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_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_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_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.

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)

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
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       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 231                                                    SD_IS_FIFO(3)