pure-bash-bible/manuscript/chapter17.txt

# INFORMATION ABOUT THE TERMINAL

## Get the terminal size in lines and columns (*from a script*)

This is handy when writing scripts in pure bash and `stty`/`tput` can’t be
called.

**Example Function:**

```sh
get_term_size() {
    # Usage: get_term_size

    # (:;:) is a micro sleep to ensure the variables are
    # exported immediately.
    shopt -s checkwinsize; (:;:)
    printf '%s\n' "$LINES $COLUMNS"
}
```

**Example Usage:**

```shell
# Output: LINES COLUMNS
$ get_term_size
15 55
```

## Get the terminal size in pixels

**CAVEAT**: This does not work in some terminal emulators.

**Example Function:**

```sh
get_window_size() {
    # Usage: get_window_size
    printf '%b' "${TMUX:+\\ePtmux;\\e}\\e[14t${TMUX:+\\e\\\\}"
    IFS=';t' read -d t -t 0.05 -sra term_size
    printf '%s\n' "${term_size[1]}x${term_size[2]}"
}
```

**Example Usage:**

```shell
# Output: WIDTHxHEIGHT
$ get_window_size
1200x800

# Output (fail):
$ get_window_size
x
```

## Get the current cursor position

This is useful when creating a TUI in pure bash.

**Example Function:**

```sh
get_cursor_pos() {
    # Usage: get_cursor_pos
    IFS='[;' read -p $'\e[6n' -d R -rs _ y x _
    printf '%s\n' "$x $y"
}
```

**Example Usage:**

```shell
# Output: X Y
$ get_cursor_pos
1 8
```

<!-- CHAPTER END -->