|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_IS_FIFO(3) sd_is_fifo SD_IS_FIFO(3)
sd_is_fifo, sd_is_socket, sd_is_socket_inet, sd_is_socket_unix,
sd_is_socket_sockaddr, sd_is_mq, sd_is_special - Check the type of a
file descriptor
#include <systemd/sd-daemon.h>
int sd_is_fifo(int fd, const char *path);
int sd_is_socket(int fd, int family, int type, int listening);
int sd_is_socket_inet(int fd, int family, int type, int listening,
uint16_t port);
int sd_is_socket_sockaddr(int fd, int type,
const struct sockaddr *addr,
unsigned addr_len, int listening);
int sd_is_socket_unix(int fd, int type, int listening,
const char *path, size_t length);
int sd_is_mq(int fd, const char *path);
int sd_is_special(int fd, const char *path);
sd_is_fifo() may be called to check whether the specified file
descriptor refers to a FIFO or pipe. If the path parameter is not
NULL, it is checked whether the FIFO is bound to the specified file
system path.
sd_is_socket() may be called to check whether the specified file
descriptor refers to a socket. If the family parameter is not
AF_UNSPEC, it is checked whether the socket is of the specified
family (AF_UNIX, AF_INET, ...). If the type parameter is not 0, it is
checked whether the socket is of the specified type (SOCK_STREAM,
SOCK_DGRAM, ...). If the listening parameter is positive, it is
checked whether the socket is in accepting mode, i.e. listen() has
been called for it. If listening is 0, it is checked whether the
socket is not in this mode. If the parameter is negative, no such
check is made. The listening parameter should only be used for stream
sockets and should be set to a negative value otherwise.
sd_is_socket_inet() is similar to sd_is_socket(), but optionally
checks the IPv4 or IPv6 port number the socket is bound to, unless
port is zero. For this call family must be passed as either
AF_UNSPEC, AF_INET, or AF_INET6.
sd_is_socket_sockaddr() is similar to sd_is_socket_inet(), but checks
if the socket is bound to the address specified by addr. The family
specified by addr must be either AF_INET or AF_INET6 and addr_len
must be large enough for that family. If addr specifies a non-zero
port, it is also checked if the socket is bound to this port. In
addition, for IPv6, if addr specifies non-zero sin6_flowinfo or
sin6_scope_id, it is checked if the socket has the same values.
sd_is_socket_unix() is similar to sd_is_socket() but optionally
checks the AF_UNIX path the socket is bound to, unless the path
parameter is NULL. For normal file system AF_UNIX sockets, set the
length parameter to 0. For Linux abstract namespace sockets, set the
length to the size of the address, including the initial 0 byte, and
set the path to the initial 0 byte of the socket address.
sd_is_mq() may be called to check whether the specified file
descriptor refers to a POSIX message queue. If the path parameter is
not NULL, it is checked whether the message queue is bound to the
specified name.
sd_is_special() may be called to check whether the specified file
descriptor refers to a special file. If the path parameter is not
NULL, it is checked whether the file descriptor is bound to the
specified file name. Special files in this context are character
device nodes and files in /proc or /sys.
On failure, these calls return a negative errno-style error code. If
the file descriptor is of the specified type and bound to the
specified address, a positive return value is returned, otherwise
zero.
These APIs are implemented as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
Internally, these function use a combination of fstat() and
getsockname() to check the file descriptor type and where it is bound
to.
systemd(1), sd-daemon(3), sd_listen_fds(3), systemd.service(5),
systemd.socket(5), ip(7), ipv6(7), unix(7), fifo(7), mq_overview(7),
socket(7).
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
systemd 234 SD_IS_FIFO(3)
Pages that refer to this page: sd-daemon(3), sd_listen_fds(3), systemd.directives(7), systemd.index(7)