ares_gethostbyname_file(3) [centos man page]
ARES_GETHOSTBYNAME(3) Library Functions Manual ARES_GETHOSTBYNAME(3) NAME
ares_gethostbyname_file - Lookup a name in the system's hosts file SYNOPSIS
#include <ares.h> int ares_gethostbyname_file(ares_channel channel, const char *name, int family, struct hostent **host) DESCRIPTION
The ares_gethostbyname_file function performs a host lookup by name against the system's hosts file (or equivalent local hostname data- base). The channel parameter is required, but no asynchronous queries are performed. Instead, the lookup is done via the same mechanism used to perform 'f' lookups (see the lookups options field in ares_init_options(3)). The parameter name gives the hostname as a NUL-termi- nated C string, and family gives the desired type of address for the resulting host entry. The return value indicates whether the query succeeded and, if not, how it failed. It may have any of the following values: ARES_SUCCESS The host lookup completed successfully and host now points to the result (and must be freed with ares_free_hostent(3)). ARES_ENOTFOUND The hostname name was not found. ARES_EFILE There was a file I/O error while performing the lookup. ARES_ENOMEM Memory was exhausted. On successful completion of the query, the pointer pointed to by host points to a struct hostent containing the address of the host returned by the lookup. The user must free the memory pointed to by host when finished with it by calling ares_free_hostent(3). If the lookup did not complete successfully, host will be NULL. AVAILABILITY
Added in c-ares 1.5.4 SEE ALSO
ares_gethostbyname(3), ares_free_hostent(3), ares_init_options(3) AUTHOR
Brad Spencer Copyright 1998 by the Massachusetts Institute of Technology. 25 July 1998 ARES_GETHOSTBYNAME(3)
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ARES_GETHOSTBYNAME(3) Library Functions Manual ARES_GETHOSTBYNAME(3) NAME
ares_gethostbyname - Initiate a host query by name SYNOPSIS
#include <ares.h> typedef void (*ares_host_callback)(void *arg, int status, int timeouts, struct hostent *hostent) void ares_gethostbyname(ares_channel channel, const char *name, int family, ares_host_callback callback, void *arg) DESCRIPTION
The ares_gethostbyname function initiates a host query by name on the name service channel identified by channel. The parameter name gives the hostname as a NUL-terminated C string, and family gives the desired type of address for the resulting host entry. When the query is complete or has failed, the ares library will invoke callback. Completion or failure of the query may happen immediately, or may happen during a later call to ares_process(3), ares_destroy(3) or ares_cancel(3). The callback argument arg is copied from the ares_gethostbyname argument arg. The callback argument status indicates whether the query succeeded and, if not, how it failed. It may have any of the following values: ARES_SUCCESS The host lookup completed successfully. ARES_ENOTIMP The ares library does not know how to find addresses of type family. ARES_EBADNAME The hostname name is composed entirely of numbers and periods, but is not a valid representation of an Internet address. ARES_ENOTFOUND The address addr was not found. ARES_ENOMEM Memory was exhausted. ARES_ECANCELLED The query was cancelled. ARES_EDESTRUCTION The name service channel channel is being destroyed; the query will not be completed. The callback argument timeouts reports how many times a query timed out during the execution of the given request. On successful completion of the query, the callback argument hostent points to a struct hostent containing the name of the host returned by the query. The callback need not and should not attempt to free the memory pointed to by hostent; the ares library will free it when the callback returns. If the query did not complete successfully, hostent will be NULL. SEE ALSO
ares_process(3), ares_gethostbyaddr(3) AUTHOR
Greg Hudson, MIT Information Systems Copyright 1998 by the Massachusetts Institute of Technology. 25 July 1998 ARES_GETHOSTBYNAME(3)