/* -------------------- SAS/C Sample Program --------------------
 *
 * MODULE: rexeccmd.c - Main routine for sample rexec command
 * SYNTAX: rexec host username password cmd-words
 *
 * NOTE:   This command does not support sending input to the remote
 *         program. Non-UNIX implementations often restrict
 *         select() to sockets. Thus, there is no portable
 *         way to wait for sockets and "stdin" simultaneously.
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
   
#ifdef __SASC__
Static void to_ebcdic(char *buf, size_t n);
#endif
   
#define EXEC_PORT 512  /* Well-known port for exec server. */
   
Main(int argc, char *argv[]) {
int primary;     /* Socket for stdin/stdout. */
int secondary;   /* Socket for stderr. */
fd_set recv_set; /* Set of sockets we will wait on. */
char buf[256];   /* Set of buffer for incoming data. */
char *host;      /* Pointer to hostname. */
int port;        /* Port for exec server */
char cmd[512];   /* Command string. */
struct servent *serv; /* exec server information. */
int i, n, rc;
   
/*
 * Handle command line arguments.
 *    argv[1] = hostname
 *    argv[2] = username
 *    argv[3] = password
 *    argv[4] = first command word
 *    ...
 *    argv[argc-1] = last command word
 */
if ((argc < 5) || (*argv[1] == '?') || (strcmp(argv[1], "-?") == 0)) {
    printf("Usage: %s hostname username password cmd-words\n",
                Argv[0]);
    exit(EXIT_FAILURE);
    }
host = argv[1];  /* Pointer can be modified by rexec() call. */
   
/* Build up command string from remaining arguments. */
strcpy(cmd, argv[4]);
for (i = 5; i < argc; i++) {
     strcat(cmd, " ");
     strcat(cmd, argv[i]);
     }
   
/* Lookup standard REXEC server port. */
serv = getservbyname("exec","tcp");
if (serv == NULL) {
    perror("getservbyname failed");
    port = EXEC_PORT;  /* Assume the usual. */
    }
else
    port = serv->s_port;
   
primary = rexec(&host, port, argv[2], argv[3], cmd, &secondary);
if (primary < 0) return EXIT_FAILURE;
   
FD_ZERO(&recv_set);
while ((primary >= 0) || (secondary >= 0)) {
    /*
     * Wait for incoming data on both sockets.
     *   select() clears bits from the mask, so we must reset
     *   the bits each time through the loop.
     */
    if (primary >= 0)   FD_SET(primary, &recv_set);
    if (secondary >= 0) FD_SET(secondary, &recv_set);

    rc = select(FD_SETSIZE, &recv_set, NULL, NULL, NULL);
    if (rc < 0) {
        perror("select failed");
        exit(EXIT_FAILURE);
        }
   
    /*
     * If incoming data available on primary...
     */
    if ((primary >= 0) /* Not end of file yet. */
    &&  (FD_ISSET(primary, &recv_set))) {
        /* recv it (or at least some of it). */
        n = recv(primary, buf, sizeof(buf), 0);
        if (n == 0)
            primary = -1;  /* Flag end-of-file on primary. */
        else if (n < 0) {
            perror("recv failed on remote program's standard output");
            exit(EXIT_FAILURE);
            }
        else {
            #ifdef __SASC__
            to_ebcdic(buf, n);
            #endif
            fwrite(buf, n, 1, stdout); /* Write to local stdout */
            }
        }

    /*
     * If incoming data available on secondary...
     */
    if ((secondary >= 0)  /* Not end of file yet. */
    &&  (FD_ISSET(secondary, &recv_set))) {
        n = recv(secondary, buf, sizeof(buf)-1, 0);
        if (n == 0)
            secondary = -1;  /* Flag end-of-file on secondary. */
        else if (n < 0) {
            perror("recv failed on remote program's standard error");
            exit(EXIT_FAILURE);
            }
        else {
            #ifdef __SASC__
            to_ebcdic(buf, n);
            #endif
            fwrite(buf, n, 1, stderr); /* Write to local stderr */
            }
        }
    }  /* End of while loop. */
   
return EXIT_SUCCESS;
}
   
#ifdef __SASC__   /* Need conversion to EBCDIC */
/*
 *   htoncs() is a SAS/C specific function which converts
 *   a character from ASCII to EBCDIC.
 */
#include <netinet/in.h> /* prototype for htoncs(). */
static void to_ebcdic(char *buf, size_t n) {
int i;
for (i = 0; i < n; i++) buf[i] = ntohcs(buf[i]);
return;
}
#endif