[shepherd] 02/05: shepherd: Open log file as O_CLOEXEC.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository shepherd.

commit fc7735f6a74e9f2bb07fdeed89f3aedd04d8ef4b
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Mon Aug 29 17:04:05 2022 +0200

    shepherd: Open log file as O_CLOEXEC.
    
    * modules/shepherd/support.scm (buffering): New procedure.
    * modules/shepherd.scm (main): Define 'log-flags'.  Open log file with
    'open' and LOG-FLAGS.
---
 modules/shepherd.scm         | 10 ++++++++--
 modules/shepherd/support.scm |  6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/modules/shepherd.scm b/modules/shepherd.scm
index 9fbed1b..860fd30 100644
--- a/modules/shepherd.scm
+++ b/modules/shepherd.scm
@@ -253,6 +253,10 @@ already ~a threads running, disabling 'signalfd' support")
     ;; the signal thread.
     (maybe-signal-port %precious-signals))
 
+  (define log-flags
+    ;; Flags for 'open' when opening the log file.
+    (logior O_CREAT O_APPEND O_WRONLY O_CLOEXEC))
+
   (initialize-cli)
 
   (let ((config-file #f)
@@ -335,11 +339,13 @@ already ~a threads running, disabling 'signalfd' support")
     ;; Enable logging as first action.
     (parameterize ((log-output-port
                     (cond (logfile
-                           (open-file logfile "al"))
+                           (buffering (open logfile log-flags)
+                                      'line))
                           ((zero? (getuid))
                            (syslog-output-port))
                           (else
-                           (open-file (user-default-log-file) "al"))))
+                           (buffering (open (user-default-log-file) log-flags)
+                                      'line))))
                    (%current-logfile-date-format
                     (if (and (not logfile) (zero? (getuid)))
                         (format #f "shepherd[~d]: " (getpid))
diff --git a/modules/shepherd/support.scm b/modules/shepherd/support.scm
index a1f9d75..36be3ff 100644
--- a/modules/shepherd/support.scm
+++ b/modules/shepherd/support.scm
@@ -28,6 +28,7 @@
             assert
             label
 
+            buffering
             catch-system-error
             with-system-error-handling
             with-atomic-file-output
@@ -94,6 +95,11 @@
     (letrec ((NAME PROC))
       (apply NAME args))))
 
+(define (buffering port type . args)
+  "Return PORT after changing its buffering to TYPE and ARGS."
+  (apply setvbuf port type args)
+  port)
+
 ;; Evaluate `EXPR ...' until a system error occurs, then skip the
 ;; remaining code.
 (define-syntax-rule (catch-system-error EXPR ...)