Mac OS X: provide alternate implementation of posix_fallocate.

[libguestfs.git] / fish / alloc.c

diff --git a/fish/alloc.c b/fish/alloc.c
index fd5be2c..28c990f 100644 (file)
--- a/fish/alloc.c
+++ b/fish/alloc.c
@@ -54,12 +54,31 @@ do_alloc (const char *cmd, int argc, char *argv[])
     return -1;
   }
 
+#ifdef HAVE_POSIX_FALLOCATE
   if (posix_fallocate (fd, 0, size) == -1) {
     perror ("fallocate");
     close (fd);
     unlink (argv[0]);
     return -1;
   }
+#else
+  /* Slow emulation of posix_fallocate on platforms which don't have it. */
+  char buffer[BUFSIZ];
+  memset (buffer, 0, sizeof buffer);
+
+  size_t remaining = size;
+  while (remaining > 0) {
+    size_t n = remaining > sizeof buffer ? sizeof buffer : remaining;
+    ssize_t r = write (fd, buffer, n);
+    if (r == -1) {
+      perror ("write");
+      close (fd);
+      unlink (argv[0]);
+      return -1;
+    }
+    remaining -= r;
+  }
+#endif
 
   if (close (fd) == -1) {
     perror (argv[0]);
@@ -140,12 +159,12 @@ parse_size (const char *str, off_t *size_rtn)
    */
   if (sscanf (str, "%"SCNu64"%c", &size, &type) == 2) {
     switch (type) {
-    case 'k': case 'K': size *= 1024L; break;
-    case 'm': case 'M': size *= 1024L * 1024; break;
-    case 'g': case 'G': size *= 1024L * 1024 * 1024; break;
-    case 't': case 'T': size *= 1024L * 1024 * 1024 * 1024; break;
-    case 'p': case 'P': size *= 1024L * 1024 * 1024 * 1024 * 1024; break;
-    case 'e': case 'E': size *= 1024L * 1024 * 1024 * 1024 * 1024 * 1024; break;
+    case 'k': case 'K': size *= 1024ULL; break;
+    case 'm': case 'M': size *= 1024ULL * 1024ULL; break;
+    case 'g': case 'G': size *= 1024ULL * 1024ULL * 1024ULL; break;
+    case 't': case 'T': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
+    case 'p': case 'P': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
+    case 'e': case 'E': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
     case 's': size *= 512; break;
     default:
       fprintf (stderr, _("could not parse size specification '%s'\n"), str);
@@ -153,7 +172,7 @@ parse_size (const char *str, off_t *size_rtn)
     }
   }
   else if (sscanf (str, "%"SCNu64, &size) == 1)
-    size *= 1024;
+    size *= 1024ULL;
   else {
     fprintf (stderr, _("could not parse size specification '%s'\n"), str);
     return -1;