William Stanek - Essential Windows Xp Commands Reference

A command consists of a command name followed by any required or optional arguments. Arguments include parameters used to pass information needed by the command and switches used to control the way the command works as well as modifiers that change the behavior of a switch. Command names and arguments are always separated by spaces. Here is an example: dir /s c:\data In this example, dir is the command that you want to execute, /s is a command switch, and c:\data is a command parameter. As you work with commands, you'll notice that some commands have only one style of use (or syntax), while others have multiple uses (or syntaxes). Command Redirection Normally, shell commands take input from the parameters and switches specified when the commands are called and send their output to the standard console window.

If you want to change this behavior, you can redirect input and output if necessary. For example, you can take input from a different source or send output to a file or other output device. Redirection techniques you can use and their syntaxes include: Most shell commands generate output that can be redirected. You redirect command output using the pipe symbol (|), such as: ftype | sort | more The < redirection symbol enables you to specify a file as input for a command, such as: sort < details.txt The > redirection symbol sends command output to a file overwriting any existing data, such as: ver > os.txt To append output to an existing, use the >> redirection symbol, such as: pathping >> pingdata.txt Redirecting Errors Normally, errors are output to the command shell. If necessary, you can redirect error output to a file using the 2> redirection symbol, such as: netstat r 2> errors.txt To redirect standard error to the same destination as command output, use the 2>&1 redirection symbol, such as: netstat r > data.txt 2>&1 You can also send output to devices, such as a printer. Here is an example: ipconfig > lpt1 I/O devices you can use with the command shell include: Chaining and Grouping Commands You can chain commands together or have certain commands execute only if earlier commands succeed (or fail).

When you use multiple commands together, you reate a compound command. The syntax for compound commands is: