I want to collect and write the CONSOLE output to a file.
Actually, the output need to be displayed on CONSOLE as well.
I tried below code just to get each line buffer of CONSOLE but it's not correct:
while(!feof(stdout))
{
fgets(szReadBuff, sizeof(szReadBuff), stdout);
// Then write szReadBuff to a created file
...
}
Anyone can help me?
A simple way would be to run ./myprogram | tee output.txt from your shell. tee is a utility that allows you to write to both standard output and one or more files.
Related
Context: I have a program (go-sigma-rule-engine by Markus Kont) on my EC2 instance that runs against a logfile and produces some output to screen.
The command used to run this program is ./gsre/go-sigma-rule-engine run --rules-dir ./gsre/rules/ --sigma-input ./logs/exampleLog.json
The program produces output of the form:
INFO[2021-09-22T21:51:06Z] MATCH at offset 0 : [{[] Example Activity Found}]
INFO[2021-09-22T21:51:06Z] All workers exited, waiting on loggers to finish
INFO[2021-09-22T21:51:06Z] Stats logger done
INFO[2021-09-22T21:51:06Z] Done
Goal: I would like to capture this output and store it in a file.
Attempted Solution: I used the redirection operator to capture the output like so:
./gsre/go-sigma-rule-engine run --rules-dir ./gsre/rules/ --sigma-input ./logs/exampleLog.json > output.txt
Problem: The output.txt file is empty and didn't capture the output of the command invoking the rule engine.
Maybe the output you want to capture goes to standard error rather than standard output. Try using 2> instead of > to redirect stderr.
When type a unterminated command in a mongo shell, it will return three dots indicating need more input to complete this command like below:
> db.test.find(
... {
...
I am using nodejs child_process.spawn to create a mongo shell process and listen on its output. I can get the standard and error output from the mongo shell but I can't get the ... output. Below is my nodejs code:
const shell = spawn('mongo', params);
shell
.stdout
.on('data', (data) => {
winston.debug('get output ' + data);
});
shell
.stderr
.on('data', (data) => {
const output = data + '';
winston.error('get error output ', data);
});
I run below code to send command on the shell:
shell.stdin.write('db.test.find(');
I wander why I can't get the ... output on above method. Is it a special output?
EDIT1
I tried to use node-pty and pty.js. They can get the ... output but they mix the input and output data together. It is not possible to separate them.
I also tried to use stdbuf and unbuffer to disable buffer but it still doesn't work.
It seems that nodejs child_process doesn't work well with interactive command.
Your code doesn't include anything that writes to the stdin of your child process so I would be surprised if you got the ellipsis that indicates incomplete command when in fact you don't send any command at all - incomplete or otherwise.
That having been said, many command line utilities behave differently when they discover a real terminal connected to their stdin/stdout. E.g. git log will page the results when you run it directly but not when you pipe the results to some other command like git log | cat so this may also be the case here.
This can also have to do with the buffering - if your stream is line-buffered then you won't see any line that is not ended with a newline right away.
The real question is: do you see the > prompt? Do you send any command to the mongo shell?
Scritping interactive CLI tools can be tricky. E.g. see what I had to do to test a very simple interactive program here:
https://github.com/rsp/rsp-pjc-c01/blob/master/test-z05.sh#L8-L16
I had to create two named pipes, make sure that stdin, stderr and stdout are not buffered, and then use some other tricks to make it work. It is a shell script but it's just to show you an example.
I have a executable binary on Ubuntu 12.04 64bit, which i uploaded to http://te.ngok.in/InitSDX
I am wondering what kind of output/input it is using. I need to log all of its output to a file, but simply running
./InitSDX seed > log.txt
does not populate any text. But when I do
./InitSDX > log.txt
It does show show error, and logged into the file.
Another method, ./InitSDX seed | less show nothing, but ./IniSDX | less, show the error.
Note, simply running ./InitSDX seed outputs some text on screen.
Can anyone please point something here? What/which output stream should I use and how? Thank you.
UPDATE:
I've tried InitSDX seed > log.txt > 2>&1 still put no text to the file.
Most probably ./InitSDK outputs to stderr. You can redirect it to stdout with:
./InitSDK seed > log.txt 2>&1
You can redirect only stderr to file with:
./InitSDK seed 2> error_log.txt
I execute a program which print some texts. I redirect the texts to file by using > but I cannot see any texts on the file. For example, if the program prints "Hello" I can see the result on the shell:
$ ./a.out arg
Hello
But after I redirect I cannot get any message hello on shell as well as the redirected file.
$ ./a.out arg > log.txt
(print nothing)
$ cat log.txt
(print nothing)
I have no idea what's going on. Is there someone who knows what's happening here? Or is there someone who suffered similar situation?
OS: Ubuntu 14.10, x86_64 arch, and the program is really chromium-browser rather than ./a.out. I edited its JavaScript engine (v8, which is included in chromium-browser) and I tried to print some logs with lots of texts. I tried to save it by redirection but it doesn't work.
Surely I checked whether > symbol work or not. It works as expected on other programs like echo, ls, and so on.
$ echo hello > hello.txt
$ cat hello.txt
hello
How can the messages just go away? I think it should be printed on stdout (or stderr) or file. But it just goes away when I use > symbol.
It is somewhat common for programs to check isatty(stdout) and display different output based on whether stdout is connected to a terminal or not. For example, ls will display file names in a tabular format if output is to a terminal, but display them strictly one per line otherwise. It does this to make it easy to parse its output when it's part of a pipeline.
Not having looked at Chrome's source code myself, this is speculation, but it's possible Chrome is performing this sort of check and changing its output based on where stdout is redirected to.
Try to use "2>" which should redirect stderr to file
Or you can also try to use "&>" which should redirect everything (stderr and stdout)
See more at http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-3.html
Is it possible to export output from apachetop to file? Something like this: "apachetop > file", but because apachetop is running "forever", so this command is also running forever. I just need to obtain actual output from this program and handle it in my GTK# application.
Every answer will be very appreciated.
Matej.
This might work:
{ apachetop > file 2>&1 & sleep 1; kill $! ; }
but no guarantees :)
Another way using linux is to find out the /dev/vcsN device that is being used when running the program and reading from that file directly. It contains a copy of the screen data for a given VT; I'm not sure if there is a applicable device for a pty.
Well indirectly apachetop is using the access.log file to get it's data.
Look at
/var/log/apache2/access.log
You'll simply have to parse the file to get the info you're looking for!/var/log/apache2/access.log