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.
10 Answers 10
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:
if you want to have both stderr and output displayed on the console and in a file use this:
SomeCommand 2>&1 | tee SomeFile.txt (If you want the output only, drop the 2 above)
Note that someCommand 2> someFile.txt and someCommand 2>> someFile.txt also redirects stterr to someFile.txt
I’m trying to do this with gcc command but it doesn’t work. It works with other commands, but not this one. It simply creates the output file with nothing inside it.
@Nik-Lz Often this is because the command is sending all its output on stderr. If gcc is generating error messages, this seems likely. See Slothworks comment for how to capture stderr instead of stdout.
NB: to get the output of the make command into a file it requires this syntax instead: make > someFile.txt 2>&1 (source: linuxquestions.org/questions/linux-newbie-8/…)
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.
|| visible in terminal || visible in file || existing Syntax || StdOut | StdErr || StdOut | StdErr || file ==========++==========+==========++==========+==========++=========== > || no | yes || yes | no || overwrite >> || no | yes || yes | no || append || | || | || 2> || yes | no || no | yes || overwrite 2>> || yes | no || no | yes || append || | || | || &> || no | no || yes | yes || overwrite &>> || no | no || yes | yes || append || | || | || | tee || yes | yes || yes | no || overwrite | tee -a || yes | yes || yes | no || append || | || | || n.e. (*) || yes | yes || no | yes || overwrite n.e. (*) || yes | yes || no | yes || append || | || | || |& tee || yes | yes || yes | yes || overwrite |& tee -a || yes | yes || yes | yes || append List:
- command > output.txt 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.
- command >> output.txt 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.
- command &> output.txt 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.
- command &>> output.txt 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.
Save all the terminal output to a file
Many GUI terminal emulators allow to save the scroll buffer, but this is not accessible to commands (leaving aside xdotool and this sort of black art).
4 Answers 4
You can use script . It will basically save everything printed on the terminal in that script session.
script makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1). You can start a script session by just typing script in the terminal, all the subsequent commands and their outputs will all be saved in a file named typescript in the current directory. You can save the result to a different file too by just starting script like:
To logout of the script session (stop saving the contents), just type exit .
$ script output.txt Script started, file is output.txt $ ls output.txt testfile.txt foo.txt $ exit exit Script done, file is output.txt $ cat output.txt Script started on Mon 20 Apr 2015 08:00:14 AM BDT $ ls output.txt testfile.txt foo.txt $ exit exit Script done on Mon 20 Apr 2015 08:00:21 AM BDT script also has many options e.g. running quietly -q ( —quiet ) without showing/saving program messages, it can also run a specific command -c ( —command ) rather than a session, it also has many other options. Check man script to get more ideas.
Can it be invoked after the fact? (i.e. At the end of a session) Or does it have to be invoked before the content you want logged?
To export it retroactively, try Terminal menu -> Shell -> Export text as, like here: mactricksandtips.com/2013/04/save-terminals-text-output.html
@Magne you should note in your comment that it is specific to the terminal utility in Mac. gnome-terminal, for one, does not have that menu, so we should assume that other linux terminal windows won’t have it either.
I too faced the same problem and after some search came up with this solution:
Add to your .bash_aliases this:
# Execute "script" command just once smart_script() < # if there's no SCRIPT_LOG_FILE exported yet if [ -z "$SCRIPT_LOG_FILE" ]; then # make folder paths logdirparent=~/Terminal_typescripts logdirraw=raw/$(date +%F) logdir=$logdirparent/$logdirraw logfile=$logdir/$(date +%F_%T).$$.rawlog # if no folder exist - make one if [ ! -d $logdir ]; then mkdir -p $logdir fi export SCRIPT_LOG_FILE=$logfile export SCRIPT_LOG_PARENT_FOLDER=$logdirparent # quiet output if no args are passed if [ ! -z "$1" ]; then script -f $logfile else script -f -q $logfile fi exit fi ># Start logging into new file alias startnewlog='unset SCRIPT_LOG_FILE && smart_script -v' # Manually saves current log file: $ savelog logname savelog() < # make folder path manualdir=$SCRIPT_LOG_PARENT_FOLDER/manual # if no folder exists - make one if [ ! -d $manualdir ]; then mkdir -p $manualdir fi # make log name logname=$logname=$ # add user logname if passed as argument if [ ! -z $1 ]; then logname=$logname'_'$1 fi # make filepaths txtfile=$manualdir/$logname'.txt' rawfile=$manualdir/$logname'.rawlog' # make .rawlog readable and save it to .txt file cat $SCRIPT_LOG_FILE | perl -pe 's/\e([^\[\]]|\[.*?[a-zA-Z]|\].*?\a)//g' | col -b > $txtfile # copy corresponding .rawfile cp $SCRIPT_LOG_FILE $rawfile printf 'Saved logs:\n '$txtfile'\n '$rawfile'\n' > And to the end of your .bashrc file add this:
After you’ve done this, «script» command will be executed once in every terminal session, logging everything to ~/Terminal_typescripts/raw .
If you want, you can save current session log after the fact (in the end of the session) by typing savelog or savelog logname – this will copy current raw log to ~/Terminal_typescripts/manual and also create readable .txt log in this folder. (If you forget to do so, raw log files will still be in their folder; you’ll just have to find them.) Also you may start recording to a new log file by typing startnewlog .
There will be a lot of junk log files, but you can clean old ones from time to time, so it’s not a big problem.
Redirect all output to file in Bash [duplicate]
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. Is there a way to redirect all output to file?
9 Answers 9
That part is written to stderr, use 2> to redirect it. For example:
foo > stdout.txt 2> stderr.txt or if you want in same file:
Note: this works in (ba)sh, check your shell for proper syntax
well, i found the reference and have deleted my post for having incorrect information. from the bash manual: ‘»ls 2>&1 > dirlist» directs only the standard output to dirlist, because the standard error was duplicated from the standard output before the standard output was redirected to dirlist» 🙂
also from the bash man «There are two formats for redirecting standard output and standard error: &>word and >&word Of the two forms, the first is preferred. This is semantically equivalent to >word 2>&1»
Two important addenda: If you want to pipe both stdout and stderr, you have to write the redirections in the opposite order from what works for files, cmd1 2>&1 | cmd2 ; putting the 2>&1 after the | will redirect stderr for cmd2 instead. If both stdout and stderr are redirected, a program can still access the terminal (if any) by opening /dev/tty ; this is normally done only for password prompts (e.g. by ssh ). If you need to redirect that too, the shell cannot help you, but expect can.
All POSIX operating systems have 3 streams: stdin, stdout, and stderr. stdin is the input, which can accept the stdout or stderr. stdout is the primary output, which is redirected with > , >> , or | . stderr is the error output, which is handled separately so that any exceptions do not get passed to a command or written to a file that it might break; normally, this is sent to a log of some kind, or dumped directly, even when the stdout is redirected. To redirect both to the same place, use:
EDIT: thanks to Zack for pointing out that the above solution is not portable—use instead:
If you want to silence the error, do:
Linux All Output to a File
Is there any way to tell Linux system put all output(stdout,stderr) to a file? With out using redirection, pipe or modification the how scrips get called. Just tell the Linux use a file for output. for example: script test1.sh:
If i run it like «./test1.sh» (with out redirection or pipe) i’d like to see «Testing 123» in a file (/tmp/linux_output) Problem: in the system a binary makes a call to a script and this script call many other scrips. it is not possible to modify each call so If i can modify Linux put «output» to a file i can review the logs.
4 Answers 4
#!/bin/bash exec >file 2>&1 echo "Testing 123 " You can read more about exec here
This is require to modification the scrips. I’m looking regardless of what script or application run put out put to a file not to a console screen
@FCa, no, this doesn’t require modifying the script, because you can do this in an intermediate script.
If you are running the program from a terminal, you can use the command script. It will open up a sub-shell. Do what you need to do. It will copy all output to the terminal into a file. When you are done, exit the shell. ^D, or exit. This does not use redirection or pipes.
You could set your terminal’s scrollback buffer to a large number of lines and then see all the output from your commands in the buffer — depending on your terminal window and the options in its menus, there may be an option in there to capture terminal I/O to a file.
Your requirement if taken literally is an impractical one, because it is based in a slight misunderstanding. Fundamentally, to get the output to go in a file, you will have to change something to direct it there — which would violate your literal constraint.
But the practical problem is solvable, because unless explicitly counteracted in the child, the output directions configured in a parent process will be inherited. So you only have to setup the redirection once, using either a shell, or a custom launcher program or intermediary. After that it will be inherited.
#/bin/sh echo "hello on stdout" rm nosuchfile ./test2.sh And a child script for it to call
#/bin/sh echo "hello on stdout from script 2" rm thisfileisnteither ./nonexistantscript.sh Run the first script redirecting both stdout and stderr (bash version — and you can do this in many ways such as by writing a C program that redirects its outputs then exec()’s your real program)
Now examine the file and see results from stdout and stderr of both parent and child.
hello on stdout rm: nosuchfile: No such file or directory hello on stdout from script 2 rm: thisfileisnteither: No such file or directory ./test2.sh: line 4: ./nonexistantscript.sh: No such file or directory Of course if you really dislike this, you can always always modify the kernel — but again, that is changing something (and a very ungainly solution too).