The term 'shell' refers to a general class of text-based command interpreters most often associated with the Unix & Linux operating systems.

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Install ruby using rbenv in bash script

I want to write an automated bash script for installing ruby and rails using rbenv. But I am getting issue of session reload in terminal. My bash script:- ...
3
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1answer
79 views

POSIX arithmetic expansion

I understand that a shell should be able to perform arithmetic expansion. My shell can do it: $ echo $((1+2*3+4*5)) 27 My solution uses the lemon parser where I ...
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1answer
60 views

Running shell commands in a pipeline

I'm writing a shell in C for Linux and BSD. My code was unreadable before but I did a rewrite and now it is much more readable. The purpose of the code is to create a command pipeline and execute it. ...
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1answer
42 views

Creating a struct

Mat told me to create a struct create a struct for the individual commands and arguments. It should have something like the "executable" name, number of args and arg list. Create a few ...
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2answers
49 views

Shell command-line interpreter with pipeline parsing

Like many others I've been writing a shell command-line interpreter that can do a pretty decent pipeline parsing, first it splits the command at pipeline char (|), then it splits the substring at ...
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1answer
26 views

Displaying a table of shell aliases

I'm just getting into bash and sh scripting. I mostly just stub out little convenience or exercise scripts for myself, but I recognize I may be flaunting best practices at times. My question is ...
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1answer
49 views

C main function for POSIX shell

I got a pretty large main function that I want to break up in smaller helper functions. Can you help me suggest what to break out into helper functions? The ...
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1answer
27 views

Handle builtin commands

I've written a small C function to handle the builtin commands of a custom shell that I'm writing in C. Is it better to use a switch instead? ...
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1answer
71 views

Tokenizing a shell command

I want to handle input like the following ls -al | awk '{print $1}' Now to parse it I couldn't tokenize at whitespace because of the quotations and I had to make ...
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1answer
34 views

Simple shell script to backup to Amazon over iSCSI

The script works but I know that it can be improved. Please note that my scripting skills are very basic :) (as it can be seen in my Frankenstein script – I took bits and pieces of the code from ...
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1answer
44 views

Display the last N lines of a text file with line numbers in reverse order

Do you think the way I'm doing it is fine? Is this the most typical way to do it? Share your thoughts please. ...
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1answer
24 views

POSIX shell script using a string to store command arguments

Background I’ve started putting all my configuration files (which include many shell files) under version control. In the Git repository, I’ve configured a pre-commit hook that runs the ...
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0answers
50 views

Resolving the path to a Bash script

I wrote a function to resolve the full path to the current Bash script, and I'm wondering if it's SOLID: ...
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2answers
75 views

MS-DOS style OS

This is a very basic text-based operating system I've been working on. I started working with python a few weeks ago and this project only a few days ago, so there are probably better ways I can do ...
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1answer
51 views

Ruby backup/restore for provisioning

This is my second Ruby coding attempt. Also - this is my first OOP usage in Ruby. I'm using if __FILE__ == $0 form here - same as it is in Python because it's ...
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1answer
19 views

Shell agnostic startup flow - env, profile, rc, login

The goal of these files is to have some common behavior between Bash and Zsh when starting them. As is known, when Bash starts as a login shell it will source the first found of the following in your ...
3
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2answers
46 views

Nagios plugin webdav check 2

Original post: nagios plugin webdav check According to the good advice I have received I've made some modifications to the code: ...
4
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1answer
122 views

FFmpeg command line for showing two videos side by side

Here is command line for playing two videos side by side in sync in FFmpeg (ffplay). It can be useful for comaring videos, for example. ...
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0answers
134 views

Extracting single files from a tarball (spreadsheets)

I've created a program that will pull spreadsheets out of a large tarball. First it specifies the file name through the "folio" number which is given as an argument when the program is called. From ...
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2answers
86 views

Basic shell implementation

Here is a small project to implement a basic shell. It is a personal ongoing project to keep system call usage fresh. It currently does background processes and some basic signal handling. I am ...
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1answer
79 views

Constructing a simple shell from scratch

I'm actually doing my whole shell in C from scratch from a Linux computer. The thing is that I think we all do our best from creating the simplest things that can be explained easily. And I'm not sure ...
5
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1answer
47 views

Function to get specified key from /proc/cpuinfo

On Linux, the file /proc/cpuinfo returns a set of key-value pairs, where the key and value are separated by a colon and each pair has its own line. It's a bit more ...
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1answer
31 views

Print values of an array while stripping out some parts of the string

Is there a more efficient way to run this? I am especially interested in a way which perhaps does not require a for loop... ...
7
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1answer
104 views

Detecting keyboard input

I want to use JavaFX as a solution to Java's issues with buffered input making things like 'press any key to continue' not easy. I plan to use an event listener to detect keyboard input. But before I ...
11
votes
2answers
253 views

Editing Javascript and rendering HTML in one window v2

I wanted to revisit this site to post some recent work I put into this small project. I was able to add a console as suggested; but I thought I would ask here how my coding stying is before I work on ...
10
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3answers
428 views

Shell Script (Bash) to sum multiples of different arguments below a number

I'm interested in learning how to create shell scripts with bash so here's one of my first exercises, taken from here. It is an extension of the problems Elementary - 4 and 5. The goal of the program ...
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1answer
44 views

Expanding tilde inside assignments and strings in bash

Inspired by the work Charles Duffy did in this answer and the work of Jonathan Leffler in this one and because I couldn't leave well-enough alone. I went and wrote expandTilde.sh: ...
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1answer
43 views

Git post-receive hook writen as a POSIX shell script (utilising a named pipe)

This is my first piece of code to post here. I wrote this script as a post-receive hook for a Git repository but I’m not so concerned with the Git parts (I’d like to have the part marked with ...
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1answer
56 views

Merging files in Bash

I had this homework assignment: Create on the desktop a folder with your name. Copy from your account XYZ@xyz.com two files, ...
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2answers
110 views

Bash script to capture error message and change exit status

I'm working with the Perforce command line client. I ...
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1answer
50 views

Print a “shebang” line, or prepend it to a file

This is a sort-of-useless "utility" I wrote to learn my way around shell programming better. My concerns are: Is the code readable? Could it be more efficient, or just simpler? The logic ends up ...
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2answers
35 views

Split redirecting to multiple files in bash

A function mycommand which runs command and: Gives me three log-files which are: *.stdout.log: everything from ...
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1answer
77 views

POSIX shell compatible and POSIX conforming dirname implementation

The discussion in the comments of this answer made me wonder how hard it would be to write a built-in only version of dirname. This is what I ended up with but I'm ...
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3answers
89 views

Shell script to detect router slider status

I have an openwrt router (TP-Link MR3040) and on boot I have it check the slider (AP, WISP, 3G/4G mode). The goal was to have it execute the current "slider status" vs the old one, or do nothing if ...
5
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1answer
27 views

Shell Script Audio Logger

I created my first shell script. It's an audio logger that runs on the hour for an hour and restarts. Although if it is started within the hour it will only run until the end of the hour. I've added ...
4
votes
1answer
52 views

Optimising script that does simple renaming of files

I have recently written some code in Bash where I'm starting to program some things and I think I'm overcomplicating the script I wrote. I'd like to make it simpler so that in future I would avoid ...
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2answers
158 views

A basic C Shell for Linux

I have written a basic C Shell. It features the builtins cd, programmer, ver and ...
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2answers
129 views

Backup Linux system to web

First I create a .tar of the root directory with all the file permissions saved and excluding all irrelevant directories (are these the right folders to be ...
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1answer
35 views

Removing ASCII “frame” around text

I sometimes save nice fortune outputs to my Evernote. The data looks like this: ...
3
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1answer
51 views

Shell binary search with sorted input

I have coded binary search in shell, just for practice. Input Input data is already sorted set of numbers streamed to the script. $1 is the sought number. ...
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1answer
54 views

Remove line numbers from shell history

I want to parse Linux history output and the commands parts only (without numbers): ...
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2answers
324 views

Address book app to learn bash

I'm fairly proficient in C and Python, but want to learn some skills for administrating my new Linux machine. I wrote this simple address book app to teach myself shell scripting. This is the first ...
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3answers
182 views

Validating a credit card number using Luhn's algorithm

I implemented Luhn's algorithm explained on Wikipedia to validate a credit card number, in Bash. Does this code follow good practices? ...
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1answer
43 views

Unix shell script with master and source files

I have a script which is having too many modules. The script is working perfectly, but the only issue is it is taking too much time and I need to reduce the complexity of the script. I have a source ...
4
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3answers
69 views

Checking dates against a .properties file

I am writing a script that will check the set values against a .properties file and I am just wondering if there is any nicer way to write what I have here. ...
2
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0answers
69 views

Parallelized image transformations using GraphicsMagick

This is part of a script that I use for porting a TWRP Theme from one resolution to another. Respectively portrait to portrait and landscape to landscape. In this function entirely, it focuses on the ...
4
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1answer
340 views

Shell script that copies configuration and dotfiles to repository

A while ago I had the idea to store all the important configuration and dotfiles from my system in a Git repository. That saved me a few months ago: My harddrive died, but I could get back to work ...
8
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2answers
156 views

Recovery Shell (rsh)

I wrote a shell to test my understanding of processes etc. It is not supposed to comply with POSIX or anything, just to allow people to run simple commands with simple arguments. ...
4
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3answers
180 views

Bash script that checks if font is installed and installs it if necessary

This checks if a font is installed by using fc-list and grep. If the particular font is not installed, it offers to install it ...
5
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2answers
79 views

SSH chatting tool

I have taught myself some bash and already knew some AppleScript, so I have come up with this SSH chatting tool for OS X users. It allows you to chat from a terminal to another OS X computer. One ...