sigaction既可以是结构又可以是函数吗？

我注意到sigaction被定义为struct和function(http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html)：

    int sigaction(int, const struct sigaction *restrict,
       struct sigaction *restrict);

使用它的一个例子是：

    struct sigaction sa;

    /* Set up handler */
    sa.sa_flags = SA_SIGINFO|SA_RESTART;
    sa.sa_sigaction = timer_expiry;

    /* Setup signal watchdog */
    if (sigaction(SIG_WDOG, &sa, NULL) == -1) {
       printf("ERROR: Failed to set wdog signal with %s",
           strerror(errno));
    }

解决方法:

C有几个标识符的名称空间;函数标识符和结构标记标识符位于不同的名称空间中.

(C11, 6.2.3 Name spaces of identifiers p1) “If more than one declaration of a particular identifier is visible at any point in a
translation unit, the syntactic context disambiguates uses that refer to different entities.
Thus, there are separate name spaces for various categories of identifiers, as follows:

• label names (disambiguated by the syntax of the label declaration and use);

• the tags of structures, unions, and enumerations (disambiguated by following any32) of the keywords struct, union, or enum);

• the members of structures or unions; each structure or union has a separate
  name space for its members (disambiguated by the type of the
  expression used to access the member via the . or -> operator);

• all other identifiers, called ordinary identifiers (declared in ordinary declarators or as enumeration constants)

.

标签：unix,c-3,linux,sigaction
来源： https://codeday.me/bug/20190609/1205149.html