|RCMD(3)||Linux Programmer's Manual||RCMD(3)|
#include <netdb.h> /* Or <unistd.h> on some systems */
int rcmd(char **restrict ahost, unsigned short inport, const char *restrict locuser, const char *restrict remuser, const char *restrict cmd, int *restrict fd2p);
int rresvport(int *port);
int iruserok(uint32_t raddr, int superuser, const char *ruser, const char *luser); int ruserok(const char *rhost, int superuser, const char *ruser, const char *luser);
int rcmd_af(char **restrict ahost, unsigned short inport, const char *restrict locuser, const char *restrict remuser, const char *restrict cmd, int *restrict fd2p, sa_family_t af);
int rresvport_af(int *port, sa_family_t af);
int iruserok_af(const void *restrict raddr, int superuser, const char *restrict ruser, const char *restrict luser, sa_family_t af); int ruserok_af(const char *rhost, int superuser, const char *ruser, const char *luser, sa_family_t af);
rcmd(), rcmd_af(), rresvport(), rresvport_af(), iruserok(), iruserok_af(), ruserok(), ruserok_af():
Since glibc 2.19: _DEFAULT_SOURCE Glibc 2.19 and earlier: _BSD_SOURCE
If the connection succeeds, a socket in the Internet domain of type SOCK_STREAM is returned to the caller, and given to the remote command as stdin and stdout. If fd2p is nonzero, then an auxiliary channel to a control process will be set up, and a file descriptor for it will be placed in *fd2p. The control process will return diagnostic output from the command (unit 2) on this channel, and will also accept bytes on this channel as being UNIX signal numbers, to be forwarded to the process group of the command. If fd2p is 0, then the stderr (unit 2 of the remote command) will be made the same as the stdout and no provision is made for sending arbitrary signals to the remote process, although you may be able to get its attention by using out-of-band data.
The protocol is described in detail in rshd(8).
If this file does not exist, is not a regular file, is owned by anyone other than the user or the superuser, is writable by anyone other than the owner, or is hardlinked anywhere, the check automatically fails. Zero is returned if the machine name is listed in the hosts.equiv file, or the host and remote username are found in the .rhosts file; otherwise iruserok() and ruserok() return -1. If the local domain (as obtained from gethostname(2)) is the same as the remote domain, only the machine name need be specified.
If the IP address of the remote host is known, iruserok() should be used in preference to ruserok(), as it does not require trusting the DNS server for the remote host's domain.
The rresvport() function returns a valid, bound socket descriptor on success. On failure, it returns -1 and sets errno to indicate the error. The error code EAGAIN is overloaded to mean: "All network ports in use".
For information on the return from ruserok() and iruserok(), see above.
|rcmd (), rcmd_af ()||Thread safety||MT-Unsafe|
|rresvport (), rresvport_af ()||Thread safety||MT-Safe|
|iruserok (), ruserok (), iruserok_af (), ruserok_af ()||Thread safety||MT-Safe locale|