Implemented subst

diff --git a/variable.c b/variable.c
index ef98a445a9094a8cba3dd9d8231a677d7a60f9fa..b6f645f5d4696fe102c82568be3493dae2bdb1e8 100644 (file)
--- a/variable.c
+++ b/variable.c
@@ -50,6 +50,77 @@ static char *func_error (const char *filename, unsigned long line_no, char *inpu
 
 }
 
+static char *func_subst (const char *filename, unsigned long line_no, char *input) {
+
+    char *src, *dst, *new_body, *old_body, *p;
+    unsigned long size, pos, l, dst_len, src_len;
+    
+    (void) filename;
+    (void) line_no;
+    
+    src = input;
+    
+    if (!(dst = strstr (src, ",")) || !dst[0]) {
+        return 0;
+    }
+    
+    *dst++ = 0;
+    
+    if (!(old_body = strstr (dst, ",")) || !old_body[0]) {
+        return 0;
+    }
+    
+    *old_body++ = 0;
+    
+    size = 16 + strlen (old_body);
+    new_body = xmalloc (size);
+    
+    dst_len = strlen (dst);
+    src_len = strlen (src);
+    
+    pos = 0;
+    
+    while (*old_body) {
+    
+        if ((p = strstr (old_body, src))) {
+        
+            l = p - old_body;
+            
+            if (l + dst_len + 1 >= size - pos) {
+            
+                size += l + dst_len + 1 + strlen (old_body);
+                new_body = xrealloc (new_body, size);
+            
+            }
+            
+            memcpy (new_body + pos, old_body, l);
+            pos += l;
+            
+            memcpy (new_body + pos, dst, dst_len + 1);
+            pos += dst_len;
+            
+            old_body = p + src_len;
+        
+        } else {
+        
+            if (strlen (old_body) >= size - pos) {
+            
+                size += strlen (old_body) + size - pos + 1;
+                new_body = xrealloc (new_body, size);
+            
+            }
+            
+            memcpy (new_body + pos, old_body, strlen (old_body) + 1);
+            break;
+        
+        }
+    
+    }
+    
+    return new_body;
+
+}
+
 #if         defined (_WIN32) || defined (__WIN32__)
 # include       <windows.h>
 static char *internal_commands[] = {
@@ -462,6 +533,8 @@ static struct builtin_function builtin_functions[] ={
 #endif
     
     {   "eval",     &func_eval      },
+    {   "subst",    &func_subst     },
+    
     {   0,          0               }
 
 };