splice: more examples...

[metze/misc/junkcode.git] / splice / readwrite2.c

diff --git a/splice/readwrite2.c b/splice/readwrite2.c
new file mode 100644 (file)
index 0000000..618683f
--- /dev/null
+++ b/splice/readwrite2.c
@@ -0,0 +1,55 @@
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/uio.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#include <sys/socket.h>
+#include <sys/sendfile.h>
+
+int main(int argc, const char * const *argv)
+{
+       int zfd = open("/dev/zero", O_RDONLY);
+       int nfd = open("/dev/null", O_WRONLY);
+       size_t total = 0;
+#define TOTAL 0xFFFFFFFFF
+#define BUFFER 0x100000
+       size_t i = 0;
+
+       while (total < TOTAL) {
+               uint8_t buf[BUFFER];
+               ssize_t zret;
+               ssize_t nret;
+
+               errno = 0;
+               zret = read(zfd, buf, sizeof(buf));
+               if (zret < 0) {
+                       printf("%d: zret[%lld] errno[%d/%s]\n", __LINE__,
+                               (long long int)zret, errno, strerror(errno));
+                       break;
+               }
+
+               errno = 0;
+               nret = write(nfd, buf, zret);
+               if (nret < 0) {
+                       printf("%d: nret[%lld] errno[%d/%s]\n", __LINE__,
+                               (long long int)nret, errno, strerror(errno));
+                       break;
+               }
+               if (nret != zret) {
+                       printf("%d: zret[%lld] nret[%lld]\n", __LINE__,
+                               (long long int)zret,
+                               (long long int)nret);
+                       break;
+               }
+
+               total += nret;
+               i++;
+       }
+
+       printf("i[%lld]\n", (long long int)i);
+       return 0;
+}