libc: Make fread() and fwrite() less awkward

apps/src/init.c

@@ -21,7 +21,7 @@ void show_motd()
     }
 
     char buf[4096];
-    size_t nread = fread(buf, sizeof(buf) - 1, 1, fp);
+    size_t nread = fread(buf, 1, sizeof(buf) - 1, fp);
     if (ferror(fp))
     {
         perror("fread");

libs/libc/src/file.cpp

@@ -127,15 +127,15 @@ extern "C"
 
     size_t fread(void* buf, size_t size, size_t nmemb, FILE* stream)
     {
-        ssize_t status =
-            read(stream->f_fd, buf,
-                 size * nmemb); // FIXME: This function should use file_read_buf() to not conflict with fgets().
+        size_t rsize = size * nmemb;
+        ssize_t status = read(stream->f_fd, buf, rsize);
         if (status < 0)
         {
             stream->f_err = 1;
             return 0;
         }
-        if (status == 0) stream->f_eof = 1;
+        if (status == 0 && rsize) stream->f_eof = 1;
+        if (status == 0) return (size_t)status;
         return (size_t)status / size;
     }
 
@@ -281,13 +281,15 @@ extern "C"
 
     size_t fwrite(const void* buf, size_t size, size_t nmemb, FILE* stream)
     {
-        ssize_t status = write(stream->f_fd, buf, size * nmemb);
+        size_t rsize = size * nmemb;
+        ssize_t status = write(stream->f_fd, buf, rsize);
         if (status < 0)
         {
             stream->f_err = 1;
             return 0;
         }
-        if (status == 0) stream->f_eof = 1;
+        if (status == 0 && rsize) stream->f_eof = 1;
+        if (status == 0) return (size_t)status;
         return (size_t)status / size;
     }