Chapter 4

chp4/readv.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+int main(void) {
+    char foo[48], bar[51], baz[49];
+    int fd = open("buccaneer.txt", O_RDONLY);
+    if (fd == -1) {
+        perror("open");
+        return 1;
+    }
+
+    // setup our iovec structures
+    struct iovec iov[3];
+    iov[0].iov_base = foo;
+    iov[0].iov_len = sizeof(foo);
+    iov[1].iov_base = bar;
+    iov[1].iov_len = sizeof(bar);
+    iov[2].iov_base = baz;
+    iov[2].iov_len = sizeof(baz);
+
+    // read into the structures with a single call
+    int nr = readv(fd, iov, 3);
+    if (nr == -1) {
+        perror("readv");
+        return 1;
+    }
+
+    for (int i = 0; i < 3; i++)
+        printf("%d: %s", i, (char *)iov[i].iov_base);
+
+    if (close(fd)) {
+        perror("close");
+        return 1;
+    }
+
+    return 0;
+}