rexec_af(3socket)

1rexec(3SOCKET)             Sockets Library Functions            rexec(3SOCKET)
2
3
4

NAME

6       rexec, rexec_af - return stream to a remote command
7

SYNOPSIS

9       cc [ flag ... ] file... -lsocket  -lnsl  [ library... ]
10       #include <netdb.h>
11       #include <unistd.h>
12
13       int rexec(char **ahost, unsigned short inport, const char *user,
14            const char *passwd, const char *cmd, int *fd2p);
15
16
17       int rexec_af(char **ahost, unsigned short inport, const char *user,
18            const char *passwd, const char *cmd, int *fd2p, int af);
19
20

DESCRIPTION

22       The  rexec()  and  rexec_af()  functions  look  up the host ahost using
23       getaddrinfo(3SOCKET) and return −1 if the host does not  exist.  Other‐
24       wise  ahost  is  set to the standard name of the host. The username and
25       password are used in remote host authentication. When  a  username  and
26       password  are  not specified, the .netrc file in the user's home direc‐
27       tory is searched for the appropriate information. If the search  fails,
28       the user is prompted for the information.
29
30
31       The  rexec()  function  always  returns a socket of the AF_INET address
32       family.  The  rexec_af()  function  supports  AF_INET,   AF_INET6,   or
33       AF_UNSPEC  for the address family. An application can choose which type
34       of socket is returned by passing AF_INET or  AF_INET6  as  the  address
35       family.  The  use  of  AF_UNSPEC  means that the caller will accept any
36       address family. Choosing AF_UNSPEC provides a socket  that  best  suits
37       the connectivity to the remote host.
38
39
40       The port inport specifies which DARPA Internet port to use for the con‐
41       nection. The port number used must be in network byte  order,  as  sup‐
42       plied  by  a  call  to  htons(3XNET).  The  protocol  for connection is
43       described in detail in in.rexecd(1M).
44
45
46       If the call succeeds, a socket of type SOCK_STREAM is returned  to  the
47       caller, and given to the remote command as its standard input and stan‐
48       dard output. If fd2p is non-zero, an auxiliary  channel  to  a  control
49       process  is set up and a file descriptor for it is placed in *fd2p. The
50       control process returns diagnostic output (file descriptor 2), from the
51       command  on  the  auxiliary  channel.  The control process also accepts
52       bytes on this channel as signal numbers to be forwarded to the  process
53       group of the command. If fd2p is 0, the standard error (file descriptor
54       2) of the remote command is made the same as its  standard  output.  No
55       provision  is made for sending arbitrary signals to the remote process,
56       other than possibly sending out-of-band data.
57
58
59       There is no way to specify options to the socket()  call  made  by  the
60       rexec() or rexec_af()functions.
61

RETURN VALUES

63       If rexec() succeeds, a file descriptor number is returned of the socket
64       type SOCK_STREAM and the address family AF_INET. The  parameter  *ahost
65       is  set to the standard name of the host. If the value of fd2p is other
66       than NULL, a file descriptor number is placed in *fd2p which represents
67       the standard error stream of the command.
68
69
70       If rexec_af() succeeds, the routine returns a file descriptor number of
71       the socket type SOCK_STREAM in the address family AF_INET or  AF_INET6,
72       as determined by the value of the af parameter.
73
74
75       If either rexec() or rexec_af() fails, −1 is returned.
76

ATTRIBUTES

78       See attributes(5) for descriptions of the following attributes:
79
80
81
82
83       ┌─────────────────────────────┬─────────────────────────────┐
84       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
85       ├─────────────────────────────┼─────────────────────────────┤
86       │MT-Level                     │Unsafe                       │
87       └─────────────────────────────┴─────────────────────────────┘
88
89
90       This  interface  is Unsafe in multithreaded applications. Unsafe inter‐
91       faces should be called only from the main thread.
92

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUES

ATTRIBUTES

SEE ALSO