tset Command in Linux
The tset command in Linux initializes the terminal. It is used to set up the terminal type and initialize terminal settings, such as special characters and modes. It retrieves the terminal mode settings by testing them in order: standard error, standard output, standard input, and finally /dev/tty. This is especially useful in scripts or login sessions to ensure the terminal behaves correctly.
Table of Contents
Here is a comprehensive guide to the options available with the tset command in Linux −
Syntax of tset Command
The syntax of the tset command in Linux is as follows −
tset [options] [terminal]
In the above syntax, the [options] field is used to specify flags that modify how tset behaves. The [terminal] argument is an optional argument used to manually specify the terminal type.
Options of tset Command
The options for the Linux tset command are listed below −
| Option | Description |
|---|---|
| -c | Set control characters and modes. |
| -e ch | Set the erase character to ch. |
| -I | Do not send terminal or tab initialization strings. |
| -i ch | Set the interrupt character to ch. |
| -k ch | Set the line kill character to ch. |
| -m mapping | Map a port type to a terminal. |
| -Q | Suppress display of erase, interrupt, and line kill characters. |
| -q | Print the terminal type without initializing it. |
| -r | Print terminal type to standard error. |
| -s | Print shell commands to set TERM. |
| -V | Display the ncurses version used and exit. |
| -w | Resize the window based on setupterm detection. |
Using tset Command in Linux
This section explores how to use the tset command in Linux with examples −
Initializing a Terminal
To initialize a terminal using the current TERM environment variable, use the tset command without any options −
tset
Setting Terminal Type and Modes
To set the terminal type manually and configure the terminal settings, use the tset command followed by the terminal type −
tset vt100
Note that the tset command by itself does not change $TERM, it just sets terminal modes and optionally prints the terminal type. To update $TERM, it must be done using the following command −
export TERM=vt100
Displaying Shell Command to Set the Terminal Type
To display the shell command to set the terminal type or $TERM, use the -s option −
tset -s
Displaying Terminal Type to Standard Error
To display the terminal type to standard error, use the -r option −
tset -r
Setting the Erase Character
The erase character is a special control character used in the terminal to delete the last typed character; essentially, it acts like a backspace. To set the erase character, use the -e option −
tset -e '^H'
To view the current erase character, use the following command −
stty -a | grep erase
Setting the Interrupt Character
To set the interrupt character, use the -i option −
tset -i '^C'
Pressing this key will stop a running foreground process.
To view the current interrupt character, use the following command −
stty -a | grep intr
Setting the Line Kill Character
To set the line kill character, use the -k option −
tset -k '^K'
Displaying Terminal Type without Initializing
To display the terminal type without initializing, use the -q option −
tset -q
Adjusting the Terminal Window
The -w option adjusts the terminal's size based on the dimensions detected by the setupterm function −
tset -w
The above command adjusts the terminal size according to detected dimensions.
Conclusion
The tset command in Linux helps set up and initialize terminal settings to ensure proper behavior, especially in scripts or login sessions. It allows configuration of special control characters like erase, interrupt, and line kill, and offers various options for customizing terminal initialization. The tset command can also detect and display terminal types, map terminal settings, and resize terminal windows.