execute last output line of previous command in linux - linux

How to execute last output line of previous command in linux bash terminal by shortcut?
For example:
$ tree
The 'tree' is currently not installed. You can install it by running:
sudo apt-get install tree
I want to copy for execution sudo apt-get install tree

If the last line is safe for running, a simple command, and contains no spaces or quotes or anything else the shell would need to parse/understand then this should work (though you need to re-run the first command for this).
$(!! 2>&1 | tail -n 1)
That being said I don't recommend this at all. It is much simpler (and safer and supports more complex commands) if you copy and paste or type it out again.
You cannot get the last line of displayed output though so you do need to re-run the command.
Your terminal might support shortcuts to let you copy and paste text though. GNU screen can do this. I believe rxvt-unicode might support this with perl scripts.

Related

Cli colors disappear when piping into a text file [duplicate]

This question already has answers here:
How to trick an application into thinking its stdout is a terminal, not a pipe
(9 answers)
Closed 5 years ago.
Various bash commands I use -- fancy diffs, build scripts, etc, produce lots of color output.
When I redirect this output to a file, and then cat or less the file later, the colorization is gone -- presumably b/c the act of redirecting the output stripped out the color codes that tell the terminal to change colors.
Is there a way to capture colorized output, including the colorization?
One way to capture colorized output is with the script command. Running script will start a bash session where all of the raw output is captured to a file (named typescript by default).
Redirecting doesn't strip colors, but many commands will detect when they are sending output to a terminal, and will not produce colors by default if not. For example, on Linux ls --color=auto (which is aliased to plain ls in a lot of places) will not produce color codes if outputting to a pipe or file, but ls --color will. Many other tools have similar override flags to get them to save colorized output to a file, but it's all specific to the individual tool.
Even once you have the color codes in a file, to see them you need to use a tool that leaves them intact. less has a -r flag to show file data in "raw" mode; this displays color codes. edit: Slightly newer versions also have a -R flag which is specifically aware of color codes and displays them properly, with better support for things like line wrapping/trimming than raw mode because less can tell which things are control codes and which are actually characters going to the screen.
Inspired by the other answers, I started using script. I had to use -c to get it working though. All other answers, including tee, different script examples did not work for me.
Context:
Ubuntu 16.04
running behavior tests with behave and starting shell command during the test with python's subprocess.check_call()
Solution:
script --flush --quiet --return /tmp/ansible-output.txt --command "my-ansible-command"
Explanation for the switches:
--flush was needed, because otherwise the output is not well live-observable, coming in big chunks
--quiet supresses the own output of the script tool
-c, --command directly provides the command to execute, piping from my command to script did not work for me (no colors)
--return to make script propagate the exit code of my command so I know if my command has failed
I found that using script to preserve colors when piping to less doesn't really work (less is all messed up and on exit, bash is all messed up) because less is interactive. script seems to really mess up input coming from stdin even after exiting.
So instead of running:
script -q /dev/null cargo build | less -R
I redirect /dev/null to it before piping to less:
script -q /dev/null cargo build < /dev/null | less -R
So now script doesn't mess with stdin and gets me exactly what I want. It's the equivalent of command | less but it preserves colors while also continuing to read new content appended to the file (other methods I tried wouldn't do that).
some programs remove colorization when they realize the output is not a TTY (i.e. when you redirect them into another program). You can tell some of those to use color forcefully, and tell the pager to turn on colorization, for example use less -R
This question over on superuser helped me when my other answer (involving tee) didn't work. It involves using unbuffer to make the command think it's running from a shell.
I installed it using sudo apt install expect tcl rather than sudo apt-get install expect-dev.
I needed to use this method when redirecting the output of apt, ironically.
I use tee: pipe the command's output to teefilename and it'll keep the colour. And if you don't want to see the output on the screen (which is what tee is for: showing and redirecting output at the same time) then just send the output of tee to /dev/null:
command| teefilename> /dev/null

Recursively adding bash scripts as commands in Linux?

I'm pretty new to Bash and Linux in general. I've created a couple scripts that I would like to be able to use by typing the command, rather than the directory and the executable file. I'm using Debian Jessie if that makes a difference.
The path to one of my scripts is ~/Scripts/DIR_1/My_Script.sh while another is in ~Scripts/DIR_2/My_Other_Script.sh. I would like ALL of the scripts contained withing the Scripts directory to be indexed as commands regardless of directory/path depth.
I've appended this text to the end of my .bashrc file...
PATH=${PATH}:$(find ~/Scripts -type d | sed '/\/\\./d' | tr '\n' ':' | sed 's/:$//')
Since I'm pretty new to this kind of thing, I had to steal that line from here.
When I try to run My_Script from the command line withing a sub directory of my home folder (or anywhere else for that matter) I get My_Script: command not found
I will readily admit that I might have misunderstood the process of adding a bash script to the command line.
How do I recursively add bash scripts as commands? What is wrong with the process I'm currently using?
I think your issue is that you're not putting the .sh, that is part of your file name.
Normally, pressing tab after having typed only the first letter should complete the command up to the point where there is an ambiguity (or completely if there's none). In case of ambiguity, pressing tab a second time shows the options. So in your case, if you type My<tab><tab> you should have options My_Script.sh and My_Other_Script.sh displayed. And if you type My_Script<tab> it should complete by putting My_Script.sh
Edit
I forgot to precise that you can check the value of PATH by doing echo $PATH. This will allow you to check that the command you copied did what you wanted.

Can linux or mac terminal commands scroll up instead of down?

I'm wondering if there is a way set a linux or mac terminal so that you are always entering commands at the top of the terminal screen, and previous commands are below it.
Example
-----Screen top----
>EnterCommand
>PreviousCommand 1
>final line of Previous Command 1 output
>second to final line of previous command 1 output
-----Bottom of screen-----
Thanks!
Such a feature is not built into the standard *nix terminal driver; a terminal application would have to be specifically written to translate newlines and line wrapping into upward motion instead of downward. Note that this will likely break a number of TUI applications, so it is not recommended to use them with such a terminal application.
This seems pretty close to what you're asking for:
https://github.com/swirepe/alwaysontop
To use it run:
git clone https://github.com/swirepe/alwaysontop.git
cd alwaysontop/
source alwaysontop.sh
If you decide you like it just source it in your .bashrc or .bash_profile with something like:
echo "source ~/alwaysontop/alwaysontop.sh" >> ~/.bashrc
Hope that helps!

store all the data in terminal to text file by tee command or equivalent tool

I learnt that a tee command will store the STDOUT to a file as well as outputs to terminal.
But, here the problem is every time I have to give tee command, for every command I give.
Is there any way or tool in linux, so that what ever I run in terminal, it should store the command as well as output. (I used tee command in MySQL, where it will store all the commands and outputs to a file of that entire session. I am expecting a tool similar to this.)
Edit:
When I run script -a log.txt, I see ^M characters as well as ^[ and ^] characters in log.txt file. I used various dos2unix, :set ff=unix, :set ff=dos commands, but they didn't helped me in removing these ^[, ^] characters.
Is there any method, I can directly get the plain text file (with out these extra chars).
OS: RHEL 5
You can use script command which writes everything on file
script -f log.txt
you could use aliases like such alias ls="ls;echo ls >>log" so every time you run ls it runs echo ls >>log too.
But script would probably be better in this case, just dont go into vi while you are in script.

Linux command to DOS

I have a file include some linux command and I want to run in on windows (DOS command).
The command is:
cat tmp/$id/index.html | sed -e 's/ID/$id/g' > a;mv a tmp/$id/index.html
What is the similar command in MS-DOS?
Thank you!
The problem is that natively there is no equivalent command to sed. You have two options from my point of view. Either create a vb script that does what you want (It will not take 1 line though - more like 10-15 I guess), or use something like GnuWin32 that gives you the option to run unix commands in windows terminal.
You could consider using powershell to do approximately the same thing. It supports cat and mv and you can get a sed like equivalent by using %{_ -replace "expression", "replace"}. Details here http://blogs.msdn.com/b/zainnab/archive/2007/07/09/grep-and-sed-with-powershell.aspx
Or consider using a linux like command prompt like bash which should be available through cygwin
I think this is impossible to do in "bare" command line (as you called DOS command), because cat and sed are separate utilities. If you want to port this script from Linux command shell to windows command line, I would advise you to download and install CygWin
DOS itself does not have support for that. You could try with a port of SED for DOS available here. If you can get Powershell, that's an option. Here's an example of using grep/sed with Powershell.
There are many options.
You can try to install cygwin or download and install Git and use Git-bash or add the bin directory to your PATH so you can run this command on your CMD prompt.
There is no such command(s) for MS-DOS.

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