From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 28 Feb 2026 00:17:27 +0000 (-0800)
Subject: id: avoid unnecessary buffer flushing
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d41e1375cb38f49fad5dfcab0460b2e702964d56;p=thirdparty%2Fcoreutils.git

id: avoid unnecessary buffer flushing

* src/groups.c (main):
* src/id.c (main, print_stuff):
Don’t flush stdout before testing for write error.
Do the test only when in a loop, as a one-shot will
test for write error soon anyway.
---

diff --git a/NEWS b/NEWS
index 473b7c21d8..7d46a5bcef 100644
--- a/NEWS
+++ b/NEWS
@@ -22,7 +22,7 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** Improvements
 
-  'groups' and 'id' will now exit immediately upon receiving a write error,
+  'groups' and 'id' will now exit sooner after a write error,
   which is significant when listing information for many users.
 
   'nl' now supports multi-byte --section-delimiter characters.
diff --git a/src/groups.c b/src/groups.c
index 3daf410d9f..57acd376bc 100644
--- a/src/groups.c
+++ b/src/groups.c
@@ -135,7 +135,7 @@ main (int argc, char **argv)
             ok = false;
           putchar ('\n');
 
-          if (fflush (stdout) < 0)
+          if (ferror (stdout))
             write_error ();
         }
     }
diff --git a/src/id.c b/src/id.c
index 02c3bf9b50..27b3e8b708 100644
--- a/src/id.c
+++ b/src/id.c
@@ -277,6 +277,8 @@ main (int argc, char **argv)
               ruid = euid = pwd->pw_uid;
               rgid = egid = pwd->pw_gid;
               print_stuff (pw_name);
+              if (ferror (stdout))
+                write_error ();
             }
           free (pw_name);
         }
@@ -458,7 +460,4 @@ print_stuff (char const *pw_name)
     {
       putchar (opt_zero ? '\0' : '\n');
     }
-
-  if (fflush (stdout) < 0)
-    write_error ();
 }