[PATCH] splice-in: accept block device as input

diff --git a/splice-in.c b/splice-in.c
index 14b31f198619deec2ec031eb634cbedc4cf2e258..3c01cc367e9f9ac3616bbafd24e4ef440e96129f 100644 (file)
--- a/splice-in.c
+++ b/splice-in.c
@@ -7,18 +7,40 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 
 #include "splice.h"
 
+#ifndef BLKGETSIZE64
+#define BLKGETSIZE64   _IOR(0x12,114,size_t)
+#endif
+
 static int usage(char *name)
 {
        fprintf(stderr, "%s: infile | ...\n", name);
        return 1;
 }
 
-int main(int argc, char *argv[])
+static long long in_size(int fd)
 {
+       unsigned long long bytes;
        struct stat sb;
+
+       if (fstat(fd, &sb) < 0)
+               return error("fstat");
+
+       if (sb.st_size)
+               return sb.st_size;
+
+       if (ioctl(fd, BLKGETSIZE64, &bytes) < 0)
+               return error("BLKGETSIZE64");
+
+       return bytes;
+}
+
+int main(int argc, char *argv[])
+{
+       long long isize;
        int fd;
 
        if (argc < 2)
@@ -31,19 +53,20 @@ int main(int argc, char *argv[])
        if (fd < 0)
                return error("open input");
 
-       if (fstat(fd, &sb) < 0)
-               return error("stat input");
+       isize = in_size(fd);
+       if (isize < 0)
+               return isize;
 
-       do {
-               int ret = splice(fd, NULL, STDOUT_FILENO, NULL, sb.st_size, 0);
+       while (isize) {
+               int ret = splice(fd, NULL, STDOUT_FILENO, NULL, isize, 0);
 
                if (ret < 0)
                        return error("splice");
                else if (!ret)
                        break;
 
-               sb.st_size -= ret;
-       } while (1);
+               isize -= ret;
+       }
 
        close(fd);
        return 0;