4 files changed, 704 insertions, 471 deletions

diff --git a/include/wordsplit.h b/include/wordsplit.h
index a175275..d7eb26f 100644
--- a/include/wordsplit.h
+++ b/include/wordsplit.h
@@ -77,2 +77,12 @@ struct wordsplit
   size_t ws_envsiz;         /* Size of the ws_envbuf array */
+
+  char const **ws_paramv;   /* [WRDSO_PARAMV] User-supplied positional
+                               parameters */
+  size_t ws_paramc;         /* Number of positional parameters */
+
+        /* Temporary storage for parameters. Works similarly to ws_enbuf.
+         */
+  char **ws_parambuf;
+  size_t ws_paramidx;
+  size_t ws_paramsiz;
   
@@ -101,3 +111,3 @@ struct wordsplit
                                return values. */
-        
+
   const char *ws_input;     /* Input string (the S argument to wordsplit. */  
@@ -228,2 +238,8 @@ struct wordsplit
 
+/* Enable positional parameters */
+#define WRDSO_PARAMV         0x00004000
+/* Enable negative positional indices (${-1} is the last positional
+   parameter) */
+#define WRDSO_PARAM_NEGIDX   0x00008000
+
 #define WRDSO_BSKEEP          WRDSO_BSKEEP_WORD     
@@ -252,2 +268,3 @@ struct wordsplit
 #define WRDSE_USERERR    9
+#define WRDSE_BADPARAM  10
 
@@ -258,2 +275,3 @@ void wordsplit_free_words (wordsplit_t *ws);
 void wordsplit_free_envbuf (wordsplit_t *ws);
+void wordsplit_free_parambuf (struct wordsplit *ws);
 int wordsplit_get_words (wordsplit_t *ws, size_t *wordc, char ***wordv);
diff --git a/src/wordsplit.c b/src/wordsplit.c
index 521a1eb..6a33636 100644
--- a/src/wordsplit.c
+++ b/src/wordsplit.c
@@ -1,3 +1,3 @@
 /* wordsplit - a word splitter
-   Copyright (C) 2009-2018 Sergey Poznyakoff
+   Copyright (C) 2009-2019 Sergey Poznyakoff
 
@@ -29,2 +29,3 @@
 #include <glob.h>
+#include <limits.h>
 
@@ -58,2 +59,5 @@
 
+#define to_num(c) \
+  (ISDIGIT(c) ? c - '0' : (ISXDIGIT(c) ? toupper(c) - 'A' + 10 : 255 ))
+
 #define ALLOC_INIT 128
@@ -286,2 +290,10 @@ wordsplit_init (struct wordsplit *wsp, const char *input, size_t len,
     }
+
+  if (!(wsp->ws_options & WRDSO_PARAMV))
+    {
+      wsp->ws_paramv = NULL;
+      wsp->ws_paramc = 0;
+    }
+  wsp->ws_paramidx = wsp->ws_paramsiz = 0;
+  wsp->ws_parambuf = NULL;
   
@@ -1038,3 +1050,3 @@ static int
 wsplt_assign_var (struct wordsplit *wsp, const char *name, size_t namelen,
-                  char *value)
+                  char const *value)
 {
@@ -1073,3 +1085,3 @@ wsplt_assign_var (struct wordsplit *wsp, const char *name, size_t namelen,
                         free (newenv[j-1]);
-                      free (newenv[j-1]);
+                      free (newenv);
                       return _wsplt_nomem (wsp);
@@ -1144,2 +1156,66 @@ wsplt_assign_var (struct wordsplit *wsp, const char *name, size_t namelen,
 
+int
+wsplt_assign_param (struct wordsplit *wsp, int param_idx, char *value)
+{
+  char *v;
+  
+  if (param_idx < 0)
+    return WRDSE_BADPARAM;
+  if (param_idx == wsp->ws_paramc)
+    {
+      char **parambuf;
+      if (!wsp->ws_parambuf)
+        {
+          size_t i;
+          
+          parambuf = calloc ((size_t)param_idx + 1, sizeof (parambuf[0]));
+          if (!parambuf)
+            return _wsplt_nomem (wsp);
+
+          for (i = 0; i < wsp->ws_paramc; i++)
+            {
+              parambuf[i] = strdup (wsp->ws_paramv[i]);
+              if (!parambuf[i])
+                {
+                  for (; i > 1; i--)
+                    free (parambuf[i-1]);
+                  free (parambuf);
+                  return _wsplt_nomem (wsp);
+                }
+            }
+          
+          wsp->ws_parambuf = parambuf;
+          wsp->ws_paramidx = param_idx;
+          wsp->ws_paramsiz = param_idx + 1;
+        }
+      else
+        {
+          size_t n = wsp->ws_paramsiz;
+          
+          if ((size_t) -1 / 3 * 2 / sizeof (wsp->ws_parambuf[0]) <= n)
+            return _wsplt_nomem (wsp);
+          n += (n + 1) / 2;
+          parambuf = realloc (wsp->ws_parambuf, n * sizeof (wsp->ws_parambuf[0]));
+          if (!parambuf)
+            return _wsplt_nomem (wsp);
+          wsp->ws_parambuf = parambuf;
+          wsp->ws_paramsiz = n;
+          wsp->ws_parambuf[param_idx] = NULL;
+        }
+
+      wsp->ws_paramv = (const char**) wsp->ws_parambuf;
+      wsp->ws_paramc = param_idx + 1;
+    }
+  else if (param_idx > wsp->ws_paramc)
+    return WRDSE_BADPARAM;
+  
+  v = strdup (value);
+  if (!v)
+    return _wsplt_nomem (wsp);
+    
+  free (wsp->ws_parambuf[param_idx]);
+  wsp->ws_parambuf[param_idx] = v;
+  return WRDSE_OK;
+}
+
 /* Recover from what looked like a variable reference, but turned out
@@ -1179,2 +1255,4 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
   struct wordsplit ws;
+  int is_param = 0;
+  long param_idx = 0;
   
@@ -1187,3 +1265,3 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
     }
-  else if (ISDIGIT (str[0]))
+  else if ((wsp->ws_options & WRDSO_PARAMV) && ISDIGIT (str[0]))
     {
@@ -1191,4 +1269,27 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
       *pend = str;
+      is_param = 1;
+      param_idx = to_num (str[0]);
     }
-  else if (str[0] == '{' && (ISVARBEG (str[1]) || ISDIGIT (str[1])))
+  else if ((wsp->ws_options & WRDSO_PARAMV) && str[0] == '#')
+    {
+      char b[16];
+      snprintf (b, sizeof(b), "%d", (int) wsp->ws_paramc);
+      value = strdup (b);
+      if (!value)
+        return _wsplt_nomem (wsp);
+      if (wsnode_new (wsp, &newnode))
+        return 1;
+      wsnode_insert (wsp, newnode, *ptail, 0);
+      *ptail = newnode;
+      newnode->flags = _WSNF_WORD | _WSNF_NOEXPAND | flg;
+      newnode->v.word = value;
+      return 0;
+    }
+  else if (str[0] == '{'
+           && (ISVARBEG (str[1])
+               || (is_param = (((wsp->ws_options & WRDSO_PARAMV)
+                                && ISDIGIT (str[1]))
+                               || ((wsp->ws_options & WRDSO_PARAM_NEGIDX)
+                                   && (str[1] == '-'
+                                       && ISDIGIT (str[2]))))) != 0))
     {
@@ -1196,3 +1297,3 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
       len--;
-      for (i = 1; i < len; i++)
+      for (i = str[0] == '-' ? 1 : 0; i < len; i++)
         {
@@ -1224,5 +1325,12 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
             }
-          else if (ISDIGIT (str[1]))
+          else if (is_param)
             {
-              if (!ISDIGIT (str[i]))
+              if (ISDIGIT (str[i]))
+                {
+                  param_idx = param_idx * 10 + to_num (str[i]);
+                  if ((str[0] == '-' && -param_idx < INT_MIN)
+                      || param_idx > INT_MAX)
+                    return expvar_recover (wsp, str - 1, ptail, pend, flg);
+                }
+              else
                 {
@@ -1236,2 +1344,6 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
         }
+      
+      if (is_param && str[0] == '-')
+        param_idx = wsp->ws_paramc - param_idx;
+      
       if (i == len)
@@ -1256,10 +1368,11 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
     {
-      rc = wordsplit_find_env (wsp, str, i, &vptr);
-      if (rc == WRDSE_OK)
+      if (is_param)
         {
-          if (vptr)
+          if (param_idx >= 0 && param_idx < wsp->ws_paramc)
             {
-              value = strdup (vptr);
+              value = strdup (wsp->ws_paramv[param_idx]);
               if (!value)
                 rc = WRDSE_NOSPACE;
+              else
+                rc = WRDSE_OK;
             }
@@ -1268,7 +1381,22 @@ expvar (struct wordsplit *wsp, const char *str, size_t len,
         }
-      else if (wsp->ws_flags & WRDSF_GETVAR)
-        rc = wsp->ws_getvar (&value, str, i, wsp->ws_closure);
       else
-        rc = WRDSE_UNDEF;
+        {