Hide cursor on remote terminal

Question

I have an open socket to a remote terminal. Using the answer to "Force telnet client into character mode" I was able to put that terminal into character mode.

My question is, how do I hide the cursor in the remote terminal using this method?

Exurbanite

Answer 1

This is something that the ncurses library can do for you.

The curs_set() function can make the cursor invisible.

Vitiated

Answer 2

To expand upon mjh2007's answer, the following c/c++ code will implement sending the escape codes to the terminal, and is slightly more readable than raw hex numbers.

void showCursor(bool show) const {
#define CSI "\e["
  if (show) {
    fputs(CSI "?25h", stdout);
  }
  else {
    fputs(CSI "?25l", stdout);
  }
#undef CSI
}

Fides

Do not hard-code the terminal control codes unless you have no other choice. Use ncurses to look up the appropriate codes for the current $TERM value unless you cannot use ncurses for some reason. – Inlier

I agree that ncursrs would be best, but if for some reason you don't have access to that, this might be a "good enough" solution for some cases. – Fides

Powershell seems to respect this sequence if it's preceded by a SGR escape sequence or a cursor move sequence, but not if it's preceded by some other sequences including another instance of ?25! \e[0m\e[?25h seems to work fine. – Pertain

As for the escape codes: \e[?25h and \e[?25l. To memorize it, remember that L stands for Lehidden and H stands for HonestlyTheCursorWillBeVisible. – Disrupt

Also, no offense or anything, but using ncurses for this is like downloading a web-browser to read a text file :) @ChrisPage – Disrupt

Answer 3

If the terminal you are using supports ANSI format you should be able to send the following escape codes:

Hide the cursor: 0x9B 0x3F 0x32 0x35 0x6C
Show the cursor: 0x9B 0x3F 0x32 0x35 0x68

Oehsen

I know this is a few years old but where did you get that command? Is there a link with other escape codes in? – Mazdaism

Do not hard-code the terminal control codes unless you have no other choice. Use ncurses to look up the appropriate codes for the current $TERM value unless you cannot use ncurses for some reason. – Inlier

Like my code is running on a PIC microprocessor w/ 8KB of ROM? – Oehsen

Answer 4

If this is using the 'telnet' application then your app should send 'IAC WILL ECHO' to disable echoing on their remote side. This is useful for entering passwords or if your app is doing the echoing.

#define TEL_IAC "\377"
#define TEL_WILL "\373"
#define TEL_ECHO "\001"

char buf[4];
snprintf(buf, sizeof(buf), "%c%c%c" TEL_IAC, TEL_WILL, TEL_ECHO);
write(sock, buf, sizeof(buf));

Or

write(sock, TEL_IAC TEL_WILL TEL_ECHO, 3);

Hope this helps.

Samaritan

The question seems to be about hiding the cursor, not hiding user input. – Inlier