Ubuntu terminal – go to mouse cursor position

terminalUbuntu

I often run my research experiments through my terminal. The command is a very long one, and often I find the need to change a parameter to the call. The problem is that the call line is long, and the parameter is for example in the middle of the line. To replace the parameter I must keep holding the left arrow/right arrow until I reach the point where the parameter is, then delete and rewrite the characters.

Is there a way to navigate the terminal command line using the mouse cursor position? Clicking in the middle of the line doesn't do anything, of course.

Example:

Suppose I have, in the terminal:

~> runThisProgram(a,b,c,d,……,v,w,x,y,z).

Now I want to run it but with X instead of the parameter c. I have to go to the end of that line, keep pressing the left arrow until I reach the c, and then delete and write X. (or, symmetrically, go to the beginning of the line, keep pressing the right arrow until I reach the c and then delete and write X). Is there a command to just point at the 'c' position using my cursor and go there?

Best Answer

You can move word at a time in shell: Alt+B moves cursor one word backward, Alt+F moves one word forward. Alt+D deletes word after cursor. More hotkey combinations for bash are explained in the manual.

Related Solutions

Posix command that moves cursor to specific position in terminal window

As mikeserv explains, POSIX doesn't specify tput cup. POSIX does specify tput but only minimally. That said, tput cup is widely supported!

The standardised way of positioning the cursor is using ANSI escape sequences. To position the cursor you'd use something like

printf "\33[%d;%dH%s" "$Y" "$X" "$CHAR"

which will print $CHAR at line $Y and column $X. A more complete solution would be

printf "\337\33[%d;%dH%s\338" "$Y" "$X" "$CHAR"

which will restore the cursor position.

Shell – Save cursor position and restore it in terminal

Most of the terminals you are likely to use implement escape sequences for saving and restoring the cursor position. Those are the sc (save cursor) and rc (restore cursor) capabilities in the terminal description, which you can use via tput (just like cup):

tput sc
tput cup 50 10
echo some stuff
echo more stuff
tput rc

However, if your program writes enough text to force scrolling, the restored position will still be on the same place on the terminal's screen. It does not move along with the scrolled text.

POSIX, by the way, documents only part of tput because the tool is actually part of another standard, X/Open Curses. That is summarized in the portability section of the manual page.

Back to the question: there are no escape sequences which track the buffer position (accounting for scrolling). To get that, your application would have to keep track of what was sent to the screen. Solving that sort of problem is what the curses library is for. In a plain command-line application, there is not much that you can do.

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