X-Git-Url: https://git.sesse.net/?p=plocate;a=blobdiff_plain;f=complete_pread.cpp;h=3b369455f920304958d9fb3dee0bf08ffc43cc0b;hp=49136747b94fb680a8fe4285771f75c6a98e018a;hb=HEAD;hpb=acce03bb32917e21f2d1d49c5a460d3cd2f72a11

diff --git a/complete_pread.cpp b/complete_pread.cpp
index 4913674..3b36945 100644
--- a/complete_pread.cpp
+++ b/complete_pread.cpp
@@ -3,7 +3,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
-void complete_pread(int fd, void *ptr, size_t len, off_t offset)
+bool try_complete_pread(int fd, void *ptr, size_t len, off_t offset)
 {
 	while (len > 0) {
 		ssize_t ret = pread(fd, ptr, len, offset);
@@ -11,11 +11,23 @@ void complete_pread(int fd, void *ptr, size_t len, off_t offset)
 			continue;
 		}
 		if (ret <= 0) {
-			perror("pread");
-			exit(1);
+			return false;
 		}
 		ptr = reinterpret_cast<char *>(ptr) + ret;
 		len -= ret;
-		offset -= ret;
+		offset += ret;
+	}
+	return true;
+}
+
+void complete_pread(int fd, void *ptr, size_t len, off_t offset)
+{
+	if (!try_complete_pread(fd, ptr, len, offset)) {
+		if (errno == 0) {
+			fprintf(stderr, "pread: Short read (file corrupted?)\n");
+		} else {
+			perror("pread");
+		}
+		exit(1);
 	}
 }