Bug #35753: check the success/failure of material I/O operations.

* lib/listfile.c (list_file): Check the result of fprintf to
determine if there was an I/O error on output.  Return false (bool
instead of void) if so.
(print_name_without_quoting): Likewise.
(print_name_with_quoting): Likewise.
(print_name): Propagate the result of print_name_without_quoting
or print_name_with_quoting (and make all three functions return bool).
* find/pred.c (is_ok): Check the result of fprintf to
determine if there was an I/O error on output.  Exit fatally if
there was a problem (since we cannot expect the user to say "yes"
or "no" to a prompt they will not have seen).
* xargs/xargs.c (print_args): Check the result of fprintf and
fflush to determine if there was an I/O error on output.  Exit
fatally for the same reason as above if there is a problem.
* NEWS: Mention this bugfix (now that it is fully fixed).

1 files changed, 10 insertions, 2 deletions

diff --git a/xargs/xargs.c b/xargs/xargs.c
index 17c68bbd..89e78a3a 100644
--- a/xargs/xargs.c
+++ b/xargs/xargs.c
@@ -1051,7 +1051,11 @@ print_args (bool ask)
   size_t i;
 
   for (i = 0; i < bc_state.cmd_argc - 1; i++)
-    fprintf (stderr, "%s ", bc_state.cmd_argv[i]);
+    {
+      if (fprintf (stderr, "%s ", bc_state.cmd_argv[i]) < 0)
+	error (EXIT_FAILURE, errno, _("Failed to write to stderr"));
+    }
+
   if (ask)
     {
       static FILE *tty_stream;
@@ -1065,10 +1069,14 @@ print_args (bool ask)
 		   _("failed to open /dev/tty for reading"));
 	}
       fputs ("?...", stderr);
-      fflush (stderr);
+      if (fflush (stderr) != 0)
+	error (EXIT_FAILURE, errno, _("Failed to write to stderr"));
+
       c = savec = getc (tty_stream);
       while (c != EOF && c != '\n')
 	c = getc (tty_stream);
+      if (EOF == c)
+	error (EXIT_FAILURE, errno, _("Failed to read from stdin"));
       if (savec == 'y' || savec == 'Y')
 	return true;
     }