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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6
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1answer
778 views

Bash is automatically reloading (injecting) updates into a running script upon saving it: Why? Any practical use?

I was writing a bash script, and happened to updated the code (saved the script file to disk) while the script was waiting for some input in a while loop. After I returned to the terminal and ...
3
votes
2answers
443 views

How to write this pseudocode where condition

This question is extension of this question about listing questions of directories. I get a problem that I need to understand the original section of the text. Current output where you see the ...
2
votes
3answers
5k views

How to escape a single quote? [duplicate]

This works fine: sed -i 's# @driver.find_element(:xpath, "//a\[contains(@href,##' temp_spec.rb against a source of @driver.find_element(:xpath, "//a[contains(@href,'change_district')]").click ...
5
votes
2answers
3k views

Privoxy: blocking twitter, facebook and google outside of their domainslr

Related subject: blocking facebook.com outside facebook.com domain This is from default.filter ################################################################################# # # shockwave-flash: ...
4
votes
1answer
7k views

Extract single file from tar to other folder

I've searched for multiple forums for this questions and have seen different answers but so far, nothing have worked yet even from the ones I've seen here. I want to extract a single file from a tar ...
4
votes
5answers
97 views

Count unique associated values in awk (or perl)

I've already found "How to print incremental count of occurrences of unique values in column 1", which is similar to my question, but the answer isn't sufficient for my purposes. First let me just ...
3
votes
1answer
61 views

How variables inside braces are evaluated

I'm new to shell scripting and I came across these expressions ${var:-val} and ${var-val} ${var:+val} and ${var+val} ${var:=val} and ${var=val} so how are they evaluated and what are the ...
3
votes
2answers
123 views

What do i have to consider to write a script that reacts on a keypress?

I know i can read within a script something into a variable, like this: variable = read But i have to press enter in order to submit the value into the variable. What do i have to know in order to ...
-1
votes
3answers
132 views

Find the time of the file received in a particular directory

I have a directory called /home/mydir/test A file will be sent from some other team which lands in this directory. How to find what is the time the file came to this particular directory? ( I need ...
5
votes
6answers
884 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 ...
5
votes
2answers
3k views

How to copy someone's else folders from public.me.com with a wget-like tool?

How can I copy a folder from http://public.me.com/ (a service related to iDisk, or MobileMe) to my local filesystem with a Unix tool (like wget, a command-line non-interactive tool)? The problem is ...
4
votes
2answers
206 views

When is 'if' not necessary?

In some scripts, I've seen if conditional statements written as: if [ some_conditional_statement ]; then # do stuff fi or [ some_conditional_statement ] && #do stuff Is the second ...
4
votes
5answers
2k views

Bash: Parse multi-line into single-line commands

I have to write a Bash script which checks if another Bash script contains a certain command line. Since Bash allows you to split a command line over multiple lines, my script must be able to merge ...
3
votes
2answers
2k views

Zip folder without including path to folder and require only one argument

I'm trying to make a zip function that'll do all the steps I typically do when zipping a file or folder. Say my current directory is ~, and I want to zip a folder named Folder1, whose file path is ~/...
3
votes
3answers
1k views

Difference between sh -x and ./ for script execution

So I have a simple shell script. What is the difference between the two commands in execution? Is there a preferred way? $sh -x foobar.sh OR $ ./foobar.sh I found the script executed slower when ...
3
votes
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 ...
3
votes
4answers
2k views

Print a string including single quotes and other special characters

How can I write this with an AIX script correctly? My requirement is to write this command in test.txt: clock=$(prtconf -s | awk '{print $4,$5}') I tried this command: print 'clock=$(prtconf -s | ...
3
votes
3answers
883 views

Shell Script to move folders containing a specific word

I'm searching for an simple shell script to mv all folders in /var/www/uploads/ that containing Math or Physics in the name to /mnt/Backup/. I've never done something like that before, due to the ...
2
votes
1answer
85 views

Using individual lines from grep outputs

I'm trying to grab lines from grep and sorting them into another command, the command I'm using for grepping atm is as follows (hasn't yet been chopped enough for what I will be using it, but this ...
1
vote
4answers
3k views

How do I delete files with spaces in them in bash script?

this is a three part topic to a two part process that still is not working for me: Objective: to manipulate a filename then delete it the filename has spaces between the words then the dot .ext ...
1
vote
2answers
999 views

Shell Script - how to scp into remote server and download files and protect password

I have a remote server that I need to download Apache logs from. I can manually scp into the server and get the files, but I'd like to put this in crontab. The only way to automate it is to include ...
1
vote
1answer
166 views

Sort aligned columns

I have a program which output looks like this # Status VAL1 VAL2 Description 1 some text 2.5 4.4 Some long other text 5 some text 2 14.5 2.0 Some long other ...
1
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2answers
501 views

tail -f equivalent

I am seeing a delay of several seconds with the tail command. I found the cause for it has something to do with nfs services. I am using Arch linux and yet to find out how to disable all these ...
1
vote
2answers
595 views

How do you keep the password hidden when invoked during the su command?

This is the first time it has happened to me where I am using the su command and it actually displays the password on the terminal and doesn't stay hidden. Here is my code snippet: sshpass -p "...
1
vote
2answers
621 views

stdout , stderr and logging using the script command

I have remove.sh which contains: rm -v test.tmp And I have install.sh which contains: script remove.log -c './remove.sh' What can I do so that whether or not test.tmp exists, I don't see any rm ...
0
votes
2answers
5k views

Change motd value in UNIX Operating System

I need to change the value of MOTD using a script but I do not know how I should start. Am attaching sample MOTD if anyone can help.            
0
votes
2answers
103 views

Why is the suid bit having no effect on a shell or perl script? [duplicate]

As an experiment in playing with the suid bit, I tried writing a script to run apt-get update from a bash script, and then set the suid bit on it, so I could just run ~/update or something. apt-get ...
0
votes
1answer
911 views

Script with root permission [duplicate]

Possible Duplicate: Redirecting stdout to a file you don't have write permission on I am creating a script to change the brightness of my laptop. I discovered that I can do this using ...
0
votes
2answers
298 views

Autentification on SSH connection in OneLine [duplicate]

Possible Duplicate: Shell Script for logging into a ssh server I need to connect via SSH to a remote server, however I must do this with out interactive mode and with out use Public keys and ...
0
votes
2answers
2k views

Need help to make rows into column with awk or sed

Recently, I look for scripts to take this: This; Is; First; Line; and make it like: This Is First Line
-1
votes
1answer
107 views

just wanted to know what am i doing wrong in the end of this script that doesnt put my checkdate in to cal command

#Purpose: Validate a date #Usage: chkdate year month day # if [ $# -eq 0 ]; then echo Usage: chkdate year month day exit 0 fi year=$1; month=$2; day=$3; extra=$4 if [[ "$extra" != "" ]]...
38
votes
3answers
23k views

What does it mean to have a $“dollarsign-prefixed string” in a script?

I just saw this in an init script: echo $"Stopping Apache" What is that dollar-sign for? My research so far: I found this in the bash manual: extquote If set, $'string' and $"string"...
15
votes
4answers
39k views

printing colored text using echo

I know that for printing a colored text using echo, for example red color, the code is: echo -e "\e[1;31m This is red text \e[0m" and I know that in this example, 31 is code of red color and the ...
12
votes
7answers
3k views

Practical tasks to learn shell scripting

I'm looking for some common problems in unix system administration and ways that shell scripting can solve them. Completely for self-educational purposes. Also I'd like to know how would you go about ...
11
votes
1answer
2k views

Know which process does I/O without iotop

On Linux, I want to know which process uses my disk I/O bandwith. I know I can use iotop but I have a machine where, for various reasons, iotop cannot be installed. How can I manually get that ...
10
votes
1answer
6k views

Increase %e precision with /usr/bin/time shell command

When I run the time command in shell time ./myapp I get an output like the following: real 0m0.668s user 0m0.112s sys 0m0.028s However,when I run the command \time -f %e ./myapp I lose ...
14
votes
6answers
12k views

What are good online resources for learning shell scripting? [closed]

I am a beginner to shell scripting. I have not yet hardly coded a single program, but I am interested in learning it completely. Can anyone suggest some good online resources which will guide me?
16
votes
7answers
15k views

Faster way than ping for checking if computer online?

I'm writing a wake on lan script for a set of our lab computers. We have sqlite db with a list of the computer hostnames, IPs, and MACs and currently I ping each of them with '-c1' so it doesn't run ...
15
votes
1answer
5k 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 ...
9
votes
1answer
2k views

confirmed exit using trap

I am trying to trap the Ctrl+C signal asking a confirmation from the user. The trapping part works fine. But once the signal gets trapped, it does not return to the normal execution. Instead, it quits ...
5
votes
2answers
20k views

Execute shell script from php, as root user?

Need to execute the following line from PHP: $res = shell_exec('sudo sh /home/nicklas/cronjobs/make_account.sh username password'); The problem is nothing happens on execution. If i try to ...
4
votes
2answers
617 views

Shell script printing the most visited directories

Is there a way to write a bash script with the following functionalities? Be launched when I press some key or key combination. (not so important requirement) Identify the 7 most visited directories ...
14
votes
4answers
15k views

Invert boolean variable

I want to try simple script flag=false while !$flag do read x if [ "$x" -eq "true" ] then flag=true fi echo "${x} : ${flag}" done But when I run it, if I type true, I will see ...
11
votes
2answers
14k views

Excluding a directory when zipping files

I've got a bash script that does something like this: zip -0 ../backup/backup.zip \ -r ./* \ -x \*CVS\* \ -x *Thumbs.db* \ The directory it's backing up is a SVN archive (it used to be CVS back in ...
10
votes
3answers
888 views

How do you continue a sentence with a command inside

For example, I have been trying to say "There are 10 people online at the moment" in my script file. I can never seem to get the command working without the "people online at the moment" part on the ...
7
votes
4answers
6k views

Parallel execution of a program on multiple files

I have a small script that loops through all files of a folder and executes a (usually long lasting) command. Basically it's for file in ./folder/*; do ./bin/myProgram $file > ./done/$file ...
7
votes
5answers
27k views

Parsing a delimited text file in bash as command arguments

I have a text file split up like so: field1,field2,field3 xield1,xield2,xield3 dield1,dield2,dield3 gield1,gield2,gield3 Each of these columns will be a parameter to a program, and I would like ...
5
votes
4answers
336 views

Prefixing and appending blocks of text to a list of files

I'm trying to prefix and append blocks of text to a list of files. Here is where I am so far. The sticking point is the sed -i "1i \$prefix" "$file" && line. sed won't substitute the value of ...
3
votes
2answers
962 views

split a file, pass each piece as a param to a script, run each script in parallel

I have a words.txt with 10000 words (one to a line). I have 5,000 documents. I want to see which documents contain which of those words (with a regex pattern around the word). I have a script.sh that ...
3
votes
2answers
1k views

Convert a typescript file to a list of commands (history)

I wanted to record a linux session so I could use it as documentation for a "how to install" guide. I found something on the internet that suggested that the script command would be good for this, and ...