When I'm typing a command longer than around 20 characters the text disappears and the cursor moves to a different location in the terminal. How do I stop this? I find it difficult to understand what I'm doing when this happens.
Your $PROMPT may have escape sequences in it that should be wrapped in %{...%} to keep them from being counted when zsh calculates the length of the displayed prompt.
There could be an incorrect TERM type, resulting in incorrect cursor positioning. For OS X Terminal.app, this term type works well for most curses-based apps:
$ echo $TERM
xterm-color
It should also work well in xterm.
Does not happen here so I suspect something in your setup probably of zsh.
Have you tried moving all your ~/.zsh* files and start with a blank environment?
Related
Several *NIX commands, such as screen, man, vim and others, create a temporary canvas/screen/overlay in a shell environment. When such programs execute, they cover or hide whatever content was displayed in the terminal before — almost like a "full screen" mode, within the terminal window. When they terminate, however, they reveal or restore whatever had been on the terminal before.
In the example below, I create some filler text on the screen, then invoke man bash. The man page opens up and covers all other characters on the terminal display. When I close the man page, the characters that had been covered up are again shown.
Before
While an example full-screen program is running
After
I would expect that programs writing to stdout/stderr could accomplish the first step (replacing the content of the terminal with program-specific content), but then it would produce a ton of text that I could scroll through, and therefore couldn't do the second step: restoring the contents of the terminal. That means that somehow either the program memorizes the previous contents of the screen and re-outputs them (I doubt it?), or it creates some sort of sub-window within a terminal and something else keeps track of the previous contents of the terminal.
My Question
How can I accomplish that behavior in my own program and/or script?
Perhaps I should use curses/ncurses, tput, termcap/terminfo, or ANSI escape sequences?
Update:
This revised question is essentially the same as https://unix.stackexchange.com/questions/27941/show-output-on-another-screen-and-return-to-normal-when-done. (I hadn't found it when I had written this question despite lots of searching.) The difference is that my question is more general (any language) whereas that question is specific to Bash. The answers to both questions are essentially the same. If it's too similar to a question on another site, feel free to close it here for that reason.
How do these programs accomplish that behavior?
ANSI escape sequences. Try running this script:
#/bin/bash -
tput smcup
echo 'Hello world!'
sleep 3
tput rmcup
Using infocmp, you can see underlying sequences that create this overlaying effect, e.g:
$ infocmp -1 | grep 'rmcup\|smcup'
rmcup=\E[?1049l\E[23;0;0t,
smcup=\E[?1049h\E[22;0;0t,
is this behavior shell-dependent or system-dependent?
None, it depends on whether the terminal emulator supports save/restore operations.
I have a problem that is my backspace works in the terminal but not in Vim. It sent '^?' instead of '^H' and I have been trying to figure it out. I have checked my .bashrc and there is stty erase '^?' to remove the '^?' but somehow it is not working.
I have this in my .vimrc:
set backspace=indent,eol,start
set backspace=2
fixdel
This is how I would normally fix it according to my knowledge but it doesn't work in this case. I'm using xterm on Arch Linux server if that helps, I know there is a bug for xterm but I don't think that's the case. It works in Unix command but not Vim, so just the Vim that isn't working.
Any help is greatly appreciated.
Edit:
Um to clarify, I just want my backspace to delete things. My backspace doesn't delete things right now and it is giving me ^? instead of deleting. The deleting is the same as any other system that is ^H but I want to make backspace to send ^H which is delete not ^?. So instead of having to type ^H to delete, I want to do it with backspace, on MobaXterm there is a function that makes backspace to send ^H. But how do I do that on SSH?
Thanks
There's two ways to go. To the left, you see the control-H character you crave. The path that way seems clear, just a little
echo xterm.vt100.backarrowKey: true >> ~/.Xresources; xrdb ~/.Xresources
followed by either restarting all of your xterms, or pressing control and your primary mouse button on each window to bring up the menu that lets you change it per window; the menu item itself is the second one in the third section, it's right under the 8-bit controls option. That way seems to be viable. Except, beware, there's a trap door under the control-H itself, as then backspace stops working properly everywhere else except bash itself. Of course, you have part of the way out of that maze already, with your stty fu. But I kind of recall running into all sorts of other issues with that path. One of them being that the Linux console also uses ^? instead of ^H, and that's not so easy to change.
Or, the other way is to get vim to be able to do what you're trying for, using ^?. Which I think is just
:map ^V^? x
Note that I mean control-V backspace, not caret V caret question. You would also want to add this to your ~/.vimrc if that does what you need. That having been said, you didn't say exactly where in vim isn't working quite right, so it's possible you're needing a different tweak instead.
I found an annoying bug while coloring the prompt of my Terminal. If I set my prompt to a colored one, such as
export PS1='\e[1;34m[\e[0;31m\D{%Hh%M} \e[0;32m\u\e[0m#\e[0;35m\h\e[0m:\e[0;36m\w\e[1;34m]\e[0m $ '
then it starts to break when I get some size in the input line:
In other words, when my line reaches some limit, it starts over itself! Once I fill the same line again, then it works well, going to the next line.
Have anyone seen this problem, too? Do you have a solution? The problem also happens in iTerm.
This is a duplicate of Mac Terminal.app annoying bug - How to fix it? from StackOverflow. The problem is that you must surround terminal control characters in square brackets \[ … \] so that the bash shell doesn't count them when calculating the length of the command prompt.
Since this is a generic shell/terminal question and not specific to Mac OS X or Terminal, this should probably be migrated to StackOverflow and made a duplicate of the other question. (However, I don't have privilege to do either.)
I'm having some issues with my Cygwin terminal when I run 'less'. 'less' works fine, but when I come out of it, all the screen buffer history of the terminal is lost. Any suggestions?
I'm running Cygwin on WinXP.
Try running as less -X, or set the LESS environment variable to -X.
It has nothing to do with bash. What's being erased is the text displayed by your terminal emulator.
Like other full-screen programs, less saves the terminal state (including any displayed text and the cursor position) when it starts, and restores it on exit.
It does this by printing the strings defined by the smcup and rmcup terminfo entries.
These depend on the value of the $TERM environment variable.
If these strings aren't printed, or if they're configured to something that doesn't save and restore your terminal state, then less will replace whatever was on your screen by the contents of the file you want to view, and then not restore it.
Using the -X option to less (as suggested by the answer you accepted tells less not to print the smcup and rmcup strings -- which I would expect to cause the problem you're trying to solve.
If you want to save and restore your terminal state (which means that the output produced by less will vanish when you quit), you need to make sure that your $TERM environment variable is set to something with proper smcup and rmcup settings. I find that setting it to xterm usually works.
If you're ambitious, you can create your own terminfo entry and use the tic command to "compile" it to the binary format used by the system.
Dawid Ferenczy's answer suggests another possible cause for the problem; it's not something I've ever run into myself.
(Opinions differ widely on whether saving and restoring the terminal state is a good thing. This blog entry was written by someone who intensely dislikes it. Personally, I like it; if I want to run a full-screen command and keep its output visible while I'm doing something else, I just launch it in another window.)
(The original poster hasn't been on the site in about 2½ years, so we shouldn't expect any feedback, but these answers are likely to be useful to others.)
I had the same issue on my new laptop. I have been using Cygwin on the 64bit Windows 7 for a long time and I never experienced this problem. But on the new fresh system (also 64bit Windows 7) the same Cygwin with the same configuration cleared the screen buffer whenever I quit LESS, MAN, VIM etc. And it bothered me very much. Because I'm using Cygwin inside ConEmu terminal emulator, I suspected ConEmu. After a lot of hours comparing everything what potentially could be the cause (environment variables, configurations, software versions etc.), I had a conversation with the ConEmu's author (and he was really great, exemplary support for the free software!). And we finally found the cause.
The only difference (or one of few) was in the display size. The old laptop has a screen resolution of 1366 x 768 pixels, while the new one has 1920 x 1080. And I'm using the whole screen for the terminal window. It's really strange, but if the terminal window height is greater than cca 62 lines, the screen buffer is cleared after quitting the LESS, VIM etc. No matters if Cygwin is executed inside the ConEMu or plain cmd.exe. Making the terminal window smaller solved the problem. Window height of 62 lines seems to be fine for me. Also, with some of greater height values, the LESS process sometimes crashed.
It seems that it's a problem of the Cygwin.
The whole story you can read here.
Maybe it could help somebody. It took me really a lot of time to solve that. While the solution (or rather workaround) is such damn stupid :)
Using Terminal.app on OS X 10.5, often you see the commands get garbled when you do a reverse-search with Bash. Is there some kind of termcap or perhaps a bash shopt command that can fix this? It is very annoying.
Steps to reproduce: Open Terminal.app, reverse-search to a longish command. Hit <ctrl>-E once you've found the command. The cursor goes to the end of the line, but the display doesn't update.
I'm guessing this is some kind of problem with the readline library on OS X. It's more of a problem with updating the cursor position after a search than anything else. Basically, ctrl-a and ctrl-e tend to break the search output.
os x terminal failure image http://involution.com/images/osxterminal.png
In the above, the first part of the command should be displayed, and the cursor should be at the end of the line, but it isn't. You literally can't see what you're editing when this happens.
I was able to set my TERM to xterm instead of xterm-color and it solves the problem. (export TERM=xterm).
You may want to look at this post.
bash-prompt-in-os-x-terminal-broken
I had the same problem and it had to do with the PS1 variable. Let me know if this helps.
If the prompt has colors, then this is an acknowledged bug.
See bug report msg#00019.
I've encountered this bug, and while I don't know how to solve it, you can work around it by pressing <down><up>
Not sure whether this is the problem here, but a very common cause of a messed up screen in bash (with any terminal emulator, not just Terminal.app) is the window being resized.
Bash will read the window size when it starts up, and then assume it hasn't changed. When the window is resized a signal will be sent to whatever app is currently reading from the console. If this isn't bash (because you're running a text editor at the time, perhaps), then bash won't know about it.
Solution in this case is to resize the window again so that bash gets the signal and notices the new size.
I can't reproduce this, hitting either Ctrl+E, Ctrl+A or the arrow keys updates the command line correctly. Are you running 10.5.4? Is it perhaps a bug in earlier versions?
In worst case, you could launch the X server (somewhere under utilities) and launch a real xterm.