I catted a binary file and hit Ctrl-Z to stop it. Now ls results are misaligned. What did it happen and how could I have them listed correctly again ?
Type reset to reset your terminal, and press Enter. Then maybe press Ctrl+L to clear the screen. You should be back to normal.
Oh and by the way, that binary cat you ran, when you pressed Ctrl-Z that just suspended it, it's probably still running. Run jobs to see the list of jobs, and if it's there, say job number 2, do kill %2 (or whichever job number).
When you catted the binary file, your terminal probably inadvertently interpreted some of its data as control sequences and tried to execute them, screwing its properties and state.
You can either kill the terminal altogether (quit it if you're in a GUI, or relog if you're on a tty), or use another control sequence to reset the terminal. echo -e \\033c should do the trick. Some systems also have a reset builtin/command, which accomplishes the same thing.
Related
Often when I run a command that writes to stdout, and that command fails, I have to scroll up (using uncomfortable key-bindings) looking for the place where I pressed Enter, to see what the first error was (out of hundreds others, across many screens of text). This is both annoying and time-consuming. I wish there was a feature which allowed me to pin my current terminal to the place where I am now, then start the command, see only the first lines of the output (as many as fits below my cursor) and let the rest of the output be written but not displayed. In other words I would like a feature to allow me automatically scroll up to the place where I gave the command, to see the first lines of the output (where usually the origin of the failure is displayed).
I searched for it but I didn't find it. Do you know if such feature exists? Or have an idea how to implement it with some tricks or workarounds?
If you have a unique shell prompt you could bind a key to jump between shell prompts, for example something like this will make C-b S jump to the previous shell prompt then S subsequent ones:
bind S copy-mode \; send -X search-backward 'nicholas#myhost:'
bind -Tcopy-mode S send -X search-backward 'nicholas#myhost:'
Or similarly you could search for error strings if they have a recognisable prefix. If you install the tmux 3.1 release candidate, you can search for regular expressions.
Alternatively, you could use capture-pane to load the entire history into an editor with key bindings you prefer, for example:
$ tmux capturep -S- -E- -p|vim -
Or pipe to grep or whatever. Note you will need to use a temporary file for this to work with emacs.
Or try to get into the habit of teeing commands with lots of output to a file to start with.
I have been driven crazy for years with Vim's behavior of throwing away input characters. I start vim like this:
$ vim file.c
and then immediately begin typing commands. However, Vim discards some of those characters, causing the wrong action to take place.
Is there something we can put in the .vimrc to solve this issue?
Vim should be able to change the TTY to raw mode without flushing buffered input.
Update: the issue is more precisely characterized, thanks to the following investigation method. I created a script called delayvim which contains:
#!/bin/sh
sleep 2.0
vim "$#"
Now during this two second pause I can type something like iabc<ESC> and then when Vim comes up, everything is cool: the command is processed, abc is inserted and Vim pops back into command mode, with the cursor backed up over the c. Thus, it is not simply flushing the TTY input buffer.
However, if I keep typing during this delay, for instance iabcdefghijk..., it will sometimes lose a letter or two of the alphabet that is typed right around the time when the sleep terminates and the editor launches. For instance, here is the result of one trial I just performed:
abcdefghilmn_
~
~
Where are jk, oops? I am sure I typed them. I didn't type very fast; my cadence was around 4-5 strokes per second, yet two consecutive events disappeared.
Basically, it might be trying to interrogate the terminal, and in the process discarding the input that is mixed up in the response. Or it could be a combination of reading some of the prior input, then flushing the input buffer and losing the rest.
2 points that might help:
1) are you being sure to hit i first, to enter input mode, so that all characters you type afterward should go ahead and be seen in your buffer (on the screen?). Otherwise the letters you type will be processed as commands, which will often do nothing, especially if you're starting an empty file.
Note that a and o are other common commands for telling vim that you are about to begin inserting text starting with the next keystroke.
2) In case the reason on your system has to do with speed, you can look for options to change what happens at startup. For example, if you put this in your .vimrc file
autocmd VimEnter * :sleep 5
Then after processing other startup files, vim or gvim will literally do nothing for 5 seconds before showing your file on the screen. On my system, I was able to type iabcdef during those 5 seconds and when the time was up, I did see abcdef entered into my text file.
If your file was not empty, beware, as (depending on your settings) your vim installation might be kindly returning you to the last place you were editing inside the file, and you will have inserted the text there, instead of at the start.
If this doesn't work, you could try to find other things vim can do (on the web, or using :help from within vim) and program it using autocmd to happen at startup to see if it helps.
After typing this command
less +F file_name.data
I am able to see a file as data is being written to on the fly. This is great but after the data has been fed to the file, I would like to search around the file without leaving the file. Even after all the data has been written to it, it still says at the bottom of the screen "Waiting for data...(interrupt to abort)".
the phrase "Interrupt", to me, means CTRL+C or CTRL+Z but that is not right since I think it will take me out of the file complete. Instead, I think I need to just toggle between modes without leaving the editor. How do I do that?
Normally CTRL-C is trapped by less so that actually you don't quit from less but rather return to the "standard mode". If you don't like this behavior you can run less with -K option in which case less will exit after CTRL-C. By the way, please note that instead of run less +F file you can just hit F in "normal mode".
So to answer your question: you toggle between modes by pressing F and CTRL-C.
Vim has a built-in way for executing programs, namely :!start foo for Windows and :!bar & for Unix. However, the problem I have with those is that they steal focus from Vim. I'd like to launch my build & test script, and while its working and showing output in its command window never have to manually switch back to GVim.
I have thought of 3 possible solutions:
Use Auto-It/AutoHotkey to set focus back to Gvim. Unfortunately that only works in Windows and it's brittle.
Have another process watching my sourcecode, and let that process automatically launch the script when the sourecode changes. (Another process creating a new window does not steal focus). This is a bit gimmicky, as you need to hold off on writing files until you want to start the script, and sometimes write a useless change if you want to re-test even though nothing in the source changed.
Use a client-server architecture, where Vim sends the command over a socket or something similar. This is actually my preferred solution, if there is any existing cross-platform way to do it. (I would prefer not having an extra GVim instance running for this though.)
So what would be a good way to do this? I have tried AsyncCommander but unfortunately it also steals focus.
When I'm not using a nice build system like sbt that watches source code and re-builds/re-tests for me, I tend to come up with hacks like this:
:map <F9> :!touch and-go<CR><CR>
Here hitting F9 updates a file. Pick any key binding you like.
(and of course you could do the same with imap for vim's insert mode as well.)
Then all one needs is a shell script that watches this file and executes the
command that builds/tests your project. On unix, I'd just do:
while stat -c "%Y" and-go; do sleep 1; done |
stdbuf -i0 -o0 uniq -c |
while read l; do
echo build...; # Your build/test execution commands here.
done
Running that in a separate window will be neat, because your vim/gvim window will retain it's focus throughout, while you just keep hitting F9 (or whatever) and glancing at this other window to see how your build went.
If you're up to writing a windows batch script (or powershell, I don't know) version of that as well, you should be good to go.
I think this should work:
:silent! !cmd /c start /b dir
Also, start.exe does have an option to start minimized instead of with the shared/background console.
Of course, dir is to be replaced :)
If I do something like:
$ cat /bin/ls
into my terminal, I understand why I see a bunch of binary data, representing the ls executable. But afterwards, when I get my prompt back, my own keystrokes look crazy. I type "a" and I get a weird diagonal line. I type "b" and I get a degree symbol.
Why does this happen?
Because somewhere in your binary data were some control sequences that your terminal interpreted as requests to, for example, change the character set used to draw. You can restore everything to normal like so:
reset
Just do a copy-paste:
echo -e '\017'
to your bash and characters will return to normal. If you don't run bash, try the following keystrokes:
<Ctrl-V><Ctrl-O><Enter>
and hopefully your terminal's status will return to normal when it complains that it can't find either a <Ctrl-V><Ctrl-O> or a <Ctrl-O> command to run.
<Ctrl-N>, or character 14 —when sent to your terminal— orders to switch to a special graphics mode, where letters and numbers are replaced with symbols. <Ctrl-O>, or character 15, restores things back to normal.
The terminal will try to interpret the binary data thrown at it as control codes, and garble itself up in the process, so you need to sanitize your tty.
Run:
stty sane
And things should be back to normal. Even if the command looks garbled as you type it, the actual characters are being stored correctly, and when you press return the command will be invoked.
You can find more information about the stty command here.
You're getting some control characters piped into the shell that are telling the shell to alter its behavior and print things differently.
VT100 is pretty much the standard command set used for terminal windows, but there are a lot of extensions. Some control character set used, keyboard mapping, etc.
When you send a lot of binary characters to such a terminal, a lot of settings change. Some terminals have options to 'clear' the settings back to default, but in general they simply weren't made for binary data.
VT100 and its successors are what allow Linux to print in color text (such as colored ls listings) in a simple terminal program.
-Adam
If you really must dump binary data to your terminal, you'd have much better luck if you pipe it to a pager like less, which will display it in a slightly more readable format. (You may also be interested in strings and od, both can be useful if you're fiddling around with binary files.)