rexec(3SOCKET) Sockets Library Functions rexec(3SOCKET)NAME
rexec, rexec_af - return stream to a remote command
SYNOPSIS
cc [ flag ... ] file... -lsocket -lnsl [ library... ]
#include <netdb.h>
#include <unistd.h>
int rexec(char **ahost, unsigned short inport, const char *user, const
char *passwd, const char *cmd, int *fd2p);
int rexec_af(char **ahost, unsigned short inport, const char *user,
const char *passwd, const char *cmd, int *fd2p, int af);
DESCRIPTION
The rexec() and rexec_af() functions look up the host ahost using
getaddrinfo(3SOCKET) and return −1 if the host does not exist. Other‐
wise ahost is set to the standard name of the host. The username and
password are used in remote host authentication. When a username and
password are not specified, the .netrc file in the user's home direc‐
tory is searched for the appropriate information. If the search fails,
the user is prompted for the information.
The rexec() function always returns a socket of the AF_INET address
family. The rexec_af() function supports AF_INET, AF_INET6, or
AF_UNSPEC for the address family. An application can choose which type
of socket is returned by passing AF_INET or AF_INET6 as the address
family. The use of AF_UNSPEC means that the caller will accept any
address family. Choosing AF_UNSPEC provides a socket that best suits
the connectivity to the remote host.
The port inport specifies which DARPA Internet port to use for the con‐
nection. The port number used must be in network byte order, as sup‐
plied by a call to htons(3XNET). The protocol for connection is
described in detail in in.rexecd(1M).
If the call succeeds, a socket of type SOCK_STREAM is returned to the
caller, and given to the remote command as its standard input and stan‐
dard output. If fd2p is non-zero, an auxiliary channel to a control
process is set up and a file descriptor for it is placed in *fd2p. The
control process returns diagnostic output (file descriptor 2), from the
command on the auxiliary channel. The control process also accepts
bytes on this channel as signal numbers to be forwarded to the process
group of the command. If fd2p is 0, the standard error (file descriptor
2) of the remote command is made the same as its standard output. No
provision is made for sending arbitrary signals to the remote process,
other than possibly sending out-of-band data.
There is no way to specify options to the socket() call made by the
rexec() or rexec_af()functions.
RETURN VALUES
If rexec() succeeds, a file descriptor number is returned of the socket
type SOCK_STREAM and the address family AF_INET. The parameter *ahost
is set to the standard name of the host. If the value of fd2p is other
than NULL, a file descriptor number is placed in *fd2p which represents
the standard error stream of the command.
If rexec_af() succeeds, the routine returns a file descriptor number of
the socket type SOCK_STREAM in the address family AF_INET or AF_INET6,
as determined by the value of the af parameter.
If either rexec() or rexec_af() fails, −1 is returned.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Unsafe │
└─────────────────────────────┴─────────────────────────────┘
This interface is Unsafe in multithreaded applications. Unsafe inter‐
faces should be called only from the main thread.
SEE ALSOin.rexecd(1M), getaddrinfo(3SOCKET), gethostbyname(3NSL), getservby‐
name(3SOCKET), htons(3XNET), socket(3SOCKET), attributes(5)SunOS 5.10 10 Feb 2004 rexec(3SOCKET)
