问题
Not until midway through a 3 hour build script, I'll remember that I want to see something at the beginning of the output after it's done. At this point I've exceeded the number of lines in my terminal so I can't scroll up to see it (or the beginning is hard to find). Of course I can be better about storing my output, but I've always been curious if this were possible.
In a linux shell, is it possible to return the output of the last command. I realize I could have piped it or sent the output to a file, but my requirement is to retrieve that output after the command has been run.
Using csh, but would hear about any shell.
回答1:
No. The output of a program never passes through the shell's hands. Without redirection, it goes straight to the TTY. With redirection, it goes straight to whatever file or pipe it was directed to. The shell has no idea what the process sent to stdout/stderr.
回答2:
script(1) is exactly what you need:
script
make
exit
vim typescript
The script program will start a new shell and save input and output to the typescript file. When you're done, just close the shell with exit or ^D. If you'd rather not start a new shell but just run your build, you can use: script -c <command>.
回答3:
If running the command again won't change anything, you can use !! to access the top of the history stack to rerun the last command. Doing so in backticks will allow you to use the result.
$> find . -iname fileInUnknownLocationInHierarchy.txt
./something/buried/deep/where/you/dont/want/to/retype/fileInUnknownLocationInHierarchy.txt
$> vim `!!`
回答4:
This could get very messy with certain commands that use cursor addressing. What's the output of your vim session? Or a slightly more sane example: You're downloading a file with wget, and it shows a percentage bar going from 0% to 100%. What's the output of that?
I think you basically want a hardcopy of anything between your current line and the previous prompt. That's not something shell redirection would be a good example for, that's basically something a terminal would do. You could do it manually by copying and pasting in screen, and maybe you could automate it with its exec command. tmux might have something similar, and you can do weird things with the shell mode(s) of Emacs, but that's a rather heavyweight solution. rxvt-unicode has a perl extension…
回答5:
How about using substitution. Like this:
command1
command2
RESULT=`LASTCOMMAND`
echo $RESULT
回答6:
You can see the return code of the last command, at least in bash, with $?.
As far stdout goes, I don't think you can.
回答7:
If you're looking purely for the return code of the last executed command, use echo $?.
This usually helps when you want to find whether your last command executed successfully and you could also mould this into your build script for pass/fail alerts.
回答8:
save output as a variable?
bash: Output=$(ls); echo $Output
回答9:
My be you can use tee command to put the output to STDOUT as well to a file and then use it.
回答10:
This is a function of your terminal. You should focus on creating a setup where you don't have to remember to do anything. One possible solution is to launch "screen" in your login script (which is not so easy to get right) with logging enabled.
回答11:
You can always run the process inside an emacs shell window. It will keep everything.
来源：https://stackoverflow.com/questions/3286594/output-of-last-shell-command