting lists

[exim.git] / src / src / expand.c

diff --git a/src/src/expand.c b/src/src/expand.c
index a929e937c05c8fe5175406e481998675322cca03..8e94c3e4b67edbe1ddb57e6e294815aecf1f96aa 100644 (file)
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -127,6 +127,7 @@ static uschar *item_table[] = {
   US"reduce",
   US"run",
   US"sg",
+  US"sort",
   US"substr",
   US"tr" };
 
@@ -152,6 +153,7 @@ enum {
   EITEM_REDUCE,
   EITEM_RUN,
   EITEM_SG,
+  EITEM_SORT,
   EITEM_SUBSTR,
   EITEM_TR };
 
@@ -5633,6 +5635,145 @@ while (*s != 0)
       continue;
       }
 
+    case EITEM_SORT:
+      {
+      int sep = 0;
+      uschar *srclist, *cmp, *xtract;
+      uschar *srcitem;
+      uschar *dstlist = NULL;
+      uschar *dstkeylist = NULL;
+      uschar * tmp;
+      uschar *save_iterate_item = iterate_item;
+
+      while (isspace(*s)) s++;
+      if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+
+      srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
+      if (!srclist) goto EXPAND_FAILED;
+      if (*s++ != '}') goto EXPAND_FAILED_CURLY;
+
+      while (isspace(*s)) s++;
+      if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+
+      cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
+      if (!cmp) goto EXPAND_FAILED;
+      if (*s++ != '}') goto EXPAND_FAILED_CURLY;
+
+      while (isspace(*s)) s++;
+      if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+
+      xtract = s;
+      tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
+      if (!tmp) goto EXPAND_FAILED;
+      xtract = string_copyn(xtract, s - xtract);
+
+      if (*s++ != '}') goto EXPAND_FAILED_CURLY;
+                                                       /*{*/
+      if (*s++ != '}')
+        {                                              /*{*/
+        expand_string_message = US"missing } at end of \"sort\"";
+        goto EXPAND_FAILED;
+        }
+
+      if (skipping) continue;
+
+      while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
+        {
+       uschar * dstitem;
+       uschar * newlist = NULL;
+       uschar * newkeylist = NULL;
+       uschar * srcfield;
+
+        DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
+
+       /* extract field for comparisons */
+       iterate_item = srcitem;
+       if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
+                                         TRUE, &resetok))
+          || !*srcfield)
+         {
+         expand_string_message = string_sprintf(
+             "field-extract in sort: \"%s\"", xtract);
+         goto EXPAND_FAILED;
+         }
+
+       /* Insertion sort */
+
+       /* copy output list until new-item < list-item */
+       while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
+         {
+         uschar * dstfield;
+         uschar * expr;
+         BOOL before;
+
+         /* field for comparison */
+         if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
+           goto sort_mismatch;
+
+         /* build and run condition string */
+         expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
+
+         DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
+         if (!eval_condition(expr, &resetok, &before))
+           {
+           expand_string_message = string_sprintf("comparison in sort: %s",
+               expr);
+           goto EXPAND_FAILED;
+           }
+
+         if (before)
+           {
+           /* New-item sorts before this dst-item.  Append new-item,
+           then dst-item, then remainder of dst list. */
+
+           newlist = string_append_listele(newlist, sep, srcitem);
+           newkeylist = string_append_listele(newkeylist, sep, srcfield);
+           srcitem = NULL;
+
+           newlist = string_append_listele(newlist, sep, dstitem);
+           newkeylist = string_append_listele(newkeylist, sep, dstfield);
+
+           while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
+             {
+             if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
+               goto sort_mismatch;
+             newlist = string_append_listele(newlist, sep, dstitem);
+             newkeylist = string_append_listele(newkeylist, sep, dstfield);
+             }
+
+           break;
+           }
+
+         newlist = string_append_listele(newlist, sep, dstitem);
+         newkeylist = string_append_listele(newkeylist, sep, dstfield);
+         }
+
+       /* If we ran out of dstlist without consuming srcitem, append it */
+       if (srcitem)
+         {
+         newlist = string_append_listele(newlist, sep, srcitem);
+         newkeylist = string_append_listele(newkeylist, sep, srcfield);
+         }
+
+       dstlist = newlist;
+       dstkeylist = newkeylist;
+
+        DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
+        DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
+       }
+
+      if (dstlist)
+       yield = string_cat(yield, &size, &ptr, dstlist, Ustrlen(dstlist));
+
+      /* Restore preserved $item */
+      iterate_item = save_iterate_item;
+      continue;
+
+      sort_mismatch:
+       expand_string_message = US"Internal error in sort (list mismatch)";
+       goto EXPAND_FAILED;
+      }
+
 
     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}