Is it possible to prevent subprocess.popen from showing prompts in the terminal?
Attempting to map a drive but would like to read the prompt for credentials in the script rather than display them to the terminal. The idea being I can carry out actions based on the response.
I am aware the use of shell is frowned upon when using string based commands (for obvious reasons), however I'm controlling the input so am happy with the risk for testing purposes.
I was under the impression that all stdout (interaction) would be parsed into the output_null variable. Instead I am still getting the prompt in the terminal (as illustrated below). I'm either miss understanding how the streams work or I'm missing something. Can anyone enlighten me please
command = "mount -t smbfs //{s}/SYSVOL {m}".format(s=server, m=temp_dir)
p = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
output_null = p.communicate()[0]
if "Password for" in output_null:
print 'awdaa'
Terminal Shows
Password for 192.168.1.111:
Related
I’m looking for a C/C++ way to execute a shell command and store the output of that command in a std::string or file, without the output being automatically printed to the console.
All approaches I’ve seen can do exactly that, but also print the execution result to the console.
For example with a combination of
FILE* pipe = popen("ls", "r");
and
fgets()
I’m able to do just that, but with the printing to the console.
Is there perhaps a way to redirect the stream’s buffer from std::cout to std::sstream, or has it semething to do with Ubuntu?
Any help is appreciated :)
The 2>&1 part from the comments did it.
Here's the context:
I am using python 2.7.5. And I would like to run UNIX commands as well as maven commands in a python script.
I was successful to do so, using os.system("cmd"), but I need to work on the result of the given command. After reading the doc and some threads in here, I decided to use the subprocess module to redirect the output to the stdout using PIPE. Unexpectedly, I am getting an OSError as shown in the attached image. Your help will be much appreciated.
In addition to the given sample in the attached image, I have tried:
p = os.popen("java -version")
result = subprocess.check_output(p, shell=True)
subprocess.call("ls /usr", shell=True)
p.s. Using shell=True is strongly discouraged (doc), since it can be dangerous when coupled with unsanitized input.
Also, I took a look at the given script in the error message /usr/lib64/python2.7/subprocess.py, line 711 adn 1327 but didn't learn more than what is mentionned in the error message: raise child_exception
Subprocess Terminal Output
You aren't using subprocess.check_output correctly. You're trying to pass a pipe file object (the return value of os.popen) to check_output but it's expecting a command argument or argument vector.
Also, the subprocess.call function won't capture the executed command's output, so you would only use that if you want the output of ls /usr (or whatever) to be seen by the user running the script interactively. (Which is pretty much the same as os.system.)
Try this instead (showing with and without the shell):
import subprocess
out1a = subprocess.check_output(['java', '-version'], stderr=subprocess.STDOUT)
print(out1a)
out1b = subprocess.check_output('java -version', stderr=subprocess.STDOUT, shell=True)
print(out1b)
out2a = subprocess.check_output(['ls', '/usr'])
print(out2a)
out2b = subprocess.check_output('ls /usr', shell=True)
print(out2b)
# Cannot capture output this way, but it will be visible to user
subprocess.call('ls /usr', shell=True)
Note that in the case of the java -version command, the version info gets printed to the command's standard error output so you must redirect that in order to capture it as the returned value of check_output (hence the stderr=subprocess.STDOUT).
I have a c++ program that run a command and pass some arguments to it. The code is as follow:
int RunApplication(fs::path applicationPathName,std::string arguments)
{
std::string applicationShortPath=GetShortFileName(applicationPathName);
std::string cmd="\""+applicationShortPath +"\" "+ arguments+" >>log.txt 2>&1 \"";
std::cout<<cmd<<std::endl;
int result=std::system(cmd.c_str());
return result;
}
When I run system command, the cmd window appears shortly and then closes, but the result is 1 and the cmd was not run (the command should generate output which is not generated).
To check that the cmd is correct, I stopped the application just before system line and copy/ paste cmd content to a cmd window and it worked.
I am wondering how can I find why application is not run in system()?
the cmd has this value just before running it:
"D:/DEVELO~3/x64/Debug/enfuse.exe" -w --hard-mask --exposure-weight=1 --saturation-weight=0.328 --contrast-weight=0.164 -o "C:/Users/m/AppData/Local/Temp/1.tif" "C:/Users/m/AppData/Local/Temp/1.jpg" "C:/Users/m/AppData/Local/Temp/2.jpg" >>log.txt 2>&1 "
How can I find why it is not working?
Is there any way that I set the system so it doesn't close cmd window so I can inspect it?
is there any better way to run a command on OS?
Does Boost has any solution for this?
Edit
After running it with cmd /k, I get this error message:
The input line is too long.
How can I fix it other than reducing cmd line?
There are two different things here: if you have to start a suprocess, "system" is not the best way of doing it (better to use the proper API, like CreateProcess, or a multiplatform wrapper, but avoid to go through the command interpreter, to avoid to open to potential malware injection).
But in this case system() is probably the right way to go since you in fact need the command interpreter (you cannot manage things like >>log.txt 2>&1 with only a process creation.)
The problem looks like a failure in the called program: may be the path is not correct or some of the files it has to work with are not existent or accessible with appropriate-permission and so on.
One of the firt thing to do: open a command prompt and paste the string you posted, in there. Does it run? Does it say something about any error?
Another thing to check is how escape sequence are used in C++ literals: to get a '\', you need '\\' since the first is the escape for the second (like \n, or \t etc.). Although it seems not the case, here, it is one of the most common mistakes.
Use cmd /k to keep the terminal: http://ss64.com/nt/cmd.html
Or just spawn cmd.exe instead and inspect the environment, permissions, etc. You can manually paste that command to see whether it would work from that shell. If it does, you know that paths, permssions and environment are ok, so you have some other issue on your hands (argument escaping, character encoding issues)
Check here How to execute a command and get output of command within C++ using POSIX?
Boost.Process is not official yet http://www.highscore.de/boost/process/
I am trying to read the output of an executable (A) which is written in c++ from my python script. I am working in Linux. The only way I have known so far is through the subprocess library
Firstly I tried
p = Popen(['executable', '-arg_flag1', arg1 ...], stdout=PIPE, stdin=PIPE, stderr=STDOUT)
print "reach here"
stdout_output = p.communicate()[0]
print stdout_output
sys.stdin.read(1)
which turned out to hang up both my executable (with 99% cpu usage) and my script :S:S:S
Moreover reach here is printed.
After that I tried:
f = open ("out.txt", 'r+')
command = 'executable -arg_flag1 arg1 ... '
subprocess.call(command, shell=True, stdout=f)
f.seek(0)
content = f.read()
and this works but I get an output where some chars at the end of the content are repeated or even more values produced than expected :S
Anyway could someone enlighten me of a more proper way to do this?
Thanks in advance
The first solution is best. Using shell=True is slower, and has security issues.
The problem is Popen doesn't wait for the process to complete, so Python stops leaving the process without stdout, stdin and stderr. Causing that process to go wild. Adding p.wait() should do the trick!
Also, using communicate is a loss of time. Just do stdout_output = p.stdout.read(). You'll have to check yourself if stdout_output contains anything though, but this is still nicer than using communicate()[0].
I have a quick question, should be relatively simple for those who have some more experience in WMI-command processor than I do (and since I'm an absolute beginner thats not hard :-) )
I fail to understand why wmic /format switch works the way it does. I open up cmd.exe and type
wmic process list brief /format:htable > processlist.html
this does exactly what I want and no bothers further on. Whereas if I go to wmic processor, and try to execute the same command exactly as above...
wmic:root\cli>process list brief /format:htable > processlist.html
I receive the error tag: "Invalid XSL format (or) file name."
Here goes the screenshot. Note I have already copied XSL files from wbem to sys32 dir
Can someone explain to me why these 2 commands that for me look exactly the same, with the only difference that one is executed outside wmic environment and the other one is from inside, the latter one doesn't work? I just fail to understand it.
Please advise so I can comprehend this a bit better! :-)
Try this
copy /y %WINDIR%\system32\wbem\en-US\*.xsl %WINDIR%\system32\
And then
wmic:root\cli>process list brief /format:htable.xsl > processlist.html
Note the presence of the extension after "htable"
You are attempting to use CMD.EXE > redirection while you are within the interactive WMIC context. That can't work.
You can use the WMIC /output:filename switch while in interactive mode. Each subsequent command will overwrite the output of the previous command. You can get multiple commands to go to the same file by using /append:filename instead. You can reset the output back to stdout using /output:stdout.
/output:processlist.html
process list brief /format:htable
/output:stdout
Did you try specifying a full path in the wmic:root\cli>process call? My bets are that the first worked because it output the file to the current directory.