I am trying to run the following subprocess.Popen() command in python 2.6
output = subprocess.Popen("psexec -accepteula \\machineName -u username -p password cmd.exe /C fsutil fsinfo drives", stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
print(output.communicate())
But I get the following result with output.communicate()
('\r\n', '\r\nPsExec v2.11 - Execute processes remotely\r\nCopyright (C) 2001-2014 Mark Russinovich\r\nSysinternals - www.sysinternals.com\r\n\r\nConnecting to machineNameHere...\r\r\rStarting PSEXESVC service on machineNameHere...\r\r\rConnecting with PsExec service on machineNameHere...\r\r\rStarting cmd.exe on machineNameHere...\r\r\r\r\ncmd.exe exited on machineNameHere with error code 0.\r\n')
When I run the same psexec command from cmd line in windows, I get the correct output.
PsExec v2.11 - Execute processes remotely
Copyright (C) 2001-2014 Mark Russinovich
Sysinternals - www.sysinternals.com
**Drives: A:\ C:\ D:\**
cmd.exe exited on machineNameHere with error code 0.
I am looking for the output **Drives: A:\ C:\ D:** even while running the psexec command using subprocess.Popen(). Any way I can do it?
Now I narrowed down the issue by running different commands like dir and echo "test". The issue seems to be that Popen is reading only first line into stdout and not the complete output. Any suggestions on how to fix this?
(expanding on John Gordon's comment on the question)
you are trying to run this command through a shell:
"psexec -accepteula \\machineName -u username -p password cmd.exe /C fsutil fsinfo drives"
notice that you have double backslashes within the command (\\machineName). The backslash happens to be an escape character in string literals (used to escape characters that otherwise have a special meaning). Therefore, \\machineName is getting translated to \machineName before it is passed to the spawned process.
here are 2 ways to handle this:
1) prepend an escape character (another backslash) before each backslash:
"psexec -accepteula \\\\machineName"
2) add an 'r' before the string literal, which makes it a a raw string, and will not interpret the backlsashes as escape chars:
r"psexec -accepteula \\machineName"
Here is an example in the python interpreter that should make it clear. Notice the output that gets printed:
>>> print("\\machineName")
\machineName
>>> print("\\\\machineName")
\\machineName
>>> print(r"\\machineName")
\\machineName
Related
I have a script where I need to start a command, then pass some additional commands as commands to that command. I tried
su
echo I should be root now:
who am I
exit
echo done.
... but it doesn't work: The su succeeds, but then the command prompt is just staring at me. If I type exit at the prompt, the echo and who am i etc start executing! And the echo done. doesn't get executed at all.
Similarly, I need for this to work over ssh:
ssh remotehost
# this should run under my account on remotehost
su
## this should run as root on remotehost
whoami
exit
## back
exit
# back
How do I solve this?
I am looking for answers which solve this in a general fashion, and which are not specific to su or ssh in particular. The intent is for this question to become a canonical for this particular pattern.
Adding to tripleee's answer:
It is important to remember that the section of the script formatted as a here-document for another shell is executed in a different shell with its own environment (and maybe even on a different machine).
If that block of your script contains parameter expansion, command substitution, and/or arithmetic expansion, then you must use the here-document facility of the shell slightly differently, depending on where you want those expansions to be performed.
1. All expansions must be performed within the scope of the parent shell.
Then the delimiter of the here document must be unquoted.
command <<DELIMITER
...
DELIMITER
Example:
#!/bin/bash
a=0
mylogin=$(whoami)
sudo sh <<END
a=1
mylogin=$(whoami)
echo a=$a
echo mylogin=$mylogin
END
echo a=$a
echo mylogin=$mylogin
Output:
a=0
mylogin=leon
a=0
mylogin=leon
2. All expansions must be performed within the scope of the child shell.
Then the delimiter of the here document must be quoted.
command <<'DELIMITER'
...
DELIMITER
Example:
#!/bin/bash
a=0
mylogin=$(whoami)
sudo sh <<'END'
a=1
mylogin=$(whoami)
echo a=$a
echo mylogin=$mylogin
END
echo a=$a
echo mylogin=$mylogin
Output:
a=1
mylogin=root
a=0
mylogin=leon
3. Some expansions must be performed in the child shell, some - in the parent.
Then the delimiter of the here document must be unquoted and you must escape those expansion expressions that must be performed in the child shell.
Example:
#!/bin/bash
a=0
mylogin=$(whoami)
sudo sh <<END
a=1
mylogin=\$(whoami)
echo a=$a
echo mylogin=\$mylogin
END
echo a=$a
echo mylogin=$mylogin
Output:
a=0
mylogin=root
a=0
mylogin=leon
A shell script is a sequence of commands. The shell will read the script file, and execute those commands one after the other.
In the usual case, there are no surprises here; but a frequent beginner error is assuming that some commands will take over from the shell, and start executing the following commands in the script file instead of the shell which is currently running this script. But that's not how it works.
Basically, scripts work exactly like interactive commands, but how exactly they work needs to be properly understood. Interactively, the shell reads a command (from standard input), runs that command (with input from standard input), and when it's done, it reads another command (from standard input).
Now, when executing a script, standard input is still the terminal (unless you used a redirection) but the commands are read from the script file, not from standard input. (The opposite would be very cumbersome indeed - any read would consume the next line of the script, cat would slurp all the rest of the script, and there would be no way to interact with it!) The script file only contains commands for the shell instance which executes it (though you can of course still use a here document etc to embed inputs as command arguments).
In other words, these "misunderstood" commands (su, ssh, sh, sudo, bash etc) when run alone (without arguments) will start an interactive shell, and in an interactive session, that's obviously fine; but when run from a script, that's very often not what you want.
All of these commands have ways to accept commands by ways other than in an interactive terminal session. Typically, each command supports a way to pass it commands as options or arguments:
su root -c 'who am i'
ssh user#remote uname -a
sh -c 'who am i; echo success'
Many of these commands will also accept commands on standard input:
printf 'uname -a; who am i; uptime' | su
printf 'uname -a; who am i; uptime' | ssh user#remote
printf 'uname -a; who am i; uptime' | sh
which also conveniently allows you to use here documents:
ssh user#remote <<'____HERE'
uname -a
who am i
uptime
____HERE
sh <<'____HERE'
uname -a
who am i
uptime
____HERE
For commands which accept a single command argument, that command can be sh or bash with multiple commands:
sudo sh -c 'uname -a; who am i; uptime'
As an aside, you generally don't need an explicit exit because the command will terminate anyway when it has executed the script (sequence of commands) you passed in for execution.
If you want a generic solution which will work for any kind of program, you can use the expect command.
Extract from the manual page:
Expect is a program that "talks" to other interactive programs according to a script. Following the script, Expect knows what can be expected from a program and what the correct response should be. An interpreted language provides branching and high-level control structures to direct the dialogue. In addition, the user can take control and interact directly when desired, afterward returning control to the script.
Here is a working example using expect:
set timeout 60
spawn sudo su -
expect "*?assword" { send "*secretpassword*\r" }
send_user "I should be root now:"
expect "#" { send "whoami\r" }
expect "#" { send "exit\r" }
send_user "Done.\n"
exit
The script can then be launched with a simple command:
$ expect -f custom.script
You can view a full example in the following page: http://www.journaldev.com/1405/expect-script-example-for-ssh-and-su-login-and-running-commands
Note: The answer proposed by #tripleee would only work if standard input could be read once at the start of the command, or if a tty had been allocated, and won't work for any interactive program.
Example of errors if you use a pipe
echo "su whoami" |ssh remotehost
--> su: must be run from a terminal
echo "sudo whoami" |ssh remotehost
--> sudo: no tty present and no askpass program specified
In SSH, you might force a TTY allocation with multiple -t parameters, but when sudo will ask for the password, it will fail.
Without the use of a program like expect any call to a function/program which might get information from stdin will make the next command fail:
ssh use#host <<'____HERE'
echo "Enter your name:"
read name
echo "ok."
____HERE
--> The `echo "ok."` string will be passed to the "read" command
I am trying to open one file from gnome-terminal using python. But I am not able to do it.It is just opening terminal and not opening file.
I have tried like:
import os
os.system('gnome-terminal --working-directory = "folder_path" + "[-e, --command=" kate aaa.txt""')
Can anyone please help?
The problem is + "[-e, --command=" kate aaa.txt"", gnome-terminal doesn't know how to parse this + "[ and "", according to the manual, -e and --command mean the same thing:
man gnome-terminal
...
--command, -e=COMMAND
Split the argument to this option into a program and arguments in the same way a shell
would, and execute the resulting command-line inside the terminal.
This option is deprecated. Instead, use -- to terminate the options, and put the program
and arguments to execute after it: for example, instead of gnome-terminal -e "python3 -q",
prefer to use gnome-terminal -- python3 -q.
Note that the COMMAND is not run via a shell: it is split into words and executed as a
program. If shell syntax is required, use the form gnome-terminal -- sh -c '...'.
This works for me in Archlinux:
import os
os.system('gnome-terminal --working-directory = /home/ramsay --command="kate
os"')
I am aware that many similar questions have been posted here but none of them seems to work in my case. I have a few commands in my bash profile like below
export HEADAS=/Users/heasoft/x86_64-apple-darwin18.7.0
alias heainit=". $HEADAS/headas-init.sh"
. $HEADAS/headas-init.sh
export SAS_DIR=/Users/sas-Darwin-16.7.0-64/xmmsas
alias sas=". $SAS_DIR/setsas.sh"
sit='source ~/.bash_profile'
in which I created an alias to run them consecutively: alias prep1='sit; heainit; sas. This works just fine when I execute it in the command line. But I want to insert in a python script and run it from there. I am running Python (v 3.7.4). So, as suggested in here, I tried
import subprocess
command = "prep1"
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=None, shell=True)
output = process.communicate()
print(output[0].decode())
But I get an error saying command not found. I tried to export it in bash profile but got an error stating -bash: export: prep1: not a function
I also tried the method suggested in here, but still nothing. Related to this, I couldn't even run a shell command like below in python
epatplot set=evli.FTZ plotfile="pn_filtered_pat.ps" 2>&1 | tee pn_filtered_pat.txt
Here is my Python script attempt
command = "epatplot set=evli.FTZ plotfile="pn_filtered_pat.ps" 2>&1 | tee pn_filtered_pat.txt"
process = subprocess.Popen(command.split(), stdout=subprocess.PIPE)
output, error = process.communicate()
I get SyntaxError: invalid syntax. I know where this syntax error is rising from but don't know how to fix.
I am a beginner in python so I appreciate any help/guidance.
Please see this answer: https://askubuntu.com/a/98791/1100014
The recommendation is to convert your aliases to bash functions and then export them with -f to be available in subshells.
When you call Popen, execute "bash -c <functionname>".
As for your last script attempt, you have a conflict in quotation marks. Replace the outer quotes with single quotes like this:
command = 'epatplot set=evli.FTZ plotfile="pn_filtered_pat.ps" 2>&1 | tee pn_filtered_pat.txt'
process = subprocess.Popen(command.split(), stdout=subprocess.PIPE)
output, error = process.communicate()
If I run this command in ubuntu shell:
debconf-set-selections <<< 'postfix postfix/mailname string server.exmaple.com'
It runs successfully, but if I run it via python:
>>> from subprocess import run
>>> run("debconf-set-selections <<< 'postfix postfix/mailname string server.exmaple.com'", shell=True)
/bin/sh: 1: Syntax error: redirection unexpected
CompletedProcess(args="debconf-set-selections <<< 'postfix postfix/mailname string server.exmaple.com'", returncode=2)
I don't understand why python is trying to interpret whether there is redirection etc. How does one make the command successfully run so one can script installation of an application, e.g. postfix in this case via python (not a normal bash script)?
I have tried various forms with double and single quotes (as recommended in other posts), with no success.
subprocess uses /bin/sh as shell, and presumably your system's one does not support here-string (<<<), hence the error.
From subprocess source:
if shell:
# On Android the default shell is at '/system/bin/sh'.
unix_shell = ('/system/bin/sh' if
hasattr(sys, 'getandroidapilevel') else '/bin/sh')
You can run the command as an argument to any shell that supports here string e.g. bash:
run('bash -c "debconf-set-selections <<< \"postfix postfix/mailname string server.exmaple.com\""', shell=True)
Be careful with the quoting.
Or better you can stay POSIX and use echo and pipe to pass via STDIN:
run("echo 'postfix postfix/mailname string server.exmaple.com' | debconf-set-selections", shell=True)
I'm trying to run a python script that will open a command prompt(OSGeo4W.bat is a command prompt line). I can get it to open but now I would like to send the command prompt commands.
import subprocess
myProcess = subprocess.Popen(['C:\OSGeo4W64\OSGeo4W.bat'],shell = False) #opens command prompt
myProcess.communicate('gdal2tiles -p raster -z 0-1 new.jpg abc')
myProcess.wait()
print("my process has terminated")
I've also tried
subprocess.check_call('gdal2tiles -p raster -z 0-1 new.jpg abc', shell=False)
I keep getting errors that say "WindowsError: [Error 2] The system cannot find the file specified"
although, if I were to keep the command prompt that it opens and type in " 'gdal2tiles -p raster -z 0-1 new.jpg abc' " then it will work just as I wanted. Help would be great, thanks!
Try:
check_call('gdal2tiles -p raster -z 0-1 new.jpg abc', shell=True)
shell=True changes how the executable is searched on Windows.
Or if gdal2tiles works only in the environment created by OSGeo4W.bat:
shell = Popen(r'C:\OSGeo4W64\OSGeo4W.bat', stdin=subprocess.PIPE)
shell.communicate('gdal2tiles -p raster -z 0-1 new.jpg abc')
# you don't need shell.wait() here
Notice: r"" literal. It is necessary to avoid escaping the backslashes in the path.
For those of you that are still trying to figure this one out, this is what I found. The "stdin=subprocess.PIPE" method above works with some command line tool in OSGeo4W64 but not all. It works with gdal_translate but not pdal translate for example. Not sure why;(
My Solution:
OSGeo4Wenv = r'CALL "C:/OSGeo4W64/bin/o4w_env.bat" '
pdal_translate_String = r'c:/OSGeo4W64/bin/pdal translate c:\inputFile c:\outputFile radiusoutlier --filters.radiusoutlier.min_neighbors=2 --filters.radiusoutlier.radius=8.0 --filters.radiusoutlier.extract=true'
Cmd = str(OSGeo4Wenv)+' & '+str(pdal_translateCmd)
shell = subprocess.call(Cmd, stdout=None, shell=True)
What is going on?
1) Open shell and set up the OSGeo4W environment by calling "OSGeo4Wenv". This is normally called by the OSGeo4W.bat file. Without this, the command line programs don't know where to look for the libraries.
2) The pdal_translate command is then sent to the dos shell because in Windows, multiple commands can be separated by the "&" symbol. I use the .call method of python 2.7. It has the advantage that it waits for the end of the process. That is nice if you use the multiprocessing map.pool method to launch multiple processes at the same time.
Hope this help others!
Nicolas