[PATCH] vmsplice: add clear option (-c)

diff --git a/vmsplice.c b/vmsplice.c
index 9cad246218792dce1247a0c6d1ec90d7d8ededbf..74780e51b72d3ce132db1e80bd1c2609b23a3bc0 100644 (file)
--- a/vmsplice.c
+++ b/vmsplice.c
@@ -7,6 +7,8 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <string.h>
+#include <getopt.h>
 #include <sys/poll.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -23,6 +25,8 @@
 #define ALIGN(buf)     (buf)
 #endif
 
+static int do_clear;
+
 int do_vmsplice(int fd, void *buffer, int len)
 {
        struct pollfd pfd = { .fd = fd, .events = POLLOUT, };
@@ -49,6 +53,30 @@ int do_vmsplice(int fd, void *buffer, int len)
        return 0;
 }
 
+static int usage(char *name)
+{
+       fprintf(stderr, "%s: [-c]\n", name);
+       return 1;
+}
+
+static int parse_options(int argc, char *argv[])
+{
+       int c, index = 1;
+
+       while ((c = getopt(argc, argv, "m")) != -1) {
+               switch (c) {
+               case 'c':
+                       do_clear = 1;
+                       index++;
+                       break;
+               default:
+                       return -1;
+               }
+       }
+
+       return index;
+}
+
 int main(int argc, char *argv[])
 {
        unsigned char *buffer;
@@ -56,6 +84,9 @@ int main(int argc, char *argv[])
        long page_size;
        int i, ret;
 
+       if (parse_options(argc, argv) < 0)
+               return usage(argv[0]);
+
        if (fstat(STDOUT_FILENO, &sb) < 0)
                return error("stat");
        if (!S_ISFIFO(sb.st_mode)) {
@@ -100,6 +131,14 @@ int main(int argc, char *argv[])
                 * the buffer, but we do now know that all parts of the first
                 * half have been consumed from the pipe - so we can reuse that.
                 */
+
+               /*
+                * Test option - clear the first half of the buffer, should
+                * be safe now
+                */
+               if (do_clear)
+                       memset(buffer, 0x00, SPLICE_SIZE);
+                       
        } while (0);
 
        return 0;