How to redirect the output of an entire shell script?

How to redirect the output of an entire shell script?

Redirecting the output of a single command is easy, but I want something more like this: #!/bin/sh if [ ! -t 0 ]; then # redirect all of my output to a file here fi # rest of script… Meaning: if the script is run non-interactively (for example, cron), save off the output of everything to a file.

How to stop exec 1 > file in Linux?

The first exec copies the original file descriptor 1 (standard output) to file descriptor 3, then redirects standard output to the named file. The second exec copies file descriptor 3 to standard output again, and then closes file descriptor 3.

How to recover standard output after exec 1?

You have to prepare for the recovery before you do the initial exec: To recover the original standard output later: The first exec copies the original file descriptor 1 (standard output) to file descriptor 3, then redirects standard output to the named file.

Which is the correct way to use exec 1 file?

Q2: exec 1>file is a slightly more verbose way of doing exec >file which, as already stated, redirect stdout to the given file, provided you have the right to create/write it. The file is created if it doesn’t exist, it is truncated if it does. exec 1>&- is closing stdout, which is probably a bad idea in most situations.

How to redirect output from the screen to a file?

Closed 5 years ago. I know that in Linux, to redirect output from the screen to a file, I can either use the > or tee. However, I’m not sure why part of the output is still output to the screen and not written to the file.

How to redirect output to a device in Linux?

Detail description of redirection operator in Unix/Linux. The > operator redirects the output usually to a file but it can be to a device. You can also use >> to append.

What are the relevant sections of the Bash manual?

The relevant sections of the Bash manual are Grouping Commands and I/O Redirection. The relevant sections of the POSIX shell specification are Compound Commands and I/O Redirection.

How to produce the output of a script?

Then, running the command with ./script.sh abc.txt will produce the output of the date command to the terminal as well as the file abc.txt In your case, exec 2>&1 | tee /home/logging/”$1″ should correctly produce the results you want, but you will need to call the script with that argument carefully.

How to redirect stdout and stderr to terminal?

Then I am having logs on the redirected file but not on the console. to redirect both stdout and stderr to a file as as well as show it in terminal. The purpose of the tee command is specifically intended to direct the output to both a file and to the terminal, which is what it sounds like you’re wanting.

How to redirect stdout to file in Linux?

Then I am getting logs only on console not on the redirected file. Then I am having logs on the redirected file but not on the console. to redirect both stdout and stderr to a file as as well as show it in terminal.

What’s the best way to redirect in JavaScript?

In most cases, the replace () function might be the best option as it won’t cause redirect loops when users hit the browser’s back button. Some browsers and most web crawlers may not execute JavaScript for various reasons, which is why having a fallback in place is a good idea.

Where do I put the code to redirect to?

Therefore, placing the code in the section of the web page should execute the code immediately and redirect in the specified number of miliseconds.

Is it bad to redirect from one page to another?

If a page redirects too quickly (i.e. in less than 2-3 seconds), it can break the Back button on the browser as each time you move back to the redirecting page, redirection will occur again almost immediately. This is especially bad in terms of usability as it can trap the user on the page he was redirected to.

Why does Bash edit script while it’s running?

That demonstrates that bash is, indeed, interpreting the script “as you go”. Indeed, editing a long-running script has unpredictable results, inserting random characters etc. Why? Because bash reads from the last byte position, so editing shifts the location of the current character being read.

How to turn off shell commands in Bash?

Use set +x and set +v to turn off the above settings. On the first line of the script, one can put #!/bin/sh -x (or -v) to have the same effect as set -x (or -v) later in the script.

Is there a way to echo commands in Bash?

You can execute a Bash script in debug mode with the -x option. This will echo all the commands. You can also save the -x option in the script. Just specify the -x option in the shebang.

How to redirect the output of two commands?

How can i make the output of both commands be directed into the same file. Either use ‘append’ with >> or use braces to encompass the I/O redirections, or (occasionally) use exec:

How to redirect output to multiple log files?

The shell connects the command’s stdout to a process that pipes to multiple files; therefore, there isn’t any compelling technical advantage to doing it this way (but it does look real good). See the zsh manual for more. Could be simplified to this, when dealing with many files.

How to redirect the output of an already running process?

The command bellow redirects the outputs (standard and error) of the process PID to FILE: The README of reredirect also explains other interesting features: how to restore the original state of the process, how to redirect to another command or to redirect only stdout or stderr.

How to redirect output from command to variable?

The database restore operation completed successfully. D.J.’s helpful answer shows the most straightforward way to capture any command’s (success) output in a variable – by direct assignment.

Is there a way to redirect PowerShell output to a text file?

By default, PowerShell sends output to the PowerShell host. Usually this is the console application. However, you can direct the output to a text file, and you can redirect error output to the regular output stream. Use the Out-File cmdlet, which sends command output to a text file.

How to redirect output to a descriptor?

Thus only stdout is pointing at the file, because stderr is pointing to the “old” stdout. Another common use for redirecting output is redirecting only stderr. To redirect a file descriptor, we use N>, where N is a file descriptor.

How to redirect stderr to null in shell?

If there’s no file descriptor, then stdout is used, like in echo hello > new-file. We can use this new syntax to silence stderr by redirecting it to /dev/null , which happily swallows whatever it receives and does nothing with it.

How to create a shell script in Linux?

Create a file using a vi editor (or any other editor). Name script file with extension .sh. Start the script with #! /bin/sh. Write some code. Save the script file as filename.sh. For executing the script type bash filename.sh. “#!”. is an operator called shebang which directs the script to the interpreter location.