{"id":5601,"date":"2022-12-20T18:45:35","date_gmt":"2022-12-20T21:45:35","guid":{"rendered":"http:\/\/lode.uno\/linux-man\/index.php\/2022\/12\/20\/getsockopt-man3p\/"},"modified":"2022-12-20T18:45:35","modified_gmt":"2022-12-20T21:45:35","slug":"getsockopt-man3p","status":"publish","type":"post","link":"https:\/\/lode.uno\/linux-man\/2022\/12\/20\/getsockopt-man3p\/","title":{"rendered":"GETSOCKOPT (man3p)"},"content":{"rendered":"<h1 align=\"center\">GETSOCKOPT<\/h1>\n<p> <a href=\"#PROLOG\">PROLOG<\/a><br \/> <a href=\"#NAME\">NAME<\/a><br \/> <a href=\"#SYNOPSIS\">SYNOPSIS<\/a><br \/> <a href=\"#DESCRIPTION\">DESCRIPTION<\/a><br \/> <a href=\"#RETURN VALUE\">RETURN VALUE<\/a><br \/> <a href=\"#ERRORS\">ERRORS<\/a><br \/> <a href=\"#EXAMPLES\">EXAMPLES<\/a><br \/> <a href=\"#APPLICATION USAGE\">APPLICATION USAGE<\/a><br \/> <a href=\"#RATIONALE\">RATIONALE<\/a><br \/> <a href=\"#FUTURE DIRECTIONS\">FUTURE DIRECTIONS<\/a><br \/> <a href=\"#SEE ALSO\">SEE ALSO<\/a><br \/> <a href=\"#COPYRIGHT\">COPYRIGHT<\/a> <\/p>\n<hr>\n<h2>PROLOG <a name=\"PROLOG\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">This manual page is part of the POSIX Programmer\u2019s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.<\/p>\n<h2>NAME <a name=\"NAME\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">getsockopt \u2014 get the socket options<\/p>\n<h2>SYNOPSIS <a name=\"SYNOPSIS\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">#include <sys\/socket.h><\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">int getsockopt(int <i>socket<\/i>, int <i>level<\/i>, int <i>option_name,<\/i> <br \/> void *restrict <i>option_value<\/i>, socklen_t *restrict <i>option_len<\/i>);<\/p>\n<h2>DESCRIPTION <a name=\"DESCRIPTION\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>getsockopt<\/i>() function manipulates options associated with a socket.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>getsockopt<\/i>() function shall retrieve the value for the option specified by the <i>option_name<\/i> argument for the socket specified by the <i>socket<\/i> argument. If the size of the option value is greater than <i>option_len<\/i>, the value stored in the object pointed to by the <i>option_value<\/i> argument shall be silently truncated. Otherwise, the object pointed to by the <i>option_len<\/i> argument shall be modified to indicate the actual length of the value.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>level<\/i> argument specifies the protocol level at which the option resides. To retrieve options at the socket level, specify the <i>level<\/i> argument as SOL_SOCKET. To retrieve options at other levels, supply the appropriate level identifier for the protocol controlling the option. For example, to indicate that an option is interpreted by the TCP (Transmission Control Protocol), set <i>level<\/i> to IPPROTO_TCP as defined in the <i><netinet\/in.h><\/i> header.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The socket in use may require the process to have appropriate privileges to use the <i>getsockopt<\/i>() function.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>option_name<\/i> argument specifies a single option to be retrieved. It can be one of the socket-level options defined in <b><sys_socket.h><\/b> and described in <i>Section 2.10.16<\/i>, <i>Use of Options<\/i>.<\/p>\n<h2>RETURN VALUE <a name=\"RETURN VALUE\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">Upon successful completion, <i>getsockopt<\/i>() shall return 0; otherwise, \u22121 shall be returned and <i>errno<\/i> set to indicate the error.<\/p>\n<h2>ERRORS <a name=\"ERRORS\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>getsockopt<\/i>() function shall fail if:<\/p>\n<table width=\"100%\" border=\"0\" rules=\"none\" frame=\"void\" cellspacing=\"0\" cellpadding=\"0\">\n<tr valign=\"top\" align=\"left\">\n<td width=\"11%\"><\/td>\n<td width=\"9%\">\n<p><b>EBADF<\/b><\/p>\n<\/td>\n<td width=\"2%\"><\/td>\n<td width=\"78%\">\n<p>The <i>socket<\/i> argument is not a valid file descriptor.<\/p>\n<\/td>\n<\/tr>\n<tr valign=\"top\" align=\"left\">\n<td width=\"11%\"><\/td>\n<td width=\"9%\">\n<p><b>EINVAL<\/b><\/p>\n<\/td>\n<td width=\"2%\"><\/td>\n<td width=\"78%\">\n<p>The specified option is invalid at the specified socket level.<\/p>\n<\/td>\n<\/tr>\n<\/table>\n<p style=\"margin-left:11%;\"><b>ENOPROTOOPT<\/b><\/p>\n<p style=\"margin-left:22%;\">The option is not supported by the protocol.<\/p>\n<p style=\"margin-left:11%;\"><b>ENOTSOCK<\/b><\/p>\n<p style=\"margin-left:22%;\">The <i>socket<\/i> argument does not refer to a socket.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The <i>getsockopt<\/i>() function may fail if:<\/p>\n<table width=\"100%\" border=\"0\" rules=\"none\" frame=\"void\" cellspacing=\"0\" cellpadding=\"0\">\n<tr valign=\"top\" align=\"left\">\n<td width=\"11%\"><\/td>\n<td width=\"9%\">\n<p><b>EACCES<\/b><\/p>\n<\/td>\n<td width=\"2%\"><\/td>\n<td width=\"78%\">\n<p>The calling process does not have appropriate privileges.<\/p>\n<\/td>\n<\/tr>\n<tr valign=\"top\" align=\"left\">\n<td width=\"11%\"><\/td>\n<td width=\"9%\">\n<p><b>EINVAL<\/b><\/p>\n<\/td>\n<td width=\"2%\"><\/td>\n<td width=\"78%\">\n<p>The socket has been shut down.<\/p>\n<\/td>\n<\/tr>\n<\/table>\n<p style=\"margin-left:11%;\"><b>ENOBUFS<\/b><\/p>\n<p style=\"margin-left:22%;\">Insufficient resources are available in the system to complete the function.<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\"><i>The following sections are informative.<\/i><\/p>\n<h2>EXAMPLES <a name=\"EXAMPLES\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">None.<\/p>\n<h2>APPLICATION USAGE <a name=\"APPLICATION USAGE\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">None.<\/p>\n<h2>RATIONALE <a name=\"RATIONALE\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">None.<\/p>\n<h2>FUTURE DIRECTIONS <a name=\"FUTURE DIRECTIONS\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">None.<\/p>\n<h2>SEE ALSO <a name=\"SEE ALSO\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\"><i>Section 2.10.16<\/i>, <i>Use of Options<\/i>, <i>bind<\/i>(), <i>close<\/i>(), <i>endprotoent<\/i>(), <i>setsockopt<\/i>(), <i>socket<\/i>()<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">The Base Definitions volume of POSIX.1-2017, <b><sys_socket.h><\/b>, <b><netinet_in.h><\/b><\/p>\n<h2>COPYRIGHT <a name=\"COPYRIGHT\"><\/a> <\/h2>\n<p style=\"margin-left:11%; margin-top: 1em\">Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology &#8212; Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http:\/\/www.opengroup.org\/unix\/online.html .<\/p>\n<p style=\"margin-left:11%; margin-top: 1em\">Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https:\/\/www.kernel.org\/doc\/man-pages\/reporting_bugs.html .<\/p>\n<hr>\n","protected":false},"excerpt":{"rendered":"<p>  getsockopt \u2014 get the socket options <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3779,1],"tags":[2487,1594],"class_list":["post-5601","post","type-post","status-publish","format-standard","hentry","category-3pm-perl-llamadas-de-bibliotecas","category-sin-categoria","tag-getsockopt","tag-man3p"],"gutentor_comment":0,"_links":{"self":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/5601","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/comments?post=5601"}],"version-history":[{"count":0,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/5601\/revisions"}],"wp:attachment":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/media?parent=5601"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/categories?post=5601"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/tags?post=5601"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}