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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327 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 ...
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votes
5answers
5k views

How do you colorize only some keywords for a bash script?

I am running some unit test code. The unit test code outputs regular text. There is a lot of the text so I want to highlight for the user important keywords. In this case the keywords are "PASS" and ...
3
votes
2answers
859 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 ...
2
votes
1answer
1k views

Shell script filtering through jpg files attributes

I'm trying to find a way to filter through thousands of jpg files, and keep only the files with a certain attribute (such as the camera brand with which the picture was captured). How can I do so?
12
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 ...
10
votes
1answer
2k views

Copy image from clipboard to file

Is it possible to take an image from the clipboard and output it to a file (using X)? I can do this with text easily: $ xclip -selection c -o > file.text But when I try the above with an image ...
8
votes
7answers
9k views

Extracting nested zip files

I have numerous zip archives, each of which contains a number of zip archives. What is the best way to recursively extract all files contained within this zip archive and its child zip archives, that ...
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votes
2answers
2k views

sync files recursively between two folders where files are less than 24 hours old

I want to find all the files under a directory which are within 24 hours then rsync those files with another server. There are some old files that I do not want to transfer, however if those old ...
6
votes
6answers
685 views

bash: how do you return file extensions?

I want to write a script to return just the extension of the input file name. For example, textfile.txt should return txt. I'm new to Linux and bash, and I'm trying to learn how to write basic ...
5
votes
3answers
4k views

How to iterate through a list of files with spaces that is sorted (case insensitive)?

I am doing this in OSX which uses bash but obviously, not all bash conventions are used so hopefully your suggestion is available to me :) I have the following files fun bar1.txt Foo bar2.tXT ...
5
votes
1answer
133 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).
5
votes
1answer
4k views

Changing password in multiple boxes using script

I'm working in a environment which has around 400 AIX boxes. I don't have root access and I'm a normal user. The environment has no LDAP kind of centralized mechanism for authentication so the ...
4
votes
4answers
6k views

How to use wc and piping to find how many files and directories are in a certain directory?

How can I use word counter and piping to count how many files or directories are in /usr/bin directory?
4
votes
5answers
3k views

Replacing text from a list of replacements. Added complication: backslashes

I have a file A that contains pairs of strings, one per line: \old1 \new1 \old2 \new2 ..... I would like to iterate over file A, and for each line perform the replacement (e.g. "\old1 -> \new1") ...
3
votes
3answers
524 views

Processing input line by line (with empty lines) from shell

In a shell script, I need to parse the output of a command line-by-line. The output may include empty lines, and these are relevant. I am using ash, not bash, so cannot resort to process substitution. ...
3
votes
5answers
521 views

How can I force a script to use more resources?

I'm running a very time-consuming script which takes many hours to end. Watching top I see that it's only taking 5% of the CPU at best, usually around 3%. Is there any way to force the script to use ...
3
votes
3answers
240 views

Permissions for a submission script

I'm a TA for an introductory Python programming class (all work is done from the terminal), and I'm writing a project submission script. Ideally I want a directory setup like this: submissions/ ...
2
votes
1answer
77 views

How to write this replacement with condition

I want to replace now within my working directories the word -> with $\to$ if the word is not within verbatim environment. Pseudocode Replace all entriens of -> with $\to$ everywhere else but not ...
2
votes
1answer
269 views

Get the full window dimensions (including decorations) in Unity

I have used the answer to How do I find the window dimensions and position accurately including decorations? in my bash scripts, and had good success with my Silentcast application on Xfce, but now ...
2
votes
3answers
4k views

Extracting characters after a particular text

I am extracting a page from website using cURL command. curl "www.google.com" -s | w3m -dump -T text/html > foo.txt The w3m command outputs the HTML page in a much more simpler format so that ...
2
votes
1answer
2k views

How can you run a script triggered by a joystick input?

I'm using a Raspberry Pi running Raspbian to power my arcade cabinet. I want to shut the Pi down using the sudo poweroff command without using the keyboard. I'm thinking the best way would be to ...
2
votes
2answers
3k views

Concatenate multiple files under subdirectories

My directory structure is given below x:\Project_2012-158A\Sample_4041 SampleSheet.csv 4041_CGTACG_L002_R1_001.fastq 4041_CGTACG_L002_R2_001.fastq 4041_CGTACG_L006_R2_001.fastq ...
2
votes
2answers
1k views

How can I queue processes?

I have a surveillance camera and a program records videos when motion is detected. Basically, this program saves the video in a very heavy format. My solution was to call a script that converts the ...
2
votes
4answers
2k views

Anacron job complains “Gtk-WARNING **: cannot open display”

I'm trying to make a simple weekly Anacron job that backs up my computer if I click yes on the dialog. The script I wrote works fine if run manually, but when Anacron runs it, nothing happens and I ...
1
vote
2answers
104 views

identify harddrive before mounting

I've recently made 2 script that take care of mounting and dismounting a harddrive in linux. The thing that I could not figure out is the following. I am currently mounting /dev/sdc1 to ...
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vote
2answers
316 views

How to notice log file changes with Linux standard tools? [duplicate]

I need something that does not need to be installed. It's on an embedded system with very little space on the HD. I can't instal anything. I need to do it with something that is already included. I ...
11
votes
3answers
19k views

Execute a command on user logon

In Linux desktop system, I want to execute a command when the user logs in. After reading some other posts, I tried to insert the command in ~/.bashrc but unsuccessfully. Moreover, the system uses a ...
9
votes
2answers
2k views

How to non-invasively test for write access to a file?

In a shell script, how do I easily and non-invasively test for write access to a file without actually attempting to modify the file? I could parse the output of stat, but that seems really complex, ...
7
votes
1answer
182 views

Is there any guarantee that /usr/bin/env will exist?

Often I will see scripts begin with a shebang line that uses #!/usr/bin/env interpreter_name for whatever interpreter, with the rationale that different systems might have the interpreter that they ...
7
votes
1answer
2k views

Problems running python script from motion

I'm trying to set up the raspberry pi with my webcam as a motion detecting cctv that uploads the videos to google drive using Jeremy Blythe's script I have motion working correctly and the python ...
7
votes
4answers
8k views

Can IFS (Internal Field Separator) function as a single seperator for multiple consecutive delim chars?

Parsing an array using IFS with non-whites space values creates empty elements. Even using tr -s to shrink multiple delims to a single delim isn't enough. An example may explain the issue more ...
6
votes
1answer
2k views

Converting .docx files to plain text and preserving line breaks to maintain line number references to source document: howto & implications?

I'm exporting MS Word content to plain text for use with text&file utilities. I have a constraint where the line numbering feature has been enabled in the MS software, and any reference to line ...
6
votes
1answer
901 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 ...
5
votes
3answers
1k views

securely automating a script which requires a key to do its task

I have a script that downloads bank transactions to store in a database. To get these transactions requires a password for each account. The database is encrypted and requires a key to access it. All ...
5
votes
2answers
467 views

Exiting a pipeline if a former command fails

I'm trying to check the number of running and queued PBS jobs by parsing the output of qstat -tn1 from a bash script. So far, this has worked: count () { qstat -tn1 | awk ' BEGIN { R = 0; ...
4
votes
5answers
201 views

How shrink test -eq expression with more than one var value in /bin/sh

#!/bin/sh if [ $num -eq 9 -o $num -eq 75 -o $num -eq 200 ]; then echo "do this" elif [ $num -eq 40 -o $num -eq 53 -o $num -eq 63]; then echo "do something for this" else echo "for other do ...
4
votes
3answers
275 views

shell script problem with using the operators

I am comparing two strings using the levenshtein distance algorithm. I got the PHP implementation of the algorithm from here. I am calling this php implementation from my shell script as below. ...
3
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
389 views

Finding missing value in text file

I have a text file with following data. Name Feature Marry Lecturer Marry Student Marry Leader Bob Lecturer Bob Student ...
3
votes
4answers
571 views

Is there a difference between ./script and bash script? [duplicate]

Given a shell script file that begins as #!/bin/bash # (bash script here), and has been chmod +xed, is there any difference in running ./script and bash script from the command-line?
3
votes
1answer
82 views

Script not getting executed as per expectation

I have two Perl scripts at a predefined location in Unix. This predefined location is set in path variable ($PATH). Now when i try to run first script (from any location) the script runs successfully ...
3
votes
7answers
3k 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 ...
2
votes
2answers
43 views

Check Input Prior to Executing a “for loop”

is there any way to check or test the input from a 'read' against a for 'loop'? I don't want the case statement to execute there any of the input is incorrect. As of right now it will loop through, ...
2
votes
3answers
900 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 ...
2
votes
1answer
49 views

Copy files that partially matches another files in another location

I have a list of jpeg files in a directory like this (below is just a sample, like the structure is the same but this there are many fo0# sub-folders, not only fo01 and fo01, where each of these ...
2
votes
1answer
352 views

use mutt to send email through specific port on CentOS 7

What specific syntax do I use to get mutt to send an email through port 587 on a CentOS 7 server? For example, the sender is me@mydomain.com, the recipient is someone.else@someotherdomain.com, the ...
2
votes
2answers
186 views

Is it better to use a shebang line to execute a script?

I was looking up shebang and wondering why I would use it. I could execute a bash script using: bash foo.sh or ./foo.sh (with a shebang line in foo.sh) What are the pros and cons of each and ...
2
votes
3answers
260 views

How can I print only variables defined inside my shell script?

Lets supose some bash shell script like: #!/bin/bash a=3 b=7 set -o posix set In this case, the execution of the set variable or some other of the commands to print environment variables ...
2
votes
1answer
55 views

Neutralisation of data from Windows to Unix

I just noticed that other platforms files (Windows) had to cause me many bugs, like here, in my regexes. Mostly, the line ending ^M. There seems to be many ways to do dos2unix, like here described. ...