From c279fd10970acf374eb939c2e4e15241eecd7f13 Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@serenityos.org>
Date: Wed, 12 Oct 2022 14:46:15 +0100
Subject: [PATCH] cksum: Manually count file size instead of using stat()

`stat()` doesn't work for stdin, but this does.
---
 Userland/Utilities/cksum.cpp | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/Userland/Utilities/cksum.cpp b/Userland/Utilities/cksum.cpp
index 62f2c5c71f..31a57e3d50 100644
--- a/Userland/Utilities/cksum.cpp
+++ b/Userland/Utilities/cksum.cpp
@@ -54,14 +54,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
             continue;
         }
         auto file = file_or_error.release_value();
-
-        auto stat_or_error = Core::System::stat(filepath);
-        if (stat_or_error.is_error()) {
-            warnln("{}: Failed to fstat {}: {}", arguments.strings[0], filepath, stat_or_error.error());
-            fail = true;
-            continue;
-        }
-        auto st = stat_or_error.release_value();
+        size_t file_size = 0;
 
         if (algorithm == "crc32") {
             Crypto::Checksum::CRC32 crc32;
@@ -72,9 +65,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
                     fail = true;
                     continue;
                 }
+                file_size += data_or_error.value().size();
                 crc32.update(data_or_error.value());
             }
-            outln("{:08x} {} {}", crc32.digest(), st.st_size, path);
+            outln("{:08x} {} {}", crc32.digest(), file_size, path);
         } else if (algorithm == "adler32") {
             Crypto::Checksum::Adler32 adler32;
             while (!file->is_eof()) {
@@ -84,9 +78,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
                     fail = true;
                     continue;
                 }
+                file_size += data_or_error.value().size();
                 adler32.update(data_or_error.value());
             }
-            outln("{:08x} {} {}", adler32.digest(), st.st_size, path);
+            outln("{:08x} {} {}", adler32.digest(), file_size, path);
         } else {
             warnln("{}: Unknown checksum algorithm: {}", arguments.strings[0], algorithm);
             exit(1);