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Run a linux system command as a superuser, using a python script

由 為{幸葍}努か 提交于 2019-11-27 10:57:10
问题 I have got postfix installed on my machine and I am updating virtual_alias on the fly programmatically(using python)(on some action). Once I update the entry in the /etc/postfix/virtual_alias, I am running the command: sudo /usr/sbin/postmap /etc/postfix/virtual_alias 2>>/work/postfix_valias_errorfile But I am getting the error: sudo: sorry, you must have a tty to run sudo I want to run the mentioned sudo command in a non-human way(meaning, I am running this system command from a python

Best practice to run Linux service as a different user

由 元气小坏坏 提交于 2019-11-27 09:59:20
Services default to starting as root at boot time on my RHEL box. If I recall correctly, the same is true for other Linux distros which use the init scripts in /etc/init.d . What do you think is the best way to instead have the processes run as a (static) user of my choosing? The only method I'd arrived at was to use something like: su my_user -c 'daemon my_cmd &>/dev/null &' But this seems a bit untidy... Is there some bit of magic tucked away that provides an easy mechanism to automatically start services as other, non-root users? EDIT: I should have said that the processes I'm starting in

lsof survival guide [closed]

由 血红的双手。 提交于 2019-11-27 08:56:17
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . lsof is an increadibly powerful command-line utility for unix systems. It lists open files, displaying information about them. And since most everything is a file on unix systems, lsof can give sysadmins a ton of useful diagnostic data. What are some of the most common and useful ways of using lsof, and which

How to export a variable in bash

由 馋奶兔 提交于 2019-11-27 06:52:10
问题 I need to set a system environment variable from a bash script that would be available outside of the current scope. So you would normally export environment variables like this: export MY_VAR=/opt/my_var But I need the environment variable to be available at a system level though. Is this possible? 回答1: This is the only way I know to do what you want: In foo.sh, you have: #!/bin/bash echo MYVAR=abc123 And when you want to get the value of the variable, you have to do the following: $ eval "$

How do I daemonize an arbitrary script in unix?

由 女生的网名这么多〃 提交于 2019-11-27 05:48:17
I'd like a daemonizer that can turn an arbitrary, generic script or command into a daemon . There are two common cases I'd like to deal with: I have a script that should run forever. If it ever dies (or on reboot), restart it. Don't let there ever be two copies running at once (detect if a copy is already running and don't launch it in that case). I have a simple script or command line command that I'd like to keep executing repeatedly forever (with a short pause between runs). Again, don't allow two copies of the script to ever be running at once. Of course it's trivial to write a "while(true

Best practice to run Linux service as a different user

由 落花浮王杯 提交于 2019-11-27 04:09:45
问题 Services default to starting as root at boot time on my RHEL box. If I recall correctly, the same is true for other Linux distros which use the init scripts in /etc/init.d . What do you think is the best way to instead have the processes run as a (static) user of my choosing? The only method I'd arrived at was to use something like: su my_user -c 'daemon my_cmd &>/dev/null &' But this seems a bit untidy... Is there some bit of magic tucked away that provides an easy mechanism to automatically

Renaming lots of files in Linux according to a pattern [closed]

由 ℡╲_俬逩灬. 提交于 2019-11-27 02:42:34
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I'm trying to do three things with the mv command, but not sure it's possible? Probably need a script. not sure how to write it. All files are in same folder. 1) Files ending with v9.zip should just be .zip (the v9 removed) 2) Files containing _ should be - 3) Files with Uppercase letter next to a lowercase

How to find out what group a given user has?

由 强颜欢笑 提交于 2019-11-26 23:51:27
问题 In Unix/Linux, how do you find out what group a given user is in via command line? 回答1: groups or groups user 回答2: This one shows the user's uid as well as all the groups (with their gids) they belong to id userid 回答3: On Linux/OS X/Unix to display the groups to which you (or the optionally specified user) belong, use: id -Gn [user] which is equivalent to groups [user] utility which has been obsoleted on Unix. On OS X/Unix, the command id -p [user] is suggested for normal interactive.

Python script to list users and groups

由 眉间皱痕 提交于 2019-11-26 22:24:21
问题 I'm attempting to code a script that outputs each user and their group on their own line like so: user1 group1 user2 group1 user3 group2 ... user10 group6 etc. I'm writing up a script in python for this but was wondering how SO might do this. p.s. Take a whack at it in any language but I'd prefer python. EDIT: I'm working on Linux. Ubuntu 8.10 or CentOS =) 回答1: For *nix, you have the pwd and grp modules. You iterate through pwd.getpwall() to get all users. You look up their group names with

Tracking CPU and Memory usage per process

由 久未见 提交于 2019-11-26 21:23:29
I suspect that one of my applications eats more CPU cycles than I want it to. The problem is - it happens in bursts, and just looking at the task manager doesn't help me as it shows immediate usage only. Is there a way (on Windows) to track the history of CPU & Memory usage for some process. E.g. I will start tracking "firefox", and after an hour or so will see a graph of its CPU & memory usage during that hour. I'm looking for either a ready-made tool or a programmatic way to achieve this. Martin08 Just type perfmon into Start > Run and press enter. When the Performance window is open, click
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