Which of the following commands can be used with output redirection?
Table of Contents
Which of the following commands can be used with output redirection?
Each stream uses redirection commands. Single bracket ‘>’ or double bracket ‘>>’ can be used to redirect standard output. If the target file doesn’t exist, a new file with the same name will be created.
How do I redirect stdout to a file in Unix?
2 Answers
- Redirect stdout to one file and stderr to another file: command > out 2>error.
- Redirect stdout to a file ( >out ), and then redirect stderr to stdout ( 2>&1 ): command >out 2>&1.
What is the redirect command in Linux?
What is Redirection? Redirection is a feature in Linux such that when executing a command, you can change the standard input/output devices. The basic workflow of any Linux command is that it takes an input and give an output. The standard input (stdin) device is the keyboard.
How do I redirect stdout to a file in Linux?
Redirecting stdout and stderr to a file: The I/O streams can be redirected by putting the n> operator in use, where n is the file descriptor number. For redirecting stdout, we use “1>” and for stderr, “2>” is added as an operator.
How do I redirect the output of a command in Linux?
To use bash redirection, you run a command, specify the > or >> operator, and then provide the path of a file you want the output redirected to. > redirects the output of a command to a file, replacing the existing contents of the file.
Which of the following commands redirects its standard output to the file stdout and redirects its standard error to the file stderr?
Conclusion
| Operator | Description |
|---|---|
| command>filename | Redirect stdout to file “filename.” |
| command>>filename | Redirect and append stdout to file “filename.” |
| command 2>filename | Redirect stderr to file “filename.” |
| command 2>>filename | Redirect and append stderr to file “filename.” |
How do I add stdout to a file?
1 Answer
- Either use this construct: cmd >>file. txt 2>&1 where >> file appends the output to the file and 2>&1 redirects the stderr to stdout .
- Or use cmd &>>file ensuring that you have bash version >4 (using bash –version ) and #!/bin/bash at the beginning of file ( #!/bin/sh won’t work).
What is I O redirection in shell commands?
One of the most important and interesting topics under Linux administration is I/O redirection. This feature of the command line enables you to redirect the input and/or output of commands from and/or to files, or join multiple commands together using pipes to form what is known as a “command pipeline”.
What is the use of redirection commands?
Command Line Redirection On a command line, redirection is the process of using the input/output of a file or command to use it as an input for another file. It is similar but different from pipes, as it allows reading/writing from files instead of only commands.