added --no-overwrite option to rrdtool create. It prevents rrdtool from clobbering...

[rrdtool-all.git] / program / src / rrd_create.c

diff --git a/program/src/rrd_create.c b/program/src/rrd_create.c
index 75c3722fe24b2680f9c6d4d03fedf4c106ea1628..4e98d53c40be069539ee45c19334f271362f631b 100644 (file)
--- a/program/src/rrd_create.c
+++ b/program/src/rrd_create.c
@@ -13,6 +13,7 @@
 #include "rrd_hw.h"
 
 #include "rrd_is_thread_safe.h"
+static int opt_no_overwrite = 0;
 
 #ifdef WIN32
 #include <fcntl.h>
@@ -42,6 +43,7 @@ int rrd_create(
     struct option long_options[] = {
         {"start", required_argument, 0, 'b'},
         {"step", required_argument, 0, 's'},
+        {"no-overwrite", no_argument, 0, 'O'},
         {0, 0, 0, 0}
     };
     int       option_index = 0;
@@ -57,7 +59,7 @@ int rrd_create(
     opterr = 0;         /* initialize getopt */
 
     while (1) {
-        opt = getopt_long(argc, argv, "b:s:", long_options, &option_index);
+        opt = getopt_long(argc, argv, "Ob:s:", long_options, &option_index);
 
         if (opt == EOF)
             break;
@@ -93,6 +95,10 @@ int rrd_create(
             pdp_step = long_tmp;
             break;
 
+        case 'O':
+            opt_no_overwrite = 1;
+           break;
+
         case '?':
             if (optopt != 0)
                 rrd_set_error("unknown option '%c'", optopt);
@@ -687,6 +693,11 @@ int rrd_create_fn(
     flags |= O_BINARY;
 #endif
 
+    /* with O_CREAT (above) causes open to fail with EEXIST when if exists */
+    if (opt_no_overwrite) {
+      flags |= O_EXCL;
+    }
+
     if ((rrd_file = open(file_name, flags, 0666)) < 0) {
         rrd_set_error("creating '%s': %s", file_name, rrd_strerror(errno));
         rrd_free2(rrd);