Execute a command at another PTS Device
Usage:
bash-5.0# ./ptsSSH
Usage: ./ptsSSH [-n] DEVNAME COMMAND
Usage: '-n' is an optional argument if you want to push a new line at the end of the text
Usage: Will require 'sudo' to run if the executable is not setuid root
Examples:
bash-5.0# tty
/dev/pts/0
bash-5.0# ./ptsSSH -n /dev/pts/1 "echo hello world > /dev/pts/0"
bash-5.0# hello world
bash-5.0# ./ptsSSH -n /dev/pts/1 "ps -l | tail -3 > /dev/pts/0"
bash-5.0# 0 S 1000 108238 107706 0 80 0 - 57056 - pts/1 00:00:00 bash
4 R 1000 108767 108238 0 80 0 - 54699 - pts/1 00:00:00 ps
0 S 1000 108768 108238 0 80 0 - 53833 - pts/1 00:00:00 tail
bash-5.0# ./ptsSSH -n /dev/pts/1 "whoami > /dev/pts/0"
bash-5.0# user1
C Source:
/*https://stackoverflow.com/a/40190182/13849027*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <string.h>
#include <unistd.h>
void print_help(char *prog_name) {
printf("Usage: %s [-n] DEVNAME COMMAND\n", prog_name);
printf("Usage: '-n' is an optional argument if you want to push a new line at the end of the text\n");
printf("Usage: Will require 'sudo' to run if the executable is not setuid root\n");
exit(1);
}
int main (int argc, char *argv[]) {
char *cmd, *nl = "\n";
int i, fd;
int devno, commandno, newline;
int mem_len;
devno = 1; commandno = 2; newline = 0;
if (argc < 3) {
print_help(argv[0]);
}
if (argc > 3 && argv[1][0] == '-' && argv[1][1] == 'n') {
devno = 2; commandno = 3; newline=1;
} else if (argc > 3 && argv[1][0] == '-' && argv[1][1] != 'n') {
printf("Invalid Option\n");
print_help(argv[0]);
}
fd = open(argv[devno],O_RDWR);
if(fd == -1) {
perror("open DEVICE");
exit(1);
}
mem_len = 0;
for (i = commandno; i < argc; i++) {
mem_len += strlen(argv[i]) + 2;
if (i > commandno) {
cmd = (char *)realloc((void *)cmd, mem_len);
} else { // i == commandno
cmd = (char *)malloc(mem_len);
}
strcat(cmd, argv[i]);
strcat(cmd, " ");
}
if (newline == 0)
usleep(225000);
for (i = 0; cmd[i]; i++)
ioctl (fd, TIOCSTI, cmd+i);
if (newline == 1)
ioctl (fd, TIOCSTI, nl);
close(fd);
free((void *)cmd);
exit (0);
}
