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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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?
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vote
1answer
88 views

Safe way to install .sh script in /usr/local/bin?

I want to include correctly the following script in Ubuntu 16.04. Code #!/bin/sh # http://tex.stackexchange.com/a/20886/13173 # $Id: pdf2eps,v 0.01 2005/10/28 00:55:46 Herbert Voss Exp $ # Convert ...
11
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
10k 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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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
710 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 ...
6
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 (that'...
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4answers
7k 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?
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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 ...
5
votes
1answer
143 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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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") ...
4
votes
2answers
53 views

Best way to delete select email messages from mbox file using script

I have an arbitrary email messages file in mbox format. I would like to periodically (end of the week), and automatically (via cron) purge messages from my "alerts" mbox file (new folder) just from ...
3
votes
5answers
540 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/ ...
3
votes
3answers
557 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. ...
2
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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
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
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1answer
78 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
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
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 ...
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
297 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 ...
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votes
2answers
1k 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 ...
1
vote
1answer
37 views

How can I edit my bash script to account for whitespace entries? [duplicate]

I made a script to automate ffmpeg conversion from mkv > m4v > open the m4v in Subler.app to import the metadata manually, at which point I'll move the file into my iTunes library. I use iTunes ...
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vote
2answers
105 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 /home/media/...
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vote
2answers
335 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
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3answers
21k 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, ...
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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 clearly....
7
votes
1answer
185 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 ...
6
votes
1answer
967 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 ...
6
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1answer
3k 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 ...
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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
485 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
3answers
279 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. ...
4
votes
5answers
205 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 ...
3
votes
1answer
83 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
2answers
414 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
623 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?
2
votes
2answers
203 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
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
1answer
56 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. ...
2
votes
3answers
276 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 (env,...
2
votes
5answers
2k views

Why is the first line comment of .sh file necessary? [duplicate]

I was told that the first line shebang (#!/bin/bash) is necessary in the shell script file, and the file won't run accurately without this line. But I tested some scripts. They work just fine without ...
2
votes
1answer
585 views

Script for courier maildir folders on CentOS LAMP environment

I'm looking for resources to help me build a script to do monthly maintenance of maildir folders for a typical CentOS LAMP VPS hosting environment. I would like to run a script that runs from a ...
2
votes
3answers
134 views

What is the language that appears on the first line of a script? [duplicate]

Bash scripts start with the following line #!/bin/bash # Rest of script below ... In bash the # character is the start of a comment, but #!/bin/bash is definitely not a comment, therefore it isn't ...
2
votes
2answers
5k views

/usr/bin/env: zsh -: No such file or directory

I get the error /usr/bin/env: zsh -: No such file or directory ...when I run an executable zsh script that starts with the following shebang line: #!/usr/bin/env zsh - Also, FWIW, replacing - ...
2
votes
1answer
52 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
2answers
106 views

Scripting to domain allocation to server

I have two text files: file #1: domain.txt cocacola.com airtel.com pepsi.com file #2: servers.txt 192.0.53.42 , 4 # 4 domains already allocated on server 192.0.53.42 192.53.1.2 , 1 # 1 ...
2
votes
3answers
4k views

Comparing text files using Bash and AWK

I have two text files, and I want to compare their corresponding values according to their rows and columns. By comparing, I mean to check if the values are equal and echo if the values are the same ...