text: tcinject()
  Inject characters into a device's input buffer
  Synopsis:
  #include <termios.h> int tcinject( int fd, char *buf, int n );
  Arguments:
  - fildes
  - A file descriptor that's associated with the device whose input buffer you want to add characters to.
  - buf
  - A pointer to a buffer that contains the characters that you want to insert.
  - n
  - The number of characters to insert. If n is positive, the characters are written to the canonical (edited) queue. If n is negative, the characters are written to the raw queue.
  Library:
  libc
  Use the -l c option to qcc to link against this library. This library is usually included automatically.
  Description:
  The tcinject() function injects n characters pointed to by buf into the input buffer of the device given in fd.
  Note that while injecting into the canonical queue, editing characters in buf are acted upon as though the user entered them directly from the device. If buf doesn't contain a newline (‘\n’), carriage return (‘\r’) or a data-forwarding character such as an EOF, data doesn't become available for reading. If buf does contain a data-forwarding character, it should contain only one as the last character in buf.
  This function is useful for implementing command-line recall algorithms by injecting recalled lines into the canonical queue.
  Returns:
  Errors:
  - EBADF
  - The fd argument is invalid or the file isn't opened for read.
  - ENOSYS
  - This function isn't supported for the device opened.
  Examples:
  #include <stdio.h> #include <stdlib.h> #include <termios.h> int main( void ) { char *p = "echo Hello world!\n"; /* Inject the line all at once */ tcinject(0, p, strlen(p)); /* Inject the line one character at a time */ while(*p) tcinject(0, p++, 1); return EXIT_SUCCESS; }