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rexec(3)
NAME
  rexec, rexec_r - Allow command execution on a remote host

LIBRARY
  Standard C Library (libc.a)

SYNOPSIS
  #include <netdb.h>

  #include <unistd.h>
  int rexec(
	  char **host,
	  int port,
	  char *user,
	  char *passwd,
	  char *command,
	  int *err_file_desc);

  The following function is supported in order to maintain backward
  compatibility with previous versions of the operating system.

  int rexec_r(
	  char **host,
	  int port,
	  char *user,
	  char *passwd,
	  char *command,
	  int *err_file_desc,
	  struct hostent_data *host_data);

PARAMETERS
  host	    Contains the name of a remote host that is listed in the
	    /etc/hosts file or /etc/resolv.conf file.  If the name of the
	    host is not found in either file, the rexec() fails.

  port	    Specifies the well-known Internet port to use for the connection.
	    A pointer to the structure that contains the necessary port can
	    be obtained by issuing the following library call:
		 getservbyname("exec", "tcp")

  user	    Points to a user ID that is valid on the host.

  passwd    Points to the password of the specified user ID on the host.

  command   Points to the name of the command to be executed at the remote
	    host.

  err_file_desc
	    Specifies the file to which standard error from the remote
	    command is sent.

	    If the err_file_desc parameter is 0 (zero), the standard error of
	    the remote command is the same as standard output.	No provision
	    is made for sending arbitrary signals to the remote process.  In
	    this case, however, it may be possible to send out-of-band data
	    to the remote command.

	    If the err_file_desc parameter is nonzero, an auxiliary channel
	    to a control process is set up, and a descriptor for it is placed
	    in the err_file_desc parameter.  The control process provides
	    diagnostic output from the remote command on this channel and
	    also accepts bytes as signal numbers to be forwarded to the
	    process group of the command.  This diagnostic information does
	    not include remote authorization failure, since this connection
	    is set up after authorization has been verified.

  host_data Per-thread data for reentrant version.

DESCRIPTION
  The rexec() (remote execution) function allows the calling process to
  execute commands on a remote host.

  If the rexec() connection succeeds, a socket in the Internet domain of type
  SOCK_STREAM is returned to the calling process and is given to the remote
  command as standard input and standard output.

  The user and passwd parameters specify a valid user ID and the associated
  password for that user on the remote host.  If the user and passwd
  parameters are not supplied, the rexec() function takes the following
  actions until finding a user ID and password to send to the remote host:

   1.  It searches the current environment for the user ID and password on
       the remote host.

   2.  It searches the user's home directory for a file called $HOME/.netrc
       that contains a user ID and password.

   3.  It prompts the user for a user ID and password.

  Note that action 3 does not apply when using rexec_r().

NOTES
  The rexec_r() function is the reentrant version of rexec().  It is
  supported in order to maintain backward compatibility with previous
  versions of the operating system.  The netdb.h header file defines the
  hostent_data structures.

RETURN VALUES
  Upon successful completion, the system returns a socket descriptor to the
  remote command.  Otherwise, a value of -1 is returned, indicating that the
  specified hostname does not exist.

FILES
  /etc/hosts
	    Contains hostnames and their addresses for hosts in a network.
	    This file is used to resolve a hostname into an Internet address.

  /etc/resolv.conf
	    Contains the name server and domain name.

  $HOME/.netrc
	    Contains automatic login information.

RELATED INFORMATION
  Functions: getservbyname(3), rcmd(3), rresvport(3), ruserok(3).

  Commands: rexecd(8).

Index for Section 3

Alphabetical listing for R

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