I trying to create a .sh file that execute things like "pwd" or "ls" command.
My problem its when i execute the .sh file.
Its seems not recognize the tasks
I tried to use echo
Example : echo 'lsApps' or echo "lsApps"
but it prints the name of the task instead execute the comand
for example i want to execute a .ssh file that makes a pwd
VAR_1=pwd
echo $VAR_1
but it prints me pwd instead the current path ...
Any idea?
echo is used to print on the screen (man page reference). If you do echo 'IsApps' it will take it as a string and print it. If you want to execute a command you can just do it by doing IsApps (acutes not quotes, acute is usually below the escape key). This will execute the command and show the output on the screen. If you want to store the output of the command in a variable, you can do
<variable_name>=`IsApps`
This will store the output in the variable. Note that there is no space between variable name and the command. Also, those are not quotes but instead acutes. To print the variable on screen you can use echo by doing echo $<variable_name>
If you don't want to see the output at all. You can do
IsApps > /dev/null
this will execute the command but you will not see any stdout on your screen.
As far as ssh is concerned, do ssh-keygen and then ssh-copy-id user#remote_ip to set ssh keys so that you don't have to enter your password with ssh. Once you have done that, you can use ssh user#remote_ip in your shell script.
Related
I'm struggling with passing a shell command. Specifically, I have written a shell file that the user will run. In it, another shell file is written based on the user inputs. This file will then be passed to a command that submits the job.
Now in this internal shell file I have a variable containing a function. However, when I run the user shell script I can't get this function to pass in a way that the internal shell file can use it.
I can't share my work but I'll try to make an example
#User shell script
cat >test.txt <<EOF
#a bunch of lines that are not relevant
var=`grep examples input.txt`
/bin/localfoo -${var}
EOF
# pass test.txt to localfoo2
/bin/localfoo2 /test.txt
When I run the 'User Shell Script' it prints that grep can't find the file, but I don't want grep to be evaluated. I need it to be written, as is, so that when the line '/bin/localfoo2 /test.txt' is read, grep is evaluated.
I've tried a number of things. I've tried double back ticks, i've tried using 'echo $(eval $var)'. But none of the methods I've found through googling have managed to pass this var in a way that will accomplish what I want.
Your help is much appreciated.
You can try with single quote (').
You have to put the single quote in before the grep command and end of the grep command like below.
#User shell script
cat >test.txt <<EOF
#a bunch of lines that are not relevant
var='`grep examples input.txt`'
/bin/localfoo -${var}
EOF
# pass test.txt to localfoo2
/bin/localfoo2 /test.txt
I did not understand where you have to execute that grep command.
If you want to execute the grep command inside the localfoo script, I hope this method will help.
I'm trying to grep the user command into a variable.
If the command begins with specific words I'm redirecting the command into another shell (not BASH), if not it will run regularly on bash.
When I'm using "read" I lose the BASH prompt then I'm unable to auto-complete, backspace etc.
My goal is:
if I type for example ls -la the command will not run and will be assigned into variable:
user#machine:~$ ls -la
user_command = 'ls -la'
if the command is not other shell command (not BASH)
eval $user_command
Is there any way to achieve this?
I guess you want to : invoke some specific commands through another shell instead of bash
You could define a function for each of those commands
exemple:
ls () { # function that, instead of bash, launch 'ls' through ksh
ksh -c "ls $*"
}
that way, with each function's name matching the command you want to run with another shell (edit the inside of the function accordingly if it needs to be run with another shell than ksh)
Place those function in specific user's "~/.bashrc" files.
You could write your implementation of ls and place it in ~/bin/ls.
Give full permissions to this file
I need to execute multiple commands on remote machine, and use ssh to do so,
ssh root#remote_server 'cd /root/dir; ./run.sh'
In the script, I want to pass a local variable $argument when executing run.sh, like
ssh root#remote_server 'cd /root/dir; ./run.sh $argument'
It does not work, since in single quote $argument is not interpreted the expected way.
Edit: I know double quote may be used, but is there any side effects on that?
You can safely use double quotes here.
ssh root#remote_server "cd /root/dir; ./run.sh $argument"
This will expand the $argument variable. There is nothing else present that poses any risk.
If you have a case where you do need to expand some variables, but not others, you can escape them with backslashes.
$ argument='-V'
$ echo "the variable \$argument is $argument"
would display
the variable $argument is -V
You can always test with double quotes to discover any hidden problems that might catch you by surprise. You can always safely test with echo.
Additionally, another way to run multiple commands is to redirect stdin to ssh. This is especially useful in scripts, or when you have more than 2 or 3 commands (esp. any control statements or loops)
$ ssh user#remoteserver << EOF
> # commands go here
> pwd
> # as many as you want
> # finish with EOF
> EOF
output, if any, of commands will display
$ # returned to your current shell prompt
If you do this on the command line, you'll get a stdin prompt to write your commands. On the command line, the SSH connection won't even be attempted until you indicate completion with EOF. So you won't see results as you go, but you can Ctrl-C to get out and start over. Whether on the command line or in a script, you wrap up the sequence of commands with EOF. You'll be returned to your normal shell at that point.
You could run xargs on the remote side:
$ echo "$argument" | ssh root#remote_server 'cd /root/dir; xargs -0 ./run.sh'
This avoids any quoting issues entirely--unless your argument has null characters in it, I suppose.
I want to run the same set of Unix commands on multiple machines. I am aware of ssh and something like the below. I want to write a shell script to do this. I have access to bash and ksh and I'm on Linux Red Hat 5.
ssh root#ip "echo \$HOME"
However, I have 2 questions:
I keep getting prompted for a password. How can I have it not prompt me and enter the password automatically?
How can I execute multiple commands?
You should use key based authentification, possibly coupled with ssh-agent to remember key passphrase.
You can invoke sh -c as the command, and pass it a string containing the list of command to execute. ssh invoke a shell on the remote machine, so you can pass a list of command as a string.
For example:
$ ssh user#ip "echo 'Hello world'; whoami; cd / ; ls"
Use ssh-agent to set up authentication for all commands. Or put your multiple commands into a single shell script.
Send a list of commands to the remote shell. Possible solutions:
use ", escape line breaks to format code and end each substatement with ;.
Disadvantage: " should not be used inside the command list.
ssh user#ip "\
echo 'Hallo sir, how are you doing?';\
whoami;\
cd /;\
ls\
"
use ' and format code with regular line breaks.
Disadvantage: ' should not be used inside the command list.
ssh user#ip '
echo "Hallo sir, how are you doing?"
whoami
cd /
ls
'
Note: using " or ' inside the respective statements will not necessarily result in an error. Though you may get unsuspected results.
I'm making a shell script and I want to know if it's possible to write directly to the command line when the script is executed ?
Example :
user#localhost:/home/user$./script.sh
... output
... another output
... another output
... last output
user#localhost:/home/user$I want to write here on the command line
I don't want to "echo" some text, I want to write directly at the prompt.
Thanks!
No, you can't do that. If you want user to invoke your provided command after your script is finished - why not just prompt user for confirmation?
If you just want the text to show up there, but not be able to do anything with it, you can do this.
File test.sh:
echo "Output"
./test2.sh &
File test2.sh:
echo "Output2"
Notice how the first script calls the second script with the & at the end.
In this case, "Output2" will be written to the prompt, but it can't be deleted and will have no effect on the next command at all. But if this is something you're doing to grab the user's attention, it would work.
In ksh:
print -s $(script)
will print to the command history. Wrap this in a function and you'll have something close to what you are asking for.
If you are using X environment install xclip and xdotool, then:
#!/bin/bash
your scripts....
echo -n your command to write 2>&1|xclip
xdotool click 2