SIGPIPE recommendation

[Bruno Haible]

Processes that write to subprocesses through pipes usually need to ignore
SIGPIPE while doing so. I'm adding a reminder comment.


2008-09-28  Bruno Haible  <address@hidden>

        * lib/pipe.h (create_pipe_out, create_pipe_bidi): Add comment about
        SIGPIPE.

--- lib/pipe.h.orig     2008-09-28 16:05:57.000000000 +0200
+++ lib/pipe.h  2008-09-28 16:02:47.000000000 +0200
@@ -1,5 +1,5 @@
 /* Creation of subprocesses, communicating via pipes.
-   Copyright (C) 2001-2003, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2001-2003, 2006, 2008 Free Software Foundation, Inc.
    Written by Bruno Haible <address@hidden>, 2001.
 
    This program is free software: you can redistribute it and/or modify
@@ -78,6 +78,8 @@
  *           write       system                read
  *    parent  ->   fd[0]   ->   STDIN_FILENO    ->   child
  *
+ * Note: When writing to a child process, it is useful to ignore the SIGPIPE
+ * signal and the EPIPE error code.
  */
 extern pid_t create_pipe_out (const char *progname,
                              const char *prog_path, char **prog_argv,
@@ -105,6 +107,8 @@
  *    parent  <-   fd[0]   <-   STDOUT_FILENO   <-   child
  *           read        system                write
  *
+ * Note: When writing to a child process, it is useful to ignore the SIGPIPE
+ * signal and the EPIPE error code.
  */
 extern pid_t create_pipe_bidi (const char *progname,
                               const char *prog_path, char **prog_argv,