Linux save all commands

How to Save Command Output to a File in Linux

There are many things you can do with the output of a command in Linux. You can assign the output of a command to a variable, send it to another command/program for processing through a pipe or redirect it to a file for further analysis.

In this short article, I will show you a simple but useful command-line trick: how to view output of a command on the screen and also write to a file in Linux.

Viewing Output On Screen and also Writing to a File

Assuming you want to get a full summary of available and used disk space of a file system on a Linux system, you can employ the df command; it also helps you determine the file system type on a partition.

Check Filesystem Disk Space

With the -h flag, you can show the file system disk space statistics in a “human readable” format (displays statistics details in bytes, mega bytes and gigabyte).

Disk Space in Human Readable Format

Now to display the above information on the screen and also write it to a file, say for later analysis and/or send to a system administrator via email, run the command below.

Linux Command Output to File

Here, the magic is done by the tee command, it reads from standard input and writes to standard output as well as files.

If a file(s) already exists, you can append it using the -a or —append option like this.

Note: You can also use pydf an alternative “df” command to check disk usage in different colors.

For more information, read through the df and tee man pages.

You may also like to read similar articles.

In this short article, I showed you how to view output of a command on the screen and also write to a file in Linux. If you have any questions or additional ideas to share, do that via the comment section below.

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How To Save Linux Commands And Use Them On Demand

Let us say you’re searching for a particular command to solve a specific issue on your Linux system. After a bit of web search, you found the solution to fix the issue. After a few weeks or months, you encountered with the same issue on another Linux system. You remember solving the same issue a few weeks ago, but you completely forgot the full command. You do reverse search on your Terminal by pressing ‘CTRL+R’ from the Terminal, and you search through your browser history. But your mind has completely gone blank and you couldn’t recall the exact command. I don’t know if it ever happened to you, but I have faced this issue a few times. Every time, I had to spend a lot of time on the web to search for commands. Not any more! Say hello to ‘Keep’, a personal shell command keeper to save Linux commands and use them whenever you want.

As the name says, the ‘Keep’ utility allows you to keep the most frequently used and most important Linux commands and you can use them later without having to search on websites or man pages. Also, you don’t need to memorize the lengthy and complex commands. Keep utility will save your important and frequently used commands in Terminal itself. You can retrieve and execute them at any time. More importantly, you can sync the saved commands across multiple systems and also save all commands on a remote system.

To put this simply, ‘Keep’ utility,

• can keep all your commands with brief description,
• allows you to search the saved commands using powerful patterns,
• allows you to sync saved commands on multiple systems on the network,
• allows you to save commands on any remote server on the network.

In this brief guide, I will show you how to install and use ‘Keep’ in Linux and Unix-like systems.

Install ‘Keep’ On Linux

The easiest and official way to install ‘Keep’ is by using Pip. Pip is a package manager that allows you to install applications written using Python programming language.

Pip can be installed on Arch Linux and its derivatives as shown below:

On Debian, Ubuntu, Linux Mint:

On RHEL, Fedora, CentOS:

Enable EPEL repository first.

Then, install pip using command:

Once pip installed, run the following command to install ‘Keep’. The following command is same for all Linux distributions!

Save Linux Commands In Terminal And Use Them On Demand Using ‘Keep’ Utility

‘Keep’ usage is very simple. The typical syntax of ‘keep’ utility is:

Let me show you a few practical examples.

Have a look at the following command:

This command will find and copy all files that ends with extension .txt and save them in «/home/sk/Downloads/» directory. I am very poor at remembering things. After a couple days, I might forget this command. I bet some of you can’t remember this kind of lengthy commands after some time.

So, what I am going to do is just save this command in my Terminal using ‘keep’ utility.

First, we need to initialize the ‘keep’ environment.

The above command will ask you to enter your Email. It is the unique username to you. You can input anything unique to you. You can also choose not to register this time and later start the process by using keep register command. If you do not intend to use the server for storing or fetching your commands, just ignore the registration. It generates a 255 bit password for you. It is then stored inside your

Sample output would be:

Save a new command

To save a new command, just run:

Enter the full command you’d like to save and hit ENTER. Then, provide the description of the command and press ENTER key.

Sample output:

Now, the command has been saved. Similarly, you can save any number of commands using ‘keep new’ command.

View the saved commands

To view all saved commands, just run:

This command will display the list of saved commands with description.

Sample output:

Search for the saved commands

You can search any saved commands with its description. You don’t have to specify the complete description. Look at the following example.

You will see the saved commands matching to the search term. I got the following command output when running the above command:

Execute the saved commands

To execute the saved commands at any time, simply run with saved command’s description as shown below:

You will be asked whether to execute or not the command. Just press ‘Y’ to run the command:

Sync Saved commands with another system

If you have another system, install ‘keep’ on it as I described in the «Install Keep» section. Then, run «keep init» (without quotes, of course) command and skip registration. Copy your

/.keep/.credentials file over to the target computer in the same location. Finally, run the following command to retrieve all the saved commands.

To store the commands on the remote server, use ‘keep push’ command.

Delete saved commands

To delete a saved command, simply run:

Enter the command to remove and hit ENTER. The specified command will deleted from the Keep cache.

For more details, run:

Suggested Read:

Conclusion

‘Keep’ utility is really useful when it comes to dealing with numerous commands everyday. It is quite difficult to remember all commands. In such cases, Keep utility might be useful.

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How do I get a list of all available shell commands

In a typical Linux shell (bash) it is possible to to hit tab twice, to get a list of all available shell commands.

Is there a command which has the same behaviour? I want to pipe it into grep and search it.

10 Answers 10

You could use compgen. For example:

You also could grep it, like this:

You can list the directories straight from $PATH if you tweak the field separator first. The parens limit the effect to the one command, so use: (. ) | grep .

«tab» twice & «y» prints all files in the paths of $PATH. So just printing all files in PATH is sufficient.

Just type this in the shell:

This redirect all the commands to a file «my_commands».

List all the files in your PATH variable (ls all the directories in the PATH). The default user and system commands will be in /bin and /sbin respectively but on installing some software we will add them to some directory and link it using PATH variable.

There may be things on your path which aren’t actually executable.

This will also print paths, of course. If you only want unqualified filenames, it should be easy to adapt this.

Funny, StackOverflow doesn’t know how to handle syntax highlighting for this. 🙂

Similar to @ghoti, but using find:

Bash uses a builtin command named ‘complete’ to implement the tab feature.

I don’t have the details to hand, but the should tell you all you need to know:

It doesn’t include shell builtins though.

An answer got deleted, I liked it most, so I’m trying to repost it:

compgen is of course better

I found this to be the most typical shell thing, I think it works also with other shells (which I doubt with things like IFS=’:’ )

Clearly, there maybe problems, if the file is not an executable, but I think for my question, that is enough — I just want to grep my output — which means searching for some commands.

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View history of commands run in terminal

Is there a way to save all my typed terminal commands and view it like history in a log book?

5 Answers 5

This is automatically done. Bash stores your commands in

/.bash_history . If you want to have a look at the history, either print the output of this file using one of

Or you can use bash’s builtin command:

To clear the history, delete the file and clear the temp history:

The history size defaults to 500 commands. You can, however, increase this by adding a line to your

/.bashrc file to set the HISTSIZE variable:

This will not take effect immediately, but only to newly started sessions. To apply this, re-source the .bashrc file:

or run HISTSIZE=. in your current session.

You can type history on a terminal to view all the previous executed commands.

You can truncate the output to some lines (where 5 is the number of lines):

If do you want to view only commands containing a string (i.e. mv ), you can do this:

You can recall a command by typing ! followed by the entry number.

Let’s say that I have a history like this:

• To run mkdir foo , you can type !2 .
• To run the last command, you can use !-1 or !!
• To run the penultimate, you can use !-2

If you run a command that fails because it needs root privileges (i.e. touch /etc/foo ), you can use sudo !! to run the last command as root.

• If you type !man you will execute the last command that begins with man
• If do you type !?man? it will execute the last command that contains man (not neccessarily at the line begin)

If do you have a typo in a command, you can fix it this way. Let’s say that I type cat .bash_hi , to replace .bash_hi by .bash_history I only need to type ^hi^history^ .

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How do I save terminal output to a file?

How do I save the output of a command to a file?

Is there a way without using any software? I would like to know how.

9 Answers 9

Yes it is possible, just redirect the output (AKA stdout ) to a file:

Or if you want to append data:

If you want stderr as well use this:

or this to append:

if you want to have both stderr and output displayed on the console and in a file use this:

(If you want the output only, drop the 2 above)

To write the output of a command to a file, there are basically 10 commonly used ways.

Overview:

_{Please note that the n.e. in the syntax column means «not existing».
There is a way, but it’s too complicated to fit into the column. You can find a helpful link in the List section about it.}

The standard output stream will be redirected to the file only, it will not be visible in the terminal. If the file already exists, it gets overwritten.

The standard output stream will be redirected to the file only, it will not be visible in the terminal. If the file already exists, the new data will get appended to the end of the file.

command 2> output.txt

The standard error stream will be redirected to the file only, it will not be visible in the terminal. If the file already exists, it gets overwritten.

command 2>> output.txt

The standard error stream will be redirected to the file only, it will not be visible in the terminal. If the file already exists, the new data will get appended to the end of the file.

Both the standard output and standard error stream will be redirected to the file only, nothing will be visible in the terminal. If the file already exists, it gets overwritten.

Both the standard output and standard error stream will be redirected to the file only, nothing will be visible in the terminal. If the file already exists, the new data will get appended to the end of the file..

command | tee output.txt

The standard output stream will be copied to the file, it will still be visible in the terminal. If the file already exists, it gets overwritten.

command | tee -a output.txt

The standard output stream will be copied to the file, it will still be visible in the terminal. If the file already exists, the new data will get appended to the end of the file.

Bash has no shorthand syntax that allows piping only StdErr to a second command, which would be needed here in combination with tee again to complete the table. If you really need something like that, please look at «How to pipe stderr, and not stdout?» on Stack Overflow for some ways how this can be done e.g. by swapping streams or using process substitution.

command |& tee output.txt

Both the standard output and standard error streams will be copied to the file while still being visible in the terminal. If the file already exists, it gets overwritten.

command |& tee -a output.txt

Both the standard output and standard error streams will be copied to the file while still being visible in the terminal. If the file already exists, the new data will get appended to the end of the file.

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