I have a bash script, which uses expect package to ssh into a remote server.
My script looks like this:
#!/bin/bash
while getopts "p:" option; do
case "${option}" in
p) PASSWORD=${OPTARG};;
esac
done
/usr/bin/expect -c "
spawn ssh my.login.server.com
expect {
\"Password*\" {
send \"$PASSWORD\r\"
}
}
interact
"
I run it like ./login.sh -p <my-confidential-password>
Now once you run it and log in successfully and exit from the remote server, I can hit up-arrow-key from the keyboard and can still see my command with password in the terminal. Or I simply run history it shows up. Once I exit the terminal, then it also appears in bash_history.
I need something within my script that could clear it from history and leave no trace of the command I ran (or password) anywhere.
I have tried:
Clearing it using history -c && history -r, this doesn't work as the script creates its own session.
Also, echo $HISTCMD returns 1 within script, hence I cannot clear using history -d <tag>.
P.S. I am using macOS
You could disable command history for a command:
set +o history
echo "$PASSWORD"
set -o history
Or, if your HISTCONTROL Bash variable includes ignorespace, you can indent the command with a space and it won't be added to the history:
$ HISTCONTROL=ignorespace
$ echo "Hi"
Hi
$ echo "Invisible" # Extra leading space!
Invisible
$ history | tail -n2
7 echo "Hi"
8 history | tail -n2
Notice that this isn't secure, either: the password would still be visible in any place showing running processes (such as top and friends). Consider reading it from a file with 400 permissions, or use something like pass.
You could also wrap the call into a helper function that prompts for the password, so the call containing the password wouldn't make it into command history:
runwithpw() {
IFS= read -rp 'Password: ' pass
./login.sh -p "$pass"
}
In reference to https://stackoverflow.com/a/11886837/1996022 (also shamelessly stole the title) where the question is how to capture the script's output I would like to know how I can additionally capture the scripts input. Mainly so scripts that also have user input produce complete logs.
I tried things like
exec 3< <(tee -ia foo.log <&3)
exec <&3 <(tee -ia foo.log <&3)
But nothing seems to work. I'm probably just missing something.
Maybe it'd be easier to use the script command? You could either have your users run the script with script directly, or do something kind of funky like this:
#!/bin/bash
main() {
read -r -p "Input string: "
echo "User input: $REPLY"
}
if [ "$1" = "--log" ]; then
# If the first argument is "--log", shift the arg
# out and run main
shift
main "$#"
else
# If run without log, re-run this script within a
# script command so all script I/O is logged
script -q -c "$0 --log $*" test.log
fi
Unfortunately, you can't pass a function to script -c which is why the double-call is necessary in this method.
If it's acceptable to have two scripts, you could also have a user-facing script that just calls the non-user-facing script with script:
script_for_users.sh
--------------------
#!/bin/sh
script -q -c "/path/to/real_script.sh" <log path>
real_script.sh
---------------
#!/bin/sh
<Normal business logic>
It's simpler:
#! /bin/bash
tee ~/log | your_script
The wonderful thing is your_script can be a function, command or a {} command block!
This question already has answers here:
how do i start commands in new terminals in BASH script
(2 answers)
Closed 20 days ago.
So i want to open a new terminal in bash and execute a command with arguments.
As long as I only take something like ls as command it works fine, but when I take something like route -n , so a command with arguments, it doesnt work.
The code:
gnome-terminal --window-with-profile=Bash -e whoami #WORKS
gnome-terminal --window-with-profile=Bash -e route -n #DOESNT WORK
I already tried putting "" around the command and all that but it still doesnt work
You can start a new terminal with a command using the following:
gnome-terminal --window-with-profile=Bash -- \
bash -c "<command>"
To continue the terminal with the normal bash profile, add exec bash:
gnome-terminal --window-with-profile=Bash -- \
bash -c "<command>; exec bash"
Here's how to create a Here document and pass it as the command:
cmd="$(printf '%s\n' 'wc -w <<-EOF
First line of Here document.
Second line.
The output of this command will be '15'.
EOF' 'exec bash')"
xterm -e bash -c "${cmd}"
To open a new terminal and run an initial command with a script, add the following in a script:
nohup xterm -e bash -c "$(printf '%s\nexec bash' "$*")" &>/dev/null &
When $* is quoted, it expands the arguments to a single word, with each separated by the first character of IFS. nohup and &>/dev/null & are used only to allow the terminal to run in the background.
Try this:
gnome-terminal --window-with-profile=Bash -e 'bash -c "route -n; read"'
The final read prevents the window from closing after execution of the previous commands. It will close when you press a key.
If you want to experience headaches, you can try with more quote nesting:
gnome-terminal --window-with-profile=Bash \
-e 'bash -c "route -n; read -p '"'Press a key...'"'"'
(In the following examples there is no final read. Let’s suppose we fixed that in the profile.)
If you want to print an empty line and enjoy multi-level escaping too:
gnome-terminal --window-with-profile=Bash \
-e 'bash -c "printf \\\\n; route -n"'
The same, with another quoting style:
gnome-terminal --window-with-profile=Bash \
-e 'bash -c '\''printf "\n"; route -n'\'
Variables are expanded in double quotes, not single quotes, so if you want them expanded you need to ensure that the outermost quotes are double:
command='printf "\n"; route -n'
gnome-terminal --window-with-profile=Bash \
-e "bash -c '$command'"
Quoting can become really complex. When you need something more advanced that a simple couple of commands, it is advisable to write an independent shell script with all the readable, parametrized code you need, save it somewhere, say /home/user/bin/mycommand, and then invoke it simply as
gnome-terminal --window-with-profile=Bash -e /home/user/bin/mycommand
I have a script starting with:
#!/usr/bin/sudo bash
It does a non instant processing and is not meant to be interrupted, so I would like to add the -b option to sudo to run it in background after the password has been entered.
#!/usr/bin/sudo -b bash
However, the script does not accept the option. Am I doing something wrong ? Can one even pass an option that way ? And if not, why ?
Thank you in advance.
Let's ask shellcheck:
$ shellcheck yourscript
In yourscript line 1:
#!/usr/bin/sudo -b bash
^-- SC2096: On most OS, shebangs can only specify a single parameter.
A fair workaround is to have the script invoke itself with sudo based on a flag:
#!/bin/bash
if [[ $1 == "-n" ]]
then
echo "Processing as $(whoami)"
else
printf "Option -n not specified: invoking sudo -b %q -n:" "$0"
exec sudo -b "$0" -n
fi
This has the additional benefit of letting you run yourscript -n directly to not invoke sudo and not run in the background. This allows things like sudo yourscript -n && mail -s "Processing complete" you#example.com which would not be possible if the script unconditionally backgrounded itself.
Caveat: sudo "$0" is not a bullet proof way of reinvoking the current script.
This must either be really simple or really complex, but I couldn't find anything about it... I am trying to open a new bash instance, then run a few commands inside it, and give the control back to the user inside that same instance.
I tried:
$ bash -lic "some_command"
but this executes some_command inside the new instance, then closes it. I want it to stay open.
One more detail which might affect answers: if I can get this to work I will use it in my .bashrc as alias(es), so bonus points for an alias implementation!
bash --rcfile <(echo '. ~/.bashrc; some_command')
dispenses the creation of temporary files. Question on other sites:
https://serverfault.com/questions/368054/run-an-interactive-bash-subshell-with-initial-commands-without-returning-to-the
https://unix.stackexchange.com/questions/123103/how-to-keep-bash-running-after-command-execution
This is a late answer, but I had the exact same problem and Google sent me to this page, so for completeness here is how I got around the problem.
As far as I can tell, bash does not have an option to do what the original poster wanted to do. The -c option will always return after the commands have been executed.
Broken solution: The simplest and obvious attempt around this is:
bash -c 'XXXX ; bash'
This partly works (albeit with an extra sub-shell layer). However, the problem is that while a sub-shell will inherit the exported environment variables, aliases and functions are not inherited. So this might work for some things but isn't a general solution.
Better: The way around this is to dynamically create a startup file and call bash with this new initialization file, making sure that your new init file calls your regular ~/.bashrc if necessary.
# Create a temporary file
TMPFILE=$(mktemp)
# Add stuff to the temporary file
echo "source ~/.bashrc" > $TMPFILE
echo "<other commands>" >> $TMPFILE
echo "rm -f $TMPFILE" >> $TMPFILE
# Start the new bash shell
bash --rcfile $TMPFILE
The nice thing is that the temporary init file will delete itself as soon as it is used, reducing the risk that it is not cleaned up correctly.
Note: I'm not sure if /etc/bashrc is usually called as part of a normal non-login shell. If so you might want to source /etc/bashrc as well as your ~/.bashrc.
You can pass --rcfile to Bash to cause it to read a file of your choice. This file will be read instead of your .bashrc. (If that's a problem, source ~/.bashrc from the other script.)
Edit: So a function to start a new shell with the stuff from ~/.more.sh would look something like:
more() { bash --rcfile ~/.more.sh ; }
... and in .more.sh you would have the commands you want to execute when the shell starts. (I suppose it would be elegant to avoid a separate startup file -- you cannot use standard input because then the shell will not be interactive, but you could create a startup file from a here document in a temporary location, then read it.)
bash -c '<some command> ; exec /bin/bash'
will avoid additional shell sublayer
You can get the functionality you want by sourcing the script instead of running it. eg:
$cat script
cmd1
cmd2
$ . script
$ at this point cmd1 and cmd2 have been run inside this shell
Append to ~/.bashrc a section like this:
if [ "$subshell" = 'true' ]
then
# commands to execute only on a subshell
date
fi
alias sub='subshell=true bash'
Then you can start the subshell with sub.
The accepted answer is really helpful! Just to add that process substitution (i.e., <(COMMAND)) is not supported in some shells (e.g., dash).
In my case, I was trying to create a custom action (basically a one-line shell script) in Thunar file manager to start a shell and activate the selected Python virtual environment. My first attempt was:
urxvt -e bash --rcfile <(echo ". $HOME/.bashrc; . %f/bin/activate;")
where %f is the path to the virtual environment handled by Thunar.
I got an error (by running Thunar from command line):
/bin/sh: 1: Syntax error: "(" unexpected
Then I realized that my sh (essentially dash) does not support process substitution.
My solution was to invoke bash at the top level to interpret the process substitution, at the expense of an extra level of shell:
bash -c 'urxvt -e bash --rcfile <(echo "source $HOME/.bashrc; source %f/bin/activate;")'
Alternatively, I tried to use here-document for dash but with no success. Something like:
echo -e " <<EOF\n. $HOME/.bashrc; . %f/bin/activate;\nEOF\n" | xargs -0 urxvt -e bash --rcfile
P.S.: I do not have enough reputation to post comments, moderators please feel free to move it to comments or remove it if not helpful with this question.
With accordance with the answer by daveraja, here is a bash script which will solve the purpose.
Consider a situation if you are using C-shell and you want to execute a command
without leaving the C-shell context/window as follows,
Command to be executed: Search exact word 'Testing' in current directory recursively only in *.h, *.c files
grep -nrs --color -w --include="*.{h,c}" Testing ./
Solution 1: Enter into bash from C-shell and execute the command
bash
grep -nrs --color -w --include="*.{h,c}" Testing ./
exit
Solution 2: Write the intended command into a text file and execute it using bash
echo 'grep -nrs --color -w --include="*.{h,c}" Testing ./' > tmp_file.txt
bash tmp_file.txt
Solution 3: Run command on the same line using bash
bash -c 'grep -nrs --color -w --include="*.{h,c}" Testing ./'
Solution 4: Create a sciprt (one-time) and use it for all future commands
alias ebash './execute_command_on_bash.sh'
ebash grep -nrs --color -w --include="*.{h,c}" Testing ./
The script is as follows,
#!/bin/bash
# =========================================================================
# References:
# https://stackoverflow.com/a/13343457/5409274
# https://stackoverflow.com/a/26733366/5409274
# https://stackoverflow.com/a/2853811/5409274
# https://stackoverflow.com/a/2853811/5409274
# https://www.linuxquestions.org/questions/other-%2Anix-55/how-can-i-run-a-command-on-another-shell-without-changing-the-current-shell-794580/
# https://www.tldp.org/LDP/abs/html/internalvariables.html
# https://stackoverflow.com/a/4277753/5409274
# =========================================================================
# Enable following line to see the script commands
# getting printing along with their execution. This will help for debugging.
#set -o verbose
E_BADARGS=85
if [ ! -n "$1" ]
then
echo "Usage: `basename $0` grep -nrs --color -w --include=\"*.{h,c}\" Testing ."
echo "Usage: `basename $0` find . -name \"*.txt\""
exit $E_BADARGS
fi
# Create a temporary file
TMPFILE=$(mktemp)
# Add stuff to the temporary file
#echo "echo Hello World...." >> $TMPFILE
#initialize the variable that will contain the whole argument string
argList=""
#iterate on each argument
for arg in "$#"
do
#if an argument contains a white space, enclose it in double quotes and append to the list
#otherwise simply append the argument to the list
if echo $arg | grep -q " "; then
argList="$argList \"$arg\""
else
argList="$argList $arg"
fi
done
#remove a possible trailing space at the beginning of the list
argList=$(echo $argList | sed 's/^ *//')
# Echoing the command to be executed to tmp file
echo "$argList" >> $TMPFILE
# Note: This should be your last command
# Important last command which deletes the tmp file
last_command="rm -f $TMPFILE"
echo "$last_command" >> $TMPFILE
#echo "---------------------------------------------"
#echo "TMPFILE is $TMPFILE as follows"
#cat $TMPFILE
#echo "---------------------------------------------"
check_for_last_line=$(tail -n 1 $TMPFILE | grep -o "$last_command")
#echo $check_for_last_line
#if tail -n 1 $TMPFILE | grep -o "$last_command"
if [ "$check_for_last_line" == "$last_command" ]
then
#echo "Okay..."
bash $TMPFILE
exit 0
else
echo "Something is wrong"
echo "Last command in your tmp file should be removing itself"
echo "Aborting the process"
exit 1
fi
$ bash --init-file <(echo 'some_command')
$ bash --rcfile <(echo 'some_command')
In case you can't or don't want to use process substitution:
$ cat script
some_command
$ bash --init-file script
Another way:
$ bash -c 'some_command; exec bash'
$ sh -c 'some_command; exec sh'
sh-only way (dash, busybox):
$ ENV=script sh
Here is yet another (working) variant:
This opens a new gnome terminal, then in the new terminal it runs bash. The user's rc file is read first, then a command ls -la is sent for execution to the new shell before it turns interactive.
The last echo adds an extra newline that is needed to finish execution.
gnome-terminal -- bash -c 'bash --rcfile <( cat ~/.bashrc; echo ls -la ; echo)'
I also find it useful sometimes to decorate the terminal, e.g. with colorfor better orientation.
gnome-terminal --profile green -- bash -c 'bash --rcfile <( cat ~/.bashrc; echo ls -la ; echo)'