Linux Manuals session 3

NAME ares_save_options – Save configuration values obtained from initialized ares_channel SYNOPSIS #include <ares.h> int ares_save_options(ares_channel channel, struct ares_options *options, int *optmask) DESCRIPTION The ares_save_options(3) function saves the channel data identified by channel, into the options struct identified by options, and saves the mask of options which are set to the integer pointer (passed by reference)…

NAME ares_query – Initiate a single-question DNS query SYNOPSIS #include <ares.h> typedef void (*ares_callback)(void *arg, int status, void ares_query(ares_channel channel, const char *name, int dnsclass, int type, ares_callback callback, DESCRIPTION The ares_query function initiates a single-question DNS query on the name service channel identified by channel. The parameter name gives the query name as a…

NAME ares_process – Process events for name resolution SYNOPSIS #include <ares.h> void ares_process(ares_channel channel, fd_set *read_fds, void ares_process_fd(ares_channel channel, ares_socket_t read_fd, DESCRIPTION The ares_process(3) function handles input/output events and timeouts associated with queries pending on the name service channel identified by channel. The file descriptor sets pointed to by read_fds and write_fds should have file…

NAME ares_parse_txt_reply – Parse a reply to a DNS query of type TXT SYNOPSIS #include <ares.h> int ares_parse_txt_reply(const unsigned char *abuf, int alen, struct ares_txt_reply **txt_out); DESCRIPTION The ares_parse_txt_reply function parses the response to a query of type TXT into a linked list (one element per sub-string) of struct ares_txt_reply The parameters abuf and alen…

NAME ares_parse_srv_reply – Parse a reply to a DNS query of type SRV SYNOPSIS #include <ares.h> int ares_parse_srv_reply(const unsigned char *abuf, int alen, struct ares_srv_reply **srv_out); DESCRIPTION The ares_parse_srv_reply function parses the response to a query of type SRV into a linked list of struct ares_srv_reply The parameters abuf and alen give the contents of…

NAME ares_parse_soa_reply – Parse a reply to a DNS query of type SOA SYNOPSIS #include <ares.h> int ares_parse_soa_reply(const unsigned char* abuf, int alen, DESCRIPTION The ares_parse_soa_reply function parses the response to a query of type SOA into a struct ares_soa_reply. The parameters abuf and alen give the contents of the response. The result is stored…

NAME ares_parse_ptr_reply – Parse a reply to a DNS query of type PTR into a hostent SYNOPSIS #include <ares.h> int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr, int addrlen, int family, DESCRIPTION The ares_parse_ptr_reply function parses the response to a query of type PTR into a struct hostent. The parameters abuf and alen…

NAME ares_parse_ns_reply – Parse a reply to a DNS query of type NS into a hostent SYNOPSIS #include <ares.h> int ares_parse_ns_reply(const unsigned char *abuf, int alen, struct hostent **host); DESCRIPTION The ares_parse_ns_reply function parses the response to a query of type NS into a struct hostent. The parameters abuf and alen give the contents of…

NAME ares_parse_naptr_reply – Parse a reply to a DNS query of type NAPTR SYNOPSIS #include <ares.h> int ares_parse_naptr_reply(const unsigned char *abuf, int alen, struct ares_naptr_reply **naptr_out); DESCRIPTION The ares_parse_naptr_reply function parses the response to a query of type NAPTR into a linked list of struct ares_naptr_reply The parameters abuf and alen give the contents of…

NAME ares_parse_mx_reply – Parse a reply to a DNS query of type MX SYNOPSIS #include <ares.h> int ares_parse_mx_reply(const unsigned char *abuf, int alen, struct ares_mx_reply **mx_out); DESCRIPTION The ares_parse_mx_reply function parses the response to a query of type MX into a linked list of struct ares_mx_reply The parameters abuf and alen give the contents of…

NAME ares_parse_aaaa_reply – Parse a reply to a DNS query of type AAAA SYNOPSIS #include <ares.h> int ares_parse_aaaa_reply(const unsigned char *abuf, int alen, struct hostent **host, struct ares_addr6ttl *addrttls, int *naddrttls); DESCRIPTION The ares_parse_aaaa_reply function parses the response to a query of type AAAA into a struct hostent and/or an array of struct ares_addr6ttl. The…

NAME ares_parse_a_reply – Parse a reply to a DNS query of type A SYNOPSIS #include <ares.h> int ares_parse_a_reply(const unsigned char *abuf, int alen, struct hostent **host, struct ares_addrttl *addrttls, int *naddrttls); DESCRIPTION The ares_parse_a_reply function parses the response to a query of type A into a struct hostent and/or an array of struct ares_addrttls. The…

NAME ares_mkquery – Compose a single-question DNS query buffer SYNOPSIS #include <ares.h> int ares_mkquery(const char *name, int dnsclass, int type, DESCRIPTION Deprecated function. See ares_create_query(3) instead! The ares_mkquery function composes a DNS query with a single question. The parameter name gives the query name as a NUL-terminated C string of period-separated labels optionally ending with…

NAME ares_library_init – c-ares library initialization SYNOPSIS #include <ares.h> int ares_library_init(int flags) cc file.c – lcares DESCRIPTION The ares_library_init function performs initializations internally required by the c-ares library that must take place before any other function provided by c-ares can be used in a program. This function must be called at least once within the…

NAME ares_library_cleanup – c-ares library deinitialization SYNOPSIS #include <ares.h> void ares_library_cleanup(void) cc file.c – lcares DESCRIPTION The ares_library_cleanup function uninitializes the c-ares library, freeing all resources previously acquired by ares_library_init(3) when the library was initialized, provided there was only one single previous call to ares_library_init(3). If there was more than one previous call to ares_library_init(3),…

NAME ares_init, ares_init_options – Initialize a resolver channel SYNOPSIS #include <ares.h> int ares_init(ares_channel *channelptr) int ares_init_options(ares_channel *channelptr, struct ares_options *options, int optmask) cc file.c – lcares DESCRIPTION The ares_init function initializes a communications channel for name service lookups. If it returns successfully, ares_init will set the variable pointed to by channelptr to a handle used…

NAME ares_init, ares_init_options – Initialize a resolver channel SYNOPSIS #include <ares.h> int ares_init(ares_channel *channelptr) int ares_init_options(ares_channel *channelptr, struct ares_options *options, int optmask) cc file.c – lcares DESCRIPTION The ares_init function initializes a communications channel for name service lookups. If it returns successfully, ares_init will set the variable pointed to by channelptr to a handle used…

NAME ares_inet_pton – convert an IPv4 or IPv6 address from text to binary form SYNOPSIS #include <ares.h> const char *ares_inet_pton(int af, const char *src, void *dst); DESCRIPTION This is a portable version with the identical functionality of the commonly available inet_pton. The ares_inet_pton() function converts the address in its standard text presentation form into its…

NAME ares_inet_ntop – convert a network format address to presentation format SYNOPSIS #include <ares.h> const char * ares_inet_ntop(int af, const void *src, char *dst, ares_socklen_t size); DESCRIPTION This is a portable version with the identical functionality of the commonly available inet_ntop. The ares_inet_ntop() function converts a numeric address into a text string suitable for presentation….

NAME ares_getsock – get socket descriptors to wait on SYNOPSIS #include <ares.h> int ares_getsock(ares_channel channel, ares_socket_t *socks, int numsocks); DESCRIPTION The ares_getsock function retrieves the set of socket descriptors which the calling application should wait on for reading and/or writing for the processing of name service queries pending on the name service channel identified by…