Merged revisions 182278 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

........
  r182278 | tilghman | 2009-03-16 12:33:38 -0500 (Mon, 16 Mar 2009) | 7 lines
  
  Fix an off-by-one error in the FILE() function, and extend FILE()'s length parameter to work like variable substitution.
  Previously, FILE() returned one less character than specified, due to the
  terminating NULL.  Both the offset and length parameters now behave
  identically to the way variable substitution offsets and lengths also work.
  (closes issue #14670)
   Reported by: BMC
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@182279 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_env.c

@@ -113,40 +113,59 @@ static int file_read(struct ast_channel *chan, const char *cmd, char *data, char
 		AST_APP_ARG(offset);
 		AST_APP_ARG(length);
 	);
-	int offset = 0, length;
+	int offset = 0, length, res = 0;
 	char *contents;
+	size_t contents_len;
 
 	AST_STANDARD_APP_ARGS(args, data);
-	if (args.argc > 1)
+	if (args.argc > 1) {
 		offset = atoi(args.offset);
+	}
 
 	if (args.argc > 2) {
-		if ((length = atoi(args.length)) < 1) {
-			ast_log(LOG_WARNING, "Invalid length '%s'.  Returning the max (%d)\n", args.length, (int)len);
-			length = len;
-		} else if (length > len) {
-			ast_log(LOG_WARNING, "Length %d is greater than the max (%d).  Truncating output.\n", length, (int)len);
+		/* The +1/-1 in this code section is to accomodate for the terminating NULL. */
+		if ((length = atoi(args.length) + 1) > len) {
+			ast_log(LOG_WARNING, "Length %d is greater than the max (%d).  Truncating output.\n", length - 1, (int)len - 1);
 			length = len;
 		}
-	} else
+	} else {
 		length = len;
+	}
 
-	if (!(contents = ast_read_textfile(args.filename)))
+	if (!(contents = ast_read_textfile(args.filename))) {
 		return -1;
+	}
 
-	if (offset >= 0)
-		ast_copy_string(buf, &contents[offset], length);
-	else {
-		size_t tmp = strlen(contents);
-		if (offset * -1 > tmp) {
-			ast_log(LOG_WARNING, "Offset is larger than the file size.\n");
-			offset = tmp * -1;
+	do {
+		contents_len = strlen(contents);
+		if (offset > contents_len) {
+			res = -1;
+			break;
 		}
-		ast_copy_string(buf, &contents[tmp + offset], length);
-	}
+
+		if (offset >= 0) {
+			if (length < 0) {
+				if (contents_len - offset + length < 0) {
+					/* Nothing left after trimming */
+					res = -1;
+					break;
+				}
+				ast_copy_string(buf, &contents[offset], contents_len + length);
+			} else {
+				ast_copy_string(buf, &contents[offset], length);
+			}
+		} else {
+			if (offset * -1 > contents_len) {
+				ast_log(LOG_WARNING, "Offset is larger than the file size.\n");
+				offset = contents_len * -1;
+			}
+			ast_copy_string(buf, &contents[contents_len + offset], length);
+		}
+	} while (0);
+
 	ast_free(contents);
 
-	return 0;
+	return res;
 }
 
 static struct ast_custom_function env_function = {