1SD_IS_FIFO(3)                     sd_is_fifo                     SD_IS_FIFO(3)
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NAME

6       sd_is_fifo, sd_is_socket, sd_is_socket_inet, sd_is_socket_unix,
7       sd_is_mq, sd_is_special - Check the type of a file descriptor
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SYNOPSIS

10       #include <systemd/sd-daemon.h>
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12       int sd_is_fifo(int fd, const char *path);
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14       int sd_is_socket(int fd, int family, int type, int listening);
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16       int sd_is_socket_inet(int fd, int family, int type, int listening,
17                             uint16_t port);
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19       int sd_is_socket_unix(int fd, int type, int listening,
20                             const char *path, size_t length);
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22       int sd_is_mq(int fd, const char *path);
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24       int sd_is_special(int fd, const char *path);
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DESCRIPTION

27       sd_is_fifo() may be called to check whether the specified file
28       descriptor refers to a FIFO or pipe. If the path parameter is not NULL,
29       it is checked whether the FIFO is bound to the specified file system
30       path.
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32       sd_is_socket() may be called to check whether the specified file
33       descriptor refers to a socket. If the family parameter is not
34       AF_UNSPEC, it is checked whether the socket is of the specified family
35       (AF_UNIX, AF_INET, ...). If the type parameter is not 0, it is checked
36       whether the socket is of the specified type (SOCK_STREAM, SOCK_DGRAM,
37       ...). If the listening parameter is positive, it is checked whether the
38       socket is in accepting mode, i.e.  listen() has been called for it. If
39       listening is 0, it is checked whether the socket is not in this mode.
40       If the parameter is negative, no such check is made. The listening
41       parameter should only be used for stream sockets and should be set to a
42       negative value otherwise.
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44       sd_is_socket_inet() is similar to sd_is_socket(), but optionally checks
45       the IPv4 or IPv6 port number the socket is bound to, unless port is
46       zero. For this call family must be passed as either AF_UNSPEC, AF_INET,
47       or AF_INET6.
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49       sd_is_socket_unix() is similar to sd_is_socket() but optionally checks
50       the AF_UNIX path the socket is bound to, unless the path parameter is
51       NULL. For normal file system AF_UNIX sockets, set the length parameter
52       to 0. For Linux abstract namespace sockets, set the length to the size
53       of the address, including the initial 0 byte, and set the path to the
54       initial 0 byte of the socket address.
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56       sd_is_mq() may be called to check whether the specified file descriptor
57       refers to a POSIX message queue. If the path parameter is not NULL, it
58       is checked whether the message queue is bound to the specified name.
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60       sd_is_special() may be called to check whether the specified file
61       descriptor refers to a special file. If the path parameter is not NULL,
62       it is checked whether the file descriptor is bound to the specified
63       file name. Special files in this context are character device nodes and
64       files in /proc or /sys.
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RETURN VALUE

67       On failure, these calls return a negative errno-style error code. If
68       the file descriptor is of the specified type and bound to the specified
69       address, a positive return value is returned, otherwise zero.
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NOTES

72       These APIs are implemented as a shared library, which can be compiled
73       and linked to with the libsystemd pkg-config(1) file.
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75       Internally, these function use a combination of fstat() and
76       getsockname() to check the file descriptor type and where it is bound
77       to.
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SEE ALSO

80       systemd(1), sd-daemon(3), sd_listen_fds(3), systemd.service(5),
81       systemd.socket(5)
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85systemd 219                                                      SD_IS_FIFO(3)
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