{"id":4472,"date":"2013-03-12T00:05:50","date_gmt":"2013-03-11T16:05:50","guid":{"rendered":"https:\/\/webhostinggeeks.com\/howto\/?p=4472"},"modified":"2023-06-25T09:00:45","modified_gmt":"2023-06-25T09:00:45","slug":"7-useful-linux-utilities","status":"publish","type":"post","link":"https:\/\/webhostinggeeks.com\/howto\/7-useful-linux-utilities\/","title":{"rendered":"7 Useful Linux Utilities"},"content":{"rendered":"

When setting up a new Linux server, there are several utilities that can significantly enhance your system’s functionality and ease your troubleshooting process. While most Linux distributions come pre-loaded with a plethora of command utilities, a minimal operating system installation might not include all these tools.<\/p>\n

This guide will walk you through seven essential Linux utilities that you should consider installing on your server. These utilities are equally functional in CentOS or Red Hat Enterprise Linux (RHEL).<\/p>\n

Identifying Missing Utilities<\/h2>\n

Before we delve into the specifics of each utility, it’s important to know how to identify whether a utility is installed on your Linux operating system. If a utility is missing, you’ll see one or more of the following warnings:<\/p>\n

\r\n[root@rhel62 ~]# wget\r\n-bash: wget: command not found\r\n[root@rhel62 ~]# telnet\r\n-bash: telnet: command not found\r\n[root@rhel62 ~]# scp\r\n-bash: scp: command not found\r\n[root@rhel62 ~]# man scp\r\n-bash: man: command not found\r\n[root@rhel62 ~]# nslookup\r\n-bash: nslookup: command not found\r\n[root@rhel62 ~]# dig\r\n-bash: dig: command not found\r\n[root@rhel62 ~]# host\r\n-bash: host: command not found\r\n<\/pre>\n
Seven Essential Linux Utilities<\/h2>\n
Let’s now explore each of these seven utilities in detail.<\/p>\n
1. wget<\/h3>\n
Wget is a network utility that retrieves files from the Web using HTTP and FTP, the two most widely used Internet protocols. It’s a handy tool for downloading files from the internet directly to your server.<\/p>\n
[root@rhel62 ~]# wget http:\/\/files2.zimbra.com\/downloads\/8.0.2_GA\/zcs-8.0.2_GA_5569.RHEL6_64.20121210115059.tgz\r\n<\/pre>\n
2. telnet<\/h3>\n
Telnet is a network protocol used on the Internet or local area networks. It’s a user command and an underlying TCP\/IP protocol for accessing remote computers. Telnet is very useful for troubleshooting and verifying the opened ports.<\/p>\n
[root@rhel62 ~]# telnet localhost 25\r\nTrying ::1...\r\nConnected to localhost.\r\nEscape character is '^]'.\r\n220 rhel62.webhostinggeeks-dev2.local ESMTP Postfix\r\n<\/pre>\n
3. scp<\/h3>\n
Secure Copy Protocol (scp) is a remote file copy utility between hosts on a network. It uses ssh for data transfer and provides the same authentication and same level of security as ssh.<\/p>\n
[root@rhel62 ~]# scp root@192.168.2.60:\/tmp\/VMwareTools-9.2.2-893683.tar.gz .\r\nThe authenticity of host '192.168.2.60 (192.168.2.60)' can't be established.\r\nRSA key fingerprint is 76:78:87:36:44:c1:46:fa:c4:b4:61:4a:e5:b3:be:e3.\r\nAre you sure you want to continue connecting (yes\/no)? yes\r\nWarning: Permanently added '192.168.2.60' (RSA) to the list of known hosts.\r\nroot@192.168.2.60's password:\r\nVMwareTools-9.2.2-893683.tar.gz                                                       100%   63MB  63.3MB\/s   00:01\r\n<\/pre>\n
4. man<\/h3>\n
The ‘man’ command is used to display the manual page for other commands. It helps to explain the functions for the commands that are commonly used.<\/p>\n
Example :<\/p>\n
[root@rhel62 ~]# man wget\r\n<\/pre>\n
WGET(1)                            GNU Wget                            WGET(1)\r\n\r\nNAME\r\n       Wget - The non-interactive network downloader.\r\n\r\nSYNOPSIS\r\n       wget [option]... [URL]...\r\n\r\nDESCRIPTION\r\n       GNU Wget is a free utility for non-interactive download of files from the Web.  It supports HTTP,\r\n       HTTPS, and FTP protocols, as well as retrieval through HTTP proxies.\r\n\r\n       Wget is non-interactive, meaning that it can work in the background, while the user is not logged on.\r\n       This allows you to start a retrieval and disconnect from the system, letting Wget finish the work.\r\n       By contrast, most of the Web browsers require constant user\u00e2s presence, which can be a great\r\n       hindrance when transferring a lot of data.\r\n\r\n       Wget can follow links in HTML, XHTML, and CSS pages, to create local versions of remote web sites,\r\n       fully recreating the directory structure of the original site.  This is sometimes referred to as\r\n       \"recursive downloading.\"  While doing that, Wget respects the Robot Exclusion Standard (\/robots.txt).\r\n       Wget can be instructed to convert the links in downloaded files to point at the local files, for\r\n       offline viewing.\r\n<\/pre>\n
5. nslookup, dig, host<\/h3>\n
These three utilities – nslookup, dig, and host – are part of the bind utilities. They are the basic tools for DNS client and DNS server troubleshooting.<\/p>\n
Examples:<\/p>\n
[root@rhel62 ~]# nslookup\r\n> set type=mx\r\n> webhostinggeeks-dev2.com\r\nServer:         8.8.8.8\r\nAddress:        8.8.8.8#53\r\n\r\nNon-authoritative answer:\r\nwebhostinggeeks-dev2.com   mail exchanger = 0 webhostinggeeks-dev2.com.\r\n\r\nAuthoritative answers can be found from:\r\n>\r\n<\/pre>\n
[root@rhel62 ~]# dig webhostinggeeks-dev2.com\r\n\r\n; < <>> DiG 9.7.3-P3-RedHat-9.7.3-8.P3.el6 < <>> webhostinggeeks-dev2.com\r\n;; global options: +cmd\r\n;; Got answer:\r\n;; ->>HEADER<<\/pre>\n
[root@rhel62 ~]# host -t mx webhostinggeeks-dev2.com\r\nwebhostinggeeks-dev2.com mail is handled by 0 webhostinggeeks-dev2.com.\r\n<\/pre>\n
Installation of Utilities<\/h2>\n
To install these utilities, you can simply run the following command:<\/p>\n
\r\n[root@rhel62 ~]# yum install wget telnet openssh-clients bind-utils man -y\r\n<\/pre>\n
Commands Mentioned<\/h2>\n