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--- os_cp:fork_exec_pipes [2025/05/19 20:27] – jkonczak
+++ os_cp:fork_exec_pipes [2026/05/20 18:31] (current) – jkonczak
@@ Line 20: / Line 20: @@
 There is a list of things that ''fork'' does not clone or that are reset for the
-child process upon ''fork''. See POSIX standard or Linux manual on fork for details.
+child process upon ''fork''.
+\\ See POSIX standard or
+[[https://man7.org/linux/man-pages/man2/fork.2.html|Linux manual on fork]]
+for details.
+\\
 Notice that:
   * all stack and heap memory is copied
@@ Line 160: / Line 164: @@
 <html><div style="margin-bottom:-1.4em"></div></html>
 <code c>
-char arg0[] = "ls";     char arg2[] = "-a";
-char arg1[] = "-l";     char arg3[] = "/tmp";
-char *argv[] = {arg0, arg1, arg2, arg3, NULL};
 # Argument list:
-execlp("ls",    arg0, arg1, arg2, arg3, NULL);
+execlp("ls",           "ls", "-l", "-a", "/tmp", NULL);
-# Argument vector:
+#  Argument vector:
+char        *argv[] = {"ls", "-l", "-a", "/tmp", NULL};
 execvp("ls", argv);
 </code>
@@ Line 233: / Line 236: @@
     double elapsedSec = (end.tv_sec - start.tv_sec) + (end.tv_nsec - start.tv_nsec) / 1e9;
 </code>
+<HTML></div><div style="margin-top:-1.4em"></HTML>
+Instead of the C11 function ''[[https://en.cppreference.com/c/chrono/timespec_get|timespec_get]](&//x//, TIME_UTC);'', you may also
+use the POSIX function ''[[https://pubs.opengroup.org/onlinepubs/9799919799/functions/clock_gettime.html|clock_gettime]](CLOCK_MONOTONIC, &//x//);''.
 <HTML></div></HTML>
 </small>
@@ Line 387: / Line 393: @@
 <small>Pipe is unidirectional. The unix //socket// is its bidirectional
 equivalent. See ''[[https://man7.org/linux/man-pages/man7/unix.7.html|man 7 unix]]''
-for details.</small>
+for details.
+\\
+POSIX standard also defines (but not mandates)
+[[https://man7.org/linux/man-pages/man7/mq_overview.7.html|message queues]].
+</small>
 ~~Exercise.#~~ Write a program that: