# chmod A command-line utility that changes access permissions of named files. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## Kubernetes v1.37: Hardening Container Storage with Bind Mount Options and EmptyDir Permissions DevFeed: [Kubernetes v1.37: Hardening Container Storage with Bind Mount Options and EmptyDir Permissions]() Original publisher: [Read original article]() Author: Nispriha Jagan; Neeraj Krishna Gopalakrishna Published: 2026-09-16T18:30:00Z Content type: article Language: en Sources: [Kubernetes Blog]() Topics: [Kubernetes](), [Security](), [mount](), [Filesystems](), [chmod](), [Unix]() Tags: [chmod](), [container](), [containers](), [filesystem](), [hardening](), [kubernetes](), [linux](), [mount](), [permissions](), [storage](), [volume](), [volumes]() ### AI overview Kubernetes v1.37 adds bind mount options and emptyDir permission modes to strengthen storage security. The article explains how noexec, nosuid, nodev, Unix permissions, and the sticky bit can help enforce security policies on writable volumes. ### Source excerpt Kubernetes v1.37 brings important storage security features: emptyDir permission modes and bind mount options. They help application programmers and security professionals implement rigorous security policies, for example, prohibiting deletion of files across containers or execution of arbitrary binaries from writable volumes, directly in Kubernetes without any complicated circumvention. Linux storage and permission fundamentals Before diving into the new Kubernetes features, let us briefly review the low-level Linux security mechanisms that make them possible. Bind mount flags When Linux mounts or remounts a directory, Virtual File System (VFS) flags control what actions are permitted on that filesystem: noexec: Do not permit direct execution of any binaries on the mounted filesystem. nosuid: Do not allow set-user-identifier or set-group-identifier bits to take effect. nodev: Do not interpret character or block special devices on the file system. Directory permissions and the sticky bit Standard Unix permissions regulate access across three scopes: Owner, Group, and Others (e.g., 0755 or 0777). Beyond standard read, write, and execute bits, Linux supports the sticky bit (as in mode 01777). When applied to a directory, the sticky bit ensures that a file inside that directory can only be deleted or renamed by the file's owner or root. This is essential for shared writable directories like /tmp. Motivation for the improvements Why does Kubernetes need bind mount options and emptyDir permissions? The primary goal of these features is to increase the security of Kubernetes workloads by allowing security-related bind mount options on volume mounts. By default, volumes are bind-mounted into containers by the container runtime and kubelet without noexec, nosuid, or nodev flags. This default can undermine security. For example, with noexec missing, a compromised process can use any writable volume (emptyDir, PersistentVolume, etc.) to download, chmod +x, and execute arbitra ## GNU Coreutils 9.12 Released With Performance Optimizations, New uname Option DevFeed: [GNU Coreutils 9.12 Released With Performance Optimizations, New uname Option]() Original publisher: [Read original article]() Author: Michael Larabel Published: 2026-09-14T17:45:05Z Content type: news Language: en Sources: [Phoronix]() Topics: [systems](), [Filesystems](), [Optimization](), [bug](), [chmod](), [ls]() Tags: [bug](), [chmod](), [core](), [desktop-linux](), [linux-benchmarking](), [linux-hardware-benchmarks](), [linux-hardware-reviews](), [linux-how-to](), [linux-performance](), [linux-server-benchmarks](), [ls](), [open-source-graphics](), [optimization](), [performance](), [phoronix](), [phoronix-test-suite](), [release](), [systems](), [ubuntu-benchmarks](), [ubuntu-hardware]() ### AI overview GNU Coreutils 9.12 fixes recursive traversal failures when files are removed concurrently, adds FailFS and NULLFS support to stat and tail, and introduces new uname labeling options. It also improves performance in cut, uniq, and sort, adds a copy fallback for cp, install, and mv, and includes additional bug fixes and warnings. ### Source excerpt GNU Coreutils 9.12 released today with a mix of fixes, some new options, and various performance improvements to these widely-used set of core system utilities... ## Sandbox SDK adds file permission control DevFeed: [Sandbox SDK adds file permission control]() Original publisher: [Read original article]() Author: Luke Phillips-Sheard Published: 2026-03-20T00:00:00Z Content type: release Language: en Sources: [Vercel News]() Topics: [SDKs](), [Vercel](), [API](), [chmod](), [Script](), [Authorization]() Tags: [api](), [chmod](), [documentation](), [sandbox](), [sdk](), [vercel]() ### AI overview Vercel Sandbox SDK 1.9.0 adds direct file-permission control when writing files through the writeFiles API. A mode property lets developers set permissions in the same operation, avoiding an extra chmod execution round trip. ### Source excerpt Vercel Sandbox SDK 1.9.0 now supports setting file permissions directly when writing files. By passing a mode property to the writeFiles API, you can define permissions in a single operation. This eliminates the need for an additional chmod execution round-trip when creating executable scripts or managing access rights inside the sandbox. See the documentation to learn more. Read more ## Permisos en Linux: chmod, chown y ACLs explicados DevFeed: [Permisos en Linux: chmod, chown y ACLs explicados]() Original publisher: [Read original article]() Author: Antonio Pérez Published: 2026-01-18T00:00:00Z Content type: tutorial Language: es Sources: [tengoping.com]() Topics: [Linux](), [chmod](), [Kernel]() Tags: [chmod](), [kernel](), [linux](), [octal](), [permission](), [ssh]() ### AI overview A Spanish-language tutorial explains Linux file permissions, including owner/group/others resolution, directory access semantics, octal and symbolic chmod notation, recursive chmod pitfalls, SSH private-key permissions, ACL masks, umask, and extended attributes. ### Source excerpt Permisos en Linux en profundidad: cómo se resuelven owner/group/others, umask, la trampa de chmod -R, ACLs con mask y chattr. ## Linux shell script to reduce PDF file size DevFeed: [Linux shell script to reduce PDF file size]() Original publisher: [Read original article]() Author: Vivek Gite Published: 2024-07-30T22:56:26Z Content type: tutorial Language: en Sources: [nixCraft: Linux Tips, Hacks, Tutorials, And Ideas In Blog Format (RSS/FEED)]() Topics: [Linux](), [Shell](), [Script](), [pdf](), [Bash](), [Command-line interface](), [chmod](), [Unix]() Tags: [bash](), [bash-shell](), [chmod](), [easy](), [linux](), [pdf](), [script](), [shell](), [shell-script](), [terminal](), [unix]() ### AI overview A tutorial presents a shell script that uses Ghostscript to reduce the size of scanned PDF files on Linux and other Unix-like systems. It covers installing the script, setting executable permissions, running it, and comparing the original and compressed file sizes. ### Source excerpt Here is a handy and useful Linux and Unix shell script that reduce PDF file size using Ghostscript. No need to upload your PDF file to the shady third-party website. Just do it from the terminal. I tested it with both CentOS and Ubuntu/Debian Linux. It should work with macOS, FreeBSD and other Unix-like systems as long as you have the Ghostscript installed. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux shell script to reduce PDF file size appeared first on nixCraft. ## How to copy permissions from one file to another on Linux DevFeed: [How to copy permissions from one file to another on Linux]() Original publisher: [Read original article]() Author: Vivek Gite Published: 2024-05-08T22:06:06Z Content type: tutorial Language: en Sources: [nixCraft: Linux Tips, Hacks, Tutorials, And Ideas In Blog Format (RSS/FEED)]() Topics: [Linux](), [chmod](), [Access Control](), [Command-line interface]() Tags: [access-control](), [bash-shell](), [centos](), [chmod](), [chmod-command](), [chown-command](), [command](), [command-line](), [debian-linux](), [easy](), [files](), [how-to](), [linux](), [permissions](), [redhat-and-friends](), [suse]() ### AI overview A Linux tutorial explains how to copy file permissions and ownership from one file or directory to another using chmod with --reference and chown. It also covers copying access control lists with getfacl and setfacl. ### Source excerpt I need to copy or clone file ownership and permissions from another file on Linux. Is there a bash command line option to clone the user, group ownership and permissions on a file from another file on Linux operating system? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to copy permissions from one file to another on Linux appeared first on nixCraft. ## Getting NuShell Usable Under OSX for Myself DevFeed: [Getting NuShell Usable Under OSX for Myself]() Original publisher: [Read original article]() Author: Fuzzygroup Published: 2022-07-17T15:20:00Z Content type: tutorial Language: en Sources: [Scott Johnson]() Topics: [Shell](), [osx](), [Command-line interface](), [Homebrew](), [Terminal](), [configuration](), [chmod]() Tags: [bash](), [blog-post](), [chmod](), [coding](), [commands](), [config](), [how-to](), [install](), [nushell](), [osx](), [rust](), [shell](), [terminal]() ### AI overview A practical guide to making NuShell usable as a daily shell on OSX Monterey. It covers changing the default shell, preserving Bash history, fixing Homebrew path access, configuring persistent environment settings, and defining aliases. ### Source excerpt Pizza courtesy of Pizza for Ukraine! Donate Now to Pizza for Ukraine As I've written, I'm acutely interested in using software written in Rust as my daily drivers. What I've seen so far is that programs written in Rust, based on an admittedly tiny sample, seem to be higher quality than programs not written in Rust. In this blog post, I'm going to talk about what I had to do to make NuShell be usable for myself under OSX Monterey. To be perfectly honest, I don't know if my experiences are normal or not. I seem to have a high personal level of entropy with respect to software and it appears that at least sometimes this level of entropy causes bugs. This is the main reason that I document things so dogmatically - I often need to refer to my own blog. Step 00: Changing Your Shell to NuShell After you install NuShell, you are left a bit on your own. You can invoke it via the nu command but what you really want is it to come up as the default shell. This is done with chsh: sudo chsh -s /usr/local/bin/nu sjohnson NOTE: DO NOT CLOSE ALL YOUR OLD TERMINALS!!! If you are like me and are heavily reliant on history then you want to do this in an existing Bash / Zshell / Fish / Whatever terminal window: history > ~/history_old.txt chmod +r ~/history_old.txt Yes - I think that strongly about history that I want this read only so it doesn't get killed inadvertently. Step 01: Getting Brew to Function After you switch over to using NuShell, you may find that programs like brew aren't found. This is a path issue (isn't everything???). Here's an example: /Users/sjohnson/Sync/coding/flow_analytics〉brew 07/17/2022 10:59:12 AM Error: nu::shell::external_command (link) x External command ╭─[entry #11:1:1] 1 │ brew - ──┬─ - ╰── can't run executable ╰──── help: No such file or directory (os error 2) The solution is to add brew's path into the NuShell environment. Back in your old shell window, type: Sync/coding/flow_analytics on ☁ (us-west-2) ❯ which brew /usr/local/bin/brew This tells us ## Fixing zsh Compaudit Problem on OSX Catalina DevFeed: [Fixing zsh Compaudit Problem on OSX Catalina]() Original publisher: [Read original article]() Author: Fuzzygroup Published: 2020-06-04T00:00:00Z Content type: tutorial Language: en Sources: [Scott Johnson]() Topics: [Zsh](), [chmod](), [osx](), [Shell]() Tags: [catalina](), [chmod](), [osx](), [shell](), [zsh]() ### AI overview A troubleshooting article about resolving zsh compinit's insecure-directories warning on OSX Catalina. It identifies directory permissions as the issue and gives the command `compaudit | xargs chmod g-w`, reported to fix the problem. ### Source excerpt Ever since OSX Catalina, every time I open a new shell window I get this error: zsh compinit: insecure directories, run compaudit for list. Ignore insecure directories and continue [y] or abort compinit [n]? y (eval):32: command not found: complete The issue with complete isn't the problem here - it is the insecure directories issue. After a bunch of googling, I found this command: compaudit | xargs chmod g-w which fixed the issue entirely. ## Uploading EC2 Logs to S3 on Shutdown DevFeed: [Uploading EC2 Logs to S3 on Shutdown]() Original publisher: [Read original article]() Published: 2018-09-04T08:56:00Z Content type: tutorial Language: en Sources: [Curalate]() Topics: [Amazon EC2](), [Amazon S3](), [Amazon Web Services](), [Linux](), [Bash](), [Ubuntu](), [chmod](), [cURL](), [SIEM, Security, Observability](), [C++]() Tags: [aws](), [bash](), [c-plus-plus](), [chmod](), [curl](), [ec2](), [linux](), [logging](), [logs](), [s3](), [script](), [ubuntu]() ### AI overview This tutorial shows how to use a Linux shutdown script on Ubuntu EC2 instances to upload selected logs to Amazon S3 before an Auto Scaling Group terminates a failed instance. It is intended to preserve evidence for debugging, including errors from C++ code that may bypass JVM or logging services. ### Source excerpt If you've ever used an auto scaling group (ASG) on AWS, you've probably had an EC2 instance fail and get removed from the ASG. While great for redundancy (the ASG launches a new instance to start handling requests), it makes debugging the failure difficult since the ASG terminates the bad instance, erasing any evidence of what went wrong. Below, I present a script that will upload relevant files to S3 after an instance is triggered to shutdown but before it terminates. To achieve this, we make use of Linux's runlevel scripts. The instructions below are for Ubuntu, but it should be straight forward to migrate to a different distro. First, we make a script /etc/rc0.d/K01upload-logs. This script will run when the system is shutting down. You should change BUCKET, PATH, and LOG_FILE to match your needs. #!/bin/bash source /etc/environment # get strict after sourcing environment since we don't trust it... set -euo pipefail IFS=$'\n\t' # what logs should I upload and where to? LOG_FILE="/var/log/tomcat7/catalina.out" BUCKET="my-logs-bucket" # below we include the instance id in the path. That way it's easily findable. HOST=$(/usr/bin/curl http://169.254.169.254/latest/meta-data/instance-id) PATH="services/logs/$HOST/" # upload the logs /bin/echo "Uploading logs to s3://$BUCKET/$PATH" | /usr/bin/wall /usr/local/bin/aws s3 cp $LOG_FILE s3://$BUCKET/$PATH wait After installing the script, you need to set the permissions: chown root:root /etc/rc0.d/K01upload-logs chmod +x /etc/rc0.d/K01upload-logs And that's it! The script will upload the logs to your S3 bucket when the ASG terminates an instance. We've found this extremely helpful for our deep learning infrastructure that can often contain errors from C++ code (and thus isn't handled by the jvm or sent to our logging services). ## Install WordPress from command-line DevFeed: [Install WordPress from command-line]() Original publisher: [Read original article]() Author: Tom Published: 2016-02-15T00:00:00Z Content type: tutorial Language: en Sources: [Tomasz Gągor]() Topics: [WordPress](), [Command-line interface](), [apt](), [chmod](), [cURL](), [MySQL]() Tags: [apt](), [bash](), [chmod](), [cli](), [command-line](), [curl](), [install](), [mysql](), [root](), [wordpress]() ### AI overview A tutorial showing how to install WordPress from the command line using WP-CLI, including prerequisites, downloading the WP-CLI executable, checking it, and installing WordPress as the web application user. ### Source excerpt I never tried it before but today I needed to install WordPress... From command line only. And there is a way to do this with wp-cli external link . WP-CLI installation First some requirements (as root): apt-get install php5-cli php5-mysql mysql-client curl And now installation of wp-cli (as root too): curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar chmod +x wp-cli.phar mv wp-cli.phar /usr/local/bin/wp Check if it's working: ## Linux File Permissions Explained DevFeed: [Linux File Permissions Explained]() Original publisher: [Read original article]() Published: 2011-07-19T00:00:00Z Content type: tutorial Language: en Sources: [Radek Pazdera]() Topics: [Linux](), [Authorization](), [chmod](), [file](), [Unix]() Tags: [chmod](), [command](), [file-permissions](), [linux](), [permissions](), [users]() ### AI overview A tutorial explaining Linux file permissions, including how permission strings identify file types and define read, write, and execute access for owners, groups, and other users. It also introduces changing permissions with chmod and calculating numeric permission values. ### Source excerpt I build software products and write on the Internet.