Tagged Questions
4
votes
5answers
59 views
Insert Lines after Multi-Line Regex Match
I've got an XML file I need to append to after a specific set of tags. Basically the file structure looks like this:
<key>servers</key>
<dict>
... Server Details ...
</dict>
...
0
votes
1answer
460 views
How to execute Netscaler commands through a remote machine via SSH connection
I have been trying to execute some NetScaler commands like "bind" & "unbind" through a Linux Box via an SSH Connection.
Now the Problem is, Manually we are able to enter & execute commands on ...
0
votes
0answers
31 views
bash script loses readonly value after first time thru loop
I have a bash script which seems to lose the value of the readonly constant after the first time thru the for-in loop. For example:
#!/bin/bash
readonly DIR="./groups/"
for output in "${array[@]}"
do
...
2
votes
1answer
690 views
Quickly check whether many network hosts are up-and-running
Objective: check if a host is up-and-running on the network,
with a method that can be efficiently parallelized over many hosts.
Emphasis on a QUICK turnaround of the check.
Reason to emphasise ...
2
votes
1answer
30 views
Fetching Remote Windows System Information From Linux Server
I need a script/command that would fetch Windows System Information (Host Name,User Name, Domain, OS Info, Hardware Info, Memory Info, processor Info, etc) by running it on a Linux Server (RHEL 6.5 ...
1
vote
1answer
81 views
How to run java service as a non-root user on CentOs 6
I have a script that starts a Java application as a service on CentOS 6:
#!/bin/sh
# chkconfig: - 80 20
SERVICE_NAME=cn4server
PATH_TO_JAR=/usr/local/share/myserver/cn4server.jar
...
1
vote
3answers
174 views
How to read the file line by line and to print the previous line where the file contains a single token
For example my file is like:
59 6 18 2014 169 7 14 2 7671912 7849744 201 4
60 6 19 2014 170 5 49 2 7671912 7849744 201 5
61 6 20 2014 171 6 8 2 7671912 7849744 201 6
62 6 23 2014 174 5 3 2 7671912 ...
0
votes
1answer
56 views
Is there a way of copying only directories and not files in bash? [closed]
I want to copy only directories from a folder on a remote server to my server. Is that possible?
Here is the code I have so far but it copies files and folders:
scp -rq ...
1
vote
2answers
123 views
Changing user to root when connected to a linux server and copying files
My script is coded in a way that doesn't allow you to connect to a server directly by root. This code basically copies files a server to my computer and it works but I don't have access to many files ...
2
votes
1answer
90 views
How to make a bash script wait till a pendrive is mounted?
I have a bash script which has a line cd /run/media/Username/121C-E137/ this script is triggered as soon as the pen-drive is recognized by the CPU but this line should be executed only after the ...
0
votes
2answers
59 views
Different forms of executing a shell script
There are a few similar questions around that I've already seen, but I've come up with something different.
I'm reading this http://www.tldp.org/LDP/abs/html/invoking.html and I got confused when I ...
2
votes
1answer
49 views
I'm trying to count and print song file names using awk as following
RANK NAME BAND YEAR GENERE DOMESTIC/INTERNATIONAL
206:Reach Out, I'll Be There:The Four Tops:1978:Pop:3/2
207:Bye Bye Love:The Everly Brothers:1950:Classic:3/2
...
2
votes
3answers
372 views
How to put fixed-width, vertically-oriented key-value pairs in a CSV file?
I have a text file with the following type of content:
OPERATION_CONTEXT VMD1HTE1A71_ns:.oc.GJ_OAD2 alarm_object 1130
On director: VMD1HTE1A71_ns:.temip.VMD1HTE1A71_director
AT Fri 18 Oct 2013 ...
1
vote
1answer
39 views
linux if else fails for some IP's
i am using the following code with if then to mount. It works for some IP's, it does not work for some IP's especially for FAILURE statement.
Here is the code
is_mounted() {
mount | grep -qohw ...
3
votes
2answers
140 views
Does cron know that the instance to be scheduled is already running?
I was wondering if we add a job in the crontab e.g. to run every 5 mins and the job does not actually manage to finish in 5 mins, does the cron daemon know that the previous instance is already ...
2
votes
1answer
447 views
Differences between %pre and %post in Kickstart on CentOS?
I have been setting up machines with Kickstart on CentOS and I am unsure about the differences between the %pre and %post sections of the kickstart .cfg file.
The CentOS Documentation for the ...
1
vote
1answer
89 views
how to check if mysql table is used or an application accesses the table in shell script?
A shell script is doing dump for a mysql table, but before dumping the table I want to check if this table is used by any other application. If so, I want to wait and enter in a loop until the ...
1
vote
1answer
17k views
Convenient way to check if system is using systemd or sysvinit in BASH? [duplicate]
I am defining common bash files which I want to use across different distributions. I need a way to check if system is using systemd or sysvinit (/etc/init.d/). I need this so I run appropriate ...
0
votes
2answers
235 views
Using grep to find first two numbers of IP addresses?
I'm trying to figure out how to use grep to pull out only the first two numbers of an IP address in a list. I've got a routine that is isolating the log entires (from Exim) that I need, now I just ...
1
vote
3answers
227 views
What does “FILENAME=$(echo $INFILE | grep -oE ”[^/]+$“) ” mean?
FILENAME=$(echo /root/Source/code/script.sh | grep -oE "[^/]+$")
I know that it would give me the file name from the file path here as script.sh. But can some one please explain me this?
2
votes
2answers
82 views
Using Sed with Regex
I would need to edit the values in a file delimited by colons (:)
I would like to replace the contents of the file by using regular expression.
After a grep to confirm that the item exist in the file ...
5
votes
3answers
1k views
Using notify-send with cron
I am using Arch Linux with KDE/Awesome WM. I am trying to get notify-send to work with cron. I have tried setting DISPLAY/XAUTHORITY variables, and running notify-send with "sudo -u", all without ...
2
votes
0answers
60 views
Automating startup tasks
I have a "morning ritual" that occurs on every boot of my machine: starting up a few browser tabs, starting up skype, starting up terminator and subdividing some screens, etc.
Is there any tool that ...
1
vote
1answer
78 views
Linux - How to open a console and display command results on startup?
I have a Linux server with a screen always displaying the end of a very usefull file.
How could I automatically enter a shell and display the end of this file when the server starts?
I'd like to do ...
1
vote
1answer
91 views
How to script this task?
First of all, I can make basic use of the linux command line, but have slim to none experience with shell scripting.
What I want to do: I have a router running OpenWRT, a destop pc and an Android ...
3
votes
1answer
113 views
Using tcpdump to log blacklisted IPs
I am using tcpdump to log traffic outbound on a network. I would like to be able to log traffic on a host or IP-only basis but then I would like to be able to log large numbers of potentially ...
-1
votes
2answers
179 views
Shell script passing null value while executed as cron job [closed]
We are using the below commands to get pagesapce values and I need to check percent of used pagespace. For this I have used the below code, but when running this script it's passing a null value into ...
-1
votes
2answers
85 views
Make a new sniffer [closed]
How can use the Linux-kernel to supervise what is going on, about the new connections, new ports, connected hosts? Like I will do a new sniffer.
Which files should I monitor to know what is going ...
2
votes
3answers
219 views
Analyzing tricky one liners & having handy list of useful ones
Have seen one liners like below & took a little time to analyse exact use & working of it – something like set the value to later one if it is not set.
export ...
3
votes
1answer
151 views
How can I write a sed script to delete numbers from a line?
Sample File
a.b.gg3d 0000000001 0000000001 y
a.b.112a 0000000000 0000000001 y
a.b.gg3s 0000000001 0000000001 y
a.b.1111 0000000000 0000000001 m
I have a file that includes about three thousand ...
17
votes
8answers
2k views
The most universal scripting language for Linux is?
We are writing scripts for Linux systems, there has been some debate over what would be the most universally Linux present scripting language to use. Bash, SH, Posix? What?
4
votes
4answers
2k views
Capture output of a bash command, parse it and store into different bash variables
Explanation:
I have a small bash script which simply runs any Linux command (e.g. say ifconfig)
The typical output of ifconfig is something like this:
eth0 Link encap:Ethernet HWaddr ...
6
votes
1answer
205 views
Capabilities for a script on Linux
If I want to set a capability (capabilities(7)), such as CAP_NET_BIND_SERVICE, on an executable file and that file is a script, do I have to set the capability (setcap(8)) on the interpreter starting ...
1
vote
3answers
95 views
Confused on user and su in linux
How could I run a script as a specific user (non-root)? As this?
sudo su - john /usr/share/script.pl for user john?
1
vote
1answer
1k views
What does “sudo chown -R hadoop:hadoop hadoop” do?
I saw the following script, posted online, that was used during the hadoop installation process.
sudo tar xzf hadoop-0.20.2.tar.gz
sudo mv hadoop-0.20.2 hadoop
sudo chown -R hadoop:hadoop ...
0
votes
2answers
390 views
sed - replace complex lines in a file using variables
How do I replace a complex line in a file using sed?
For example I want replace a udev rule in /etc/udev/rules.d/70-persistent-net.rules.
This doesn't work:
OLD_RULE='SUBSYSTEM=="net", ...
2
votes
2answers
408 views
Add a suffix string to end of each line? [duplicate]
I have two files:
file01:
line1
line2
line3
file02:
A
B
C
And I want to get
line1 A
line2 B
line3 C
I could possibly write a Perl script but it is better if I don't need to.
I have tried ...
0
votes
1answer
313 views
when to use double quotes with a variable in shell script? [duplicate]
I am in a confusion with what is meant by the double quotes referring to a variable. For example following two scripts gives the same output. What is really meant by the double quotes?
Script1
...
0
votes
2answers
373 views
How to create as many variables as needed from shell script(bash)?
I'm making a script for monitoring some user processes with Upstart but, since its for the company I work for, they asked me to do it generic...how's so?
Well, the number of processes being monitored ...
0
votes
1answer
92 views
Use of .. in Linux scripting and makefiles [closed]
what is the use of .. in linux scripting and in the following makefile?
MODULE =
EQUALIZER = ..
SRCS =
include ${EQUALIZER}/xyz.mak
include ${EQUALIZER}/pqr.mak
1
vote
1answer
477 views
How to clone a read-only portion of /proc file system
The problem with reading /proc file system is that it is not atomic. I tried using a library (procfs in Python) that wishes to read it, but it has glitches about 5% of the time because the process ...
0
votes
2answers
77 views
Executing a program according to the last modified date
I need to write a script which would execute some executables in a directory according to the last modified date. The oldest should run first. How do I do it?
This is what I have done so far
for f ...
1
vote
4answers
1k views
Checking if a file exists in several directories
I've been working on this far too long and need some help.
I need a script that will look at files in a directory and see if it exists in one of several directories.
I need something like this:
for ...
11
votes
1answer
3k views
Making a progressbar with “dialog” from rsync output
I'm looking for a way to filter/redirect rsync output in a manner where it can be fed to the "dialog --gauge" command, so I can get a nice looking progressbar during file sync.
Currently I have only ...
1
vote
2answers
206 views
find total ram memory and swap memory
I need to write a script to find total memory and total swap of several linux server (2000+).
I have one trusted server from where I can login to all these 2000 servers without a password.
When I run ...
2
votes
1answer
234 views
bash scripting add arguments
I have created a script which takes parameters and arguments. I want to insert the --help argument.
I already know how to parse normal arguments with -, but I don't know how to parse the -- ones.
to ...
13
votes
1answer
1k views
Shebang line with `#!/usr/bin/env command --argument` fails on Linux
I've got a simple script:
#!/usr/bin/env ruby --verbose
# script.rb
puts "hi"
On my OSX box, it runs fine:
osx% ./script.rb
hi
However, on my linux box, it throws an error
linux% ./script.rb
...
5
votes
4answers
502 views
Testing, from a script, if audio devices are in silent?
Is there a default program where I can check if my audio devices are in silent?
Edit: By silence, I mean that if there is something playing on that (not just activated or opened)
Something like ...
2
votes
1answer
188 views
Access the Shift-Insert clipboard from script
How do I access the Shift-Insert (paste) clipboard from a script? You can see what I use here.
Edit: A demonstration how it works, with xclip:
echo hello | xclip -selection secondary
xclip -o ...
6
votes
3answers
855 views
Difference between commands in bash script and commands in terminal
Are there any differences between commands that you type into the terminal and commands you include in a script?
