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

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 );

LIBRARY
  Standard C Library (libc)

PARAMETERS
  host
      Contains the name of a remote host that is listed in the /etc/hosts
      file or /etc/resolv.conffile.  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.

SEE ALSO
  Functions: getservbyname(3), rcmd(3), rresvport(3), ruserok(3).

  Commands: rexecd(8).

Index for Section 3

Alphabetical listing for R

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