Linux

script’s return value is stored in the environment variable represented by $?: echo $?

Explain the features and capabilities of bash shell scripting. Know the basic syntax of scripting statements. Be famailiar with various methods and constructs used. Test for properties and existence of files and other objects. Use conditional statements, such as if-then-else blocks. Perform arithmetic operations using scripting language.

FTP (File Transfer Protocol) FTP is a well-known and popular method for transferring files between computers using the internet. This method is built on a client-server model. one of the oldest method of network data transfer, dating back to the early 1970s. As such, it is considered inadequate for modern needs, as well as begin intrinsically insecure. However, it is still in use and when security is not a concern (such as with so-called anonymous FTP) it can make sense....

wget Large file downloads Recursive downloads, where a web page refers to other web pages and all are downloaded at once Password-required downloads Multiple file downloads curl Besides downloading, you may want to obtain information about a URL, such as the source code being used. curl can be used from the command line or a script to read such information.

more networking tools ethtool Queries network interfaces and can also set various parameters such as the speed netstat option r is for active connection nmap scans open ports on a networks; important for security analysis tcpdump dumps network traffic for anaysis iptraf monitors network traffic in text mode mtr combines functionality of ping and traceroute and gives a continuously updated display dig Tests DNS workings;a good replacement for host and nslookup