A script is a sequence of commands or instructions that are executed by an interpreter program rather than compiled into a standalone executable program.

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Get exit code of command executed by the linux script command

Note this is run on a debian linux environment I have the following sample script called HelloWorld.sh #!/bin/bash echo "Hello World" exit 1 I then run the following command script -c ...
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56 views

Notifying program that X session is shutting down

Ok. I understand X session is a bit vague here so let me clarify what I mean by the phrase. I mean the situation where a person has been presented with a display manger screen ( eg xdm, kdm, gdm, mdm, ...
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2answers
152 views

How do I drop to a shell after exiting a command I started by scripting tmux?

I'm following this tutorial for scripting the creation of tmux windows. tmux new-window t $SESSION:0 -k -n MAIN 'cd ~/main/ && perl -Ilib myapp' sometimes I kill myapp after I've started ...
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6answers
850 views

Delete all files in directories except those whose path are listed in a file

Given the following files: data/A/a.txt data/B/b.pdf ... date/P/whatever.log ... data/Z/z.jpg I would like to delete all files in the data/A/, data/B/, ..., data/Z/ directories except those files ...
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3k views

Advice for managing SSH keys

What is the best practice you have found for managing lots of SSH keypairs? I use SSH to connect to several systems, both at home and at work. I currently have a fairly small, manageable collection ...
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2answers
288 views

Running commands after event based outputs

there are commands like iwevent or tcpdump -n src host x.x.x.x that send to the stdout some lines when something happens. Is there any form of running some command inmmediatly after a ...
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1answer
594 views

Checking mail and running a script without downloading

I'm writing a script to run certain processing activities (mainly moving some data files to another machine where they can backed up), but I only know when to trigger the copy when a mail is delivered ...
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133 views

Run level script - Help

I want the following command to be ran, as soon as system boots. glances -s -P redhat & How to achieve that? I tried writing a run level script which didn't work as expected.
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1answer
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Script ends abruptly with a Terminated message

This is my bash script. All it does is to check whether a service has started and whether some processes are running as expected. It ends abruptly with a Terminated message. I tried debugging it ...
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1answer
134 views

How can I get information about my virtual desktops via the command line?

I'm curious how I can get information such as the dimensions of my desktop, which desktop is currently active, and what labels (if any) are set for my desktop enviornment (DE).
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314 views

Concatenate files in multiple matching subdirectories

I need to concatenate files based upon the name of the subdirectory they are in. The subdirectories sometimes have duplicates and sometimes don't. The file structure looks like this: RootDir 633 ...
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2answers
87 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 ...
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1answer
2k views

How to set firefox homepage from terminal?

I am trying to configure firefox from a script. I have already hit a wall establishing the deafault homepage. Found some old info what does not work anymore: echo ...
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2answers
12k views

Regular expression in bash script

This is my first time bash scripting so I'm probably making an easy mistake. Basically, I'm trying to write a script that gets the groups of a user, and if they are in a certain group, it will log ...
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2answers
664 views

Optimized way to list and delete files

I need to list and delete .php, .xml files. For this I am using find command. To list : find . -type f -name \*.php -print0 To delete : find . -type f -name \*.php -print0 | xargs -0 rm -r As I run ...
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2answers
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How does this find command using “find … -exec sh -c '…' sh {} +” work?

@StephaneChazelas posted the following solution to this Q&A: Having some trouble using “find -exec {} +”. $ find . -iname "*.extension" -exec sh -c ' exec <command> "$@" <additional ...
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2answers
395 views

Sanitize Apache access log files?

We have this code in a shell script that pipes output for Apache to log. declare -a values=( $taintRequestVals ) for item in ${!values[@]} do cat $apacheLog | sed ...
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4answers
90k views

how can I add (subtract, etc.) two numbers with bash?

I can read the numbers and operation in with: echo "First number please" read num1 echo "Second mumber please" read num2 echo "Operation?" read op but then all my attempts to add the numbers fail: ...
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2answers
1k views

How to copy multiple files but keep their extensions the same?

I am looping through a number of files, and $file represents the current file. How can I make copies or renames and keep the extension the same for this current file? e.g. if $file = x.jpg How to ...
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3answers
6k views

How to add Multiple Searches in AWK command

Im trying to search for the files Created in June,July and August months. I used this method ls -lrth|awk '/[Jun][Jul][Aug]/ {print}' but it ain't working. Please help me correct the syntax.
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3answers
297 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 ...
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2answers
90 views

(Ill)Logical statement

I am attempting to make a simple script to flip my computer screen. My first if statement executes perfectly, but after that, thought $istouch is "on", the elif statement block will not execute! I ...
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1answer
159 views

Regular Expressions within a string in AWK using if/then control structure?

PROBLEM I want to specifically use AWK (GAWK, MAWK, whatever) in an AWK script to sum up the values in field 9 for every record that contains "runner__.jpx" (the underscores are placeholders for two ...
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4answers
268 views

Create a duplicate record based on a condition

I need to write a shell script where I have to create a duplicate record based on a condition and then change the value in a column of the new row which will be created. I am trying to create a ...
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2answers
9k views

Bash shell scripting basic question regarding the syntax and basename

Consider the script below: myname=`basename $0`; for i in `ls -A` do if [ $i = $myname ] then echo "Sorry i won't rename myself" else newname=`echo $i |tr a-z A-Z` mv $i $newname fi done ...
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2k views

Maintain (or restore) file permissions when replacing file

I have a command that accepts a file as an argument, modifies the file, then writes it to the file name specified in the second argument. I'll call that program modifyfile. I wanted it to work "in ...
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3answers
3k views

Summing up an array inside of awk?

I have the following piece of code: sum1= sum2= declare -a a echo $temp | awk '{split($0,a,","); name=a[1] ; for(i=2;i<=4;i++) sum1+=a[i] ; for(i=5;i<=7;i++) sum2+=a[i] }' This code is ...
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1answer
168 views

Configure add-to-tranmission-daemon-action in firefox?

How do I configure firefox such that a clicked bittorent link is automatically added to a transmission daemon that runs on a remote machine? The transmission daemon is available via ...
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4answers
4k views

Shell script to validate mount point status in the linux server

I'm in need of a script which should work as below. A script where it would validate if that specific mountpoint is currently mounted on the server. It would search for mountpoint name in /etc/fstab ...
2
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3answers
259 views

Using sed to insert latex commands around headers of a document

I have a documen with headers in ALL CAPS, for example: NAME env - run a program in a modified environment and I want to insert \item[ before the header and ] \hfill \\ after a header ...
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1answer
302 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 ...
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1answer
2k views

How to run a shell command in a server?

I am fairly familiar with computers and web stuff but this is a bit out of my comfort zone. I have a shell script (.sh file) I want to run in a Linux server I have one site hosted (the script is a ...
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1answer
9k views

bash: integer expression expected

I have a file out.csv I have to check if the name inputed by user exists in the file(comma separated) or not. I am taking name using read but while checking for equality I am getting error ...
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177 views

How can I merge multiple lines with spaces (blank line) separating them? [closed]

I'd like to merge the following multiple lines of output so that they form a single line: line 1: ...
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2answers
7k views

How to get volume level from the command line?

I have a text status bar on a tiling window manager and I am using tcl to feed information to it. At the moment I need a command line that output the volume level 0% to 100%. I am using Arch Linux.
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2answers
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Launching an external script with source command

I've been learning shell scripting, by reading good tutorials and reading scripts. I was reading this minecraft init script, and these first lines hit me: if [ -L $0 ] then source `readlink -e ...
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3answers
483 views

how to calculate the average value of the column that have the row ID?

I want to calculate the average value of my data when they have the same ID (in my specific case, the same day but different time in a day). This is meant to calculate the daily average value of my ...
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3answers
294 views

how to run more than one program in a single script?

I have about 6 programs I want to run one after the other. They all are in different directories with their respective data. I would like help with a script that I can use to run each program in a ...
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2answers
184 views

open a file and copy the listed files to another folder

I have a file named file1.txtcontaining file names like below : filea.txt fileb.txt filec.txt I want to copy the files listed in file1.txt to another folder. What is the UNIX command to use? (the ...
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1answer
4k views

Press a html button via shell script?

i am currently trying to write a script to change some parameters on a webpage via a shell script. I can change the values in the textboxes without any problems, but i can't seem to figure out how i ...
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4answers
543 views

Adding values of the column that have the same data ID?

I want to prepare a uniform daily data from a mixed daily and sub-daily data by adding the sub-daily values and producing a uniform daily data. My sample input and desired out put data looks like ...
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2answers
101 views

how to duplicate values of each row under each for n times? [duplicate]

I have daily data which I want to duplicate in to 24 hours data keeping the value the same for the hourly time step. My data looks like: day Value 01/01/2012 2 01/02/2012 3 Then I want the ...
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0answers
1k views

How do I reset a USB device using a script?

I have a USB GSM modem that does not always work property (Huawei E367u-2) Sometimes it gets reset (USB device disconnect/reconnect in logs) and when it comes back up, it has different ttyUSB numbers. ...
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4answers
8k 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 ...
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3answers
197 views

selecting rows that have the same value [closed]

I have a problem in selecting rows that have the same value. My data is too huge to go row by row to do that. I want you guys to let me know scripts that can perform this. My data looks like as ...
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3k views

how to select, copy columns of different file to form new files

I have four files each contain daily station data. file 1: prec file 2: minT file 3: maxT file 4: wind Here prec, minT, maxT and wind are files that store values of prec, minT, maxT and wind for ...
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Does the shebang determine the shell which runs the script?

This may be a silly question, but I ask it still. If I have declared a shebang #!/bin/bash in the beginning of my_shell_script.sh, so do I always have to invoke this script using bash ...
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1answer
502 views

Similar method to /etc/init.d

I have set my script to run using the /etc/init.d method. All works good. The problem is that my script does packet capturing and when it restarts the machine after say the crond is loaded then it ...
6
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1answer
903 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 ...
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2answers
769 views

Why the inconsistency with using cat vs. echo piped to this sed command?

Inspired by this question: sed: N command does not read single line I wanted to understand why there appears to be an inconsistency between the following 2 commands: #1. echo This command produces ...