Questions tagged [posix]
POSIX is an acronym for Portable Operating System Interface, a set of standards defining programming APIs and utility behavior for Unix-like operating systems.
67
questions
12
votes
3answers
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Correctly applying the “rule of five” to a RAII socket wrapper
I was trying to create a simple RAII wrapper with rule of 5 for a TCP POSIX socket. My aim was to try learn how to apply rule of five in different situations, but this one was somehow tricky.
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-4
votes
1answer
54 views
Defining constants in the original standard of C [closed]
I'm learning C using Mike McGraths 3rd edition. I know the book is old but I want to have a better appreciation for the changes made to C through its timeline. The compiler error is error: ‘SYSTEM’ ...
5
votes
1answer
44 views
POSIX+ implementations of echo(1)
Ever wanted a strictly conformant echo(1) implementation on your system? Wait no more: I've built it!
What is it?
My first large-ish body of C code in a while.
...
6
votes
0answers
72 views
Console arkanoid in C
On an Internet forum a person came with their homework, to write Arkanoid in a console - it seemed they wanted someone to do their homework for them so I did not respond. However, I found the task ...
8
votes
1answer
149 views
Custom malloc implementation
I have a malloc() implementation that relies purely on mmap. I'm fairly sure that it doesn't overwrite any of the internal ...
1
vote
1answer
72 views
Bash Code to backup the history file in Linux [closed]
How is the logic, efficiency and can it be improved?
This is a snippet from my .bashrc file, I just wrote it.
The code is supposed to do this:
Backup my ...
3
votes
2answers
65 views
POSIX shell function for asking questions
I've written a tiny function for asking questions intended for my POSIX shell scripts, where I often need user input.
The function takes 2+ arguments, where:
Is a string containing the question.
, 3....
3
votes
1answer
33 views
batch add users to nextcloud on docker with csv
I have a working script that will batch add users to an instance of nextcloud running on top of docker. This version is the result of changes made after asking this question.
I guess I'm looking for ...
2
votes
1answer
84 views
Editing system files in Linux (as root) with GUI and CLI text editors
My intention is to POSIX-ly write one generalized function for running various text editors I use for different purposes through sudoedit, i.e. editing files as ...
3
votes
1answer
24 views
Is device mounted? Both UUID and device names accepted
I am trying to write is_device_mounted script, which in turn will serve a greater purpose in my home Linux system.
It does not even have an error reporting ...
2
votes
1answer
28 views
C Recursive Opendir Wrapper to Sort Directories First (ascending/descending)
A recent post on StackOverflow about a recursive directory listing which produced an unsorted mixed file/directory list, sparked the stray thought of "What would it take to write a wrapper for the ...
2
votes
2answers
47 views
Lock file and interrupt signals in POSIX shell script running indefinitely
This script is running indefinitely as the Linux background process.
I have put an enormous effort to make this POSIX shell script containing an infinite loop shut down tidily along with the ...
2
votes
2answers
42 views
POSIX-ly finding a specific Java process
In this code I find a list all of the running java processes and give the below function a name to look for, it will do its best. But since I find my approach a ...
3
votes
1answer
57 views
Easy to use code preparation script for CodeReview questions
We all face questions that forget to include their code. Sometimes all of it, sometimes only parts, that make the rest of the question unfortunately incomplete and therefore off-topic.
What if it was ...
1
vote
1answer
49 views
Detecting the total amount of RAM installed on a hardware from a Linux system using a POSIX shell script
Today, I gave myself a small task of detecting the total amount of RAM installed on a hardware from a Linux system using a POSIX shell script. I ended up using ...
0
votes
1answer
27 views
Shell POSIX OpenSSL file decryption script follow-up #3 (final)
From original very simplistic code: Shell POSIX OpenSSL file decryption script
I learned a lot both from the first follow-up review, and the second one as well, many thanks!
I just need one final ...
0
votes
1answer
46 views
Shell POSIX OpenSSL file decryption script follow-up #2
This question is the second follow-up of: Shell POSIX OpenSSL file decryption script
The first follow-up was: Shell POSIX OpenSSL file decryption script follow-up #1
Both of which have proven very ...
26
votes
6answers
8k views
Create a C style char** from a C++ vector<string>
I am dealing with some older C style APIs, like Posix execve that take a char**. In the rest of my code, I prefer to use a ...
3
votes
2answers
107 views
Generic error handler function for POSIX shell scripts
Intention
I came with the idea of generic, portable, highly reliable, and further customizable function for Shell scripts, written in POSIX, for error handling.
Purpose
The function shall find out, ...
1
vote
2answers
168 views
Long-term archiving + encrypting shell script
Yesterday, I very quickly, in an hour, wrote the very first version of my long-term archiving + encrypting shell script.
I am aware it may have too many flaws, but none of them really prevent it from ...
5
votes
1answer
146 views
Lightshot Print Screen key linux handler - Follow-up #1
This question is a direct follow-up #1 of my previous question:
Lightshot Print Screen key linux handler
There were too many errors which I didn't see at the moment and I tried hard to fix them up ...
7
votes
4answers
627 views
Calculating linux based octal file permission
I'm applying for a mid level devloper position.
In order to progress to 2nd interview, you need to pass a technical test.
One of the questions was to write a function to work out linux based octal ...
3
votes
1answer
103 views
Lightshot Print Screen key linux handler
I haven't found any Lightshot Print Screen key linux handler publicly available.
So, I decided to write one today. It is a standard POSIX shell script.
I believe there is always space to get better, ...
5
votes
2answers
87 views
Goodgame Empire coin collector with random offsets in (almost-POSIX) Bash
Today, my goal was again to improve my POSIX shell scripting abilities.
In one MMO game called Goodgame Empire, there is possible to code yourself a coin (tax) collector. But that's of less ...
0
votes
1answer
200 views
POSIX shell script for generating pseudo-random numbers
My today's goal was to further practice POSIX shell scripting.
So, I decided to write the following POSIX shell script for generating pseudo-random numbers.
Any and all reviews would be appreciated.
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1
vote
1answer
91 views
Shell POSIX OpenSSL file decryption script follow-up #1
This question is the first follow-up of: Shell POSIX OpenSSL file decryption script
Please read it before you continue reading this. Thank you.
I only have one new problem solved and I would like ...
2
votes
0answers
60 views
Shell script to manage passwords
To get my feet wet with shell scripting I wrote this "minimal command line
password manager" (aka pwm) taking inspiration from the well known ...
5
votes
1answer
119 views
Interactive Linux upgrade script
One year ago, I asked for a review of Simple Linux upgrade script in Bash.
Conditions are slightly changed, and/or more accurate:
Code readability for the code user, making it simple to adjust the ...
2
votes
2answers
45 views
How long a PID has been running (taking multiple inputs)
Tonight I tried to write a POSIX shell script which would allow me to check how long a process is running (via it's ID) and be able to handle multiple inputs:
...
5
votes
1answer
568 views
Shell POSIX OpenSSL file decryption script
Tonight, I tried to write a Bash OpenSSL file decryption script. Encryption script will follow in highly similar manner, so I think it's not necessary now.
Let's suppose we have an encrypted large ...
2
votes
1answer
49 views
Implementing POSIX file mode library
I implemented a virtual file system library with POSIX file mode representation.
Any suggestions regarding optimization are welcome.
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3
votes
1answer
104 views
Shell script for reading /etc/passwd into SQLite
I want to read 4 columns, namely UID, GID, username and home directory of specific users from /etc/passwd into an SQLite database. I found this to create many ...
2
votes
1answer
2k views
C++ wrappers for execv(3)
Calling execv(3) (and similar functions) in C++ can be
problematic. execv expects an array of const pointers to
non-const ...
3
votes
0answers
768 views
SIGCONT Handler for terminal application
I'm writing a C++ application for POSIX environment with terminal-based User Interface. I'd like to make my application's UI be consistent between Ctrl-Z and ...
3
votes
1answer
75 views
Showing all programs' man pages
I'm trying to discover useful command line tools in Arch Linux, and it seems one good way of going about that is to look through all of the man pages related to ...
4
votes
0answers
30 views
Launch and place application depending on screen resolution
I got fed up off opening a set of applications when I wanted to code. So I decided to read up on AppleScript and came up with the following task for myself.
Open a application of choice on a given ...
5
votes
0answers
125 views
Semaphore implementation by file locking in a bash script
This implementation is inspired by the POSIX functions sem_wait() and sem_post(). It tries to get rid of busy loops in the code ...
-2
votes
1answer
2k views
Printing infinite loop using pthread [closed]
I'm trying to implement a c program using pthreads which prints "1 2 3 4 5" in an infinite loop. I have used conditional variables and mutex to synchronize the pthreads. I'm able to print "1 2 3 4 5" ...
0
votes
1answer
46 views
Split a file into individually allocated lines
This is part of a larger project that is to run on POSIX systems. My concerns with it are the lack of comments, best practices with the filesystem, and naming things. Of course all feedback is great.
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3
votes
1answer
220 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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-4
votes
1answer
66 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 ...
0
votes
1answer
97 views
C function for copying array into matrix
I want a matrix that can grow dynamically and build up a structure in RAM as input arrives from standard input och terminal (shell). First I tried with a matrix like ...
0
votes
1answer
107 views
Shell command line program
I have refactored a for loop into a function. I'm still a beginner at using C utility functions such as strtok, ...
2
votes
1answer
106 views
Makefile and main header file for a shell
My main.c includes this header file. Please let me know how I can improve it. I did my best but I don't know much about code conventions in C (I come from Java and ...
5
votes
1answer
108 views
run command pipeline in C
This code parses and tokenizes my shell language command interpreter. I will try and make it 2 functions, one that is the tokenizer and the other that is the rest of the function. Can you find ...
-1
votes
1answer
107 views
C stack for Linux and BSD
My stack uses char data and is not tested. I use it to save command in a unix pipeline for my own POSIX shell. Maybe you can find a bug or a possible improvement.
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2
votes
1answer
83 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 ...
0
votes
1answer
40 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?
...
2
votes
1answer
41 views
C function to find the less program
I've written a C function to find the program less that the operating system should provide. If lessis not provided, some other ...
11
votes
1answer
188 views
Recreation of cat in C
I have a school project to create a program that works the same as the Linux cat. The code works, but I just need find out where I can Improve it or handle errors. ...
