Sahil Suri, Author at The Linux Juggernaut

Linux zcat command explained

Posted by Sahil Suri | Sep 10, 2018 | Basics |

Introduction File compression plays an important role in the life of a system administrator and a generic operating system user as it helps us in saving disk space by allowing us to store more data within the same chunk of available storage media. The Linux operating system provides more than one utilities which allows us to compress files to save disk space. Some of the popular ones are zip, gzip and bzip. All these utilities are used to compress files with slight differences in the command line options they provide and also the level of compression they provide. The utilities which allow us to compress files also come with complimentary utilities to uncompress the files. But what if we find ourselves in a scenario wherein we need to view the contents of a file without extracting or uncompressing it? In such a situation we can use the zcat command to view the contents of the file without extracting it. In this article we will explain how we can make the best use of the zcat command with some practical examples. The zcat command should be available on your Linux distribution as part of the base installation. [root@linuxnix ~]# yum whatprovides zcat ----------------output truncated for brevity gzip-1.5-10.el7.x86_64 : The GNU data compression program Repo : base Matched from: Filename : /usr/bin/zcat Here is a description of the zcat command available...

Disable Delete Permission For Specific User using vSFTPd server

Posted by Sahil Suri | Aug 30, 2018 | Basics |

Introduction Data security and data integrity are critical for the successful functioning of any enterprise infrastructure. Setting up file servers to transfer files via FTP & SFTP is common practice. Some files being transferred and shared using FTP servers could have very important information like customer and billing data. Accidental deletion of such files could cause a major problem for the system administrator. If the passwords for the accounts being used to access these files get leaked and someone purposefully deletes the files then this could also cause a major issue. In one of our previous articles, we demonstrated how to configure chrooted sftp user accounts wherein the user was not permitted to access any folder outside the realm of it’s own home directory. This is a secure setup and is frequently implemented in organizations across the globe. In this article, we’ll shift our focus back to ftp and show you step by step how you could prevent specific users from deleting any files they might have access to. Step 1: Add the test user For the purpose of this demonstration we’ll be working on a Centos 6.8 system and will use a user account named nixuser to test our setup. So, first we’ll add this user. [root@linuxnix ~]# useradd -s /bin/false nixuser [root@linuxnix ~]# passwd nixuser Changing password for user nixuser. New password: BAD PASSWORD: it is WAY...

Enabling passwordless authentication for chrooted sftp users in Linux

Posted by Sahil Suri | Aug 15, 2018 | Administration, Basics |

Introduction In one of our previous articles we demonstrated how to setup chrooted sftp accounts. You may have certain application users which need to connect to the sftp server to transfer files in an automated manner without manual intervention. An enterprise infrastructure may comprise of many scripts as well which might need to transfer files to the sftp server in an automated fashion without having the need to enter credentials. Configuration of password less authentication for chrooted sftp user accounts is similar to that of ssh user accounts but involves an additional step. In this article we will demonstrate how to setup passwordless authentication for a chrooted sftp user account. In order to make this post easy to follow for our readers and maintain continuity we will setup passwordless sftp authentication for the chrooted sftp user named sahil which we created in our earlier article where we explained the setting up of chrooted sftp users. Step 1: Ensure destination user credentials are working Before we setup passwordless authentication let’s first try to login to the server as the user sahil with it’s password to make sure that the user account is working and has been setup correctly. [root@linuxnix ~]# sftp sahil@linuxnix Connecting to linuxnix... sahil@linuxnix's password: sftp> ls sftp> pwd Remote working directory: /myhome sftp> quit [root@linuxnix ~]# Step 2: Setup ssh keys for the source user For the purpose...

Author: Sahil Suri

Linux zcat command explained

Disable Delete Permission For Specific User using vSFTPd server

Enabling passwordless authentication for chrooted sftp users in Linux

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