sd_is_fifo(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON

SD_IS_FIFO(3)                  sd_is_fifo                  SD_IS_FIFO(3)

NAME         top

       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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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 filename. Special files in this context are character
       device nodes and files in /proc/ or /sys/.

RETURN VALUE         top

       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.

NOTES         top

       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.

SEE ALSO         top

       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).

COLOPHON         top

       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 2021-06-20.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-06-19.)  If you discover 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 249                                                SD_IS_FIFO(3)

Pages that refer to this page: sd-daemon(3)sd_listen_fds(3)systemd.directives(7)systemd.index(7)