loop in unix / linux

a loop is a program that has powerful features, allowing you to repeat a set of commands. in this chapter, you will learn through practical examples of loops contained in shell programs.

The while loop in Shell

the while loop gives you the ability to execute a set of repetitive commands until certain conditions occur. it is often used when you need to manipulate iterative variable values.

For loop in Shell

the for loop works on lists of items (items). it repeats a set of commands for each item in a list.

the while loop is perfect for the situation where you want to execute a set of commands while some conditions are true. sometimes you need to execute a set of commands until a condition is true, then you need to use a until loop.

Select loop in Shell

the select loop provides an easy way to create a numbered menu from which the user can select. it is useful when you want to ask the user to select one or more items from a list of options.

The while loop in Shell

the while loop gives you the ability to execute a set of repetitive commands until certain conditions occur. it is often used when you need to manipulate iterative variable values.

Control loop in Unix / Linux

the previous chapter has been shown how to create loops and work with them to perform various tasks. sometimes you need to stop a loop or continue their repetitive process.

Loop in Unix / Linux

a loop is a program that has powerful features, allowing you to repeat a set of commands. in this chapter, you will learn through practical examples of loops contained in shell programs.

For loop in Shell

the for loop works on lists of items (items). it repeats a set of commands for each item in a list.

Select loop in Shell

the select loop provides an easy way to create a numbered menu from which the user can select. it is useful when you want to ask the user to select one or more items from a list of options.

Until loop in Shell

the while loop is perfect for the situation where you want to execute a set of commands while some conditions are true. sometimes you need to execute a set of commands until a condition is true, then you need to use a until loop.

Network communication utilities in Unix / Linux

when you work in a distribution environment then you need to communicate with remote users and you also need access to remote unix devices.

System log in Unix / Linux

unix systems have a very powerful and flexible logging system, which gives you the ability to record almost anything you can imagine and then manipulate this log to track the information you require.

What is Unix / Linux?

unix operating system is a collection of programs that act as a link between a computer and a user.

Useful commands in Unix / Linux

this chapter lists the commands, including syntax and brief descriptions. for more details about these commands, you use.

Instructions for installing Unix / Linux

an important unix concept is the environment, which is defined by environment variables. some are set up by the system, others are set up by you, by the shell or any program you download.

File Management in Unix / Linux

all data in unix is organized in files. all files are organized in folders. these directories are organized in a tree structure that is called the file system.

Signal and Trap in Unix / Linux

signals are software interrupt signals that are sent to a program that indicates a serious event has occurred. these events can be very diverse from user requests to illegal memory access. some signals, like signal interrupts, indicate that a user has asked the program to do something without