How to execute Zsh shell commands in Bash Script - bash

I want to execute Zsh function command in Bash script. Here is an example:
~/.zshrc
hello () {
echo "Hello!"
}
hello.sh
#!/bin/bash
hello
executing above bash script in zsh
(zsh) $ ./hello.sh
hello command not found
I also tried with heredocs:
#!/bin/bash
/bin/zsh - <<'EOF'
hello
EOF
executing above script with heredocs also says command not found error.
Any suggestions?
Thanks!

You can use it like that :
#!/bin/bash
/bin/zsh -i -c hello
-i : Force shell to be interactive
Then, if the shell is interactive, commands are read from /etc/zshrc and then $ZDOTDIR/.zshrc (this is usually your $HOME/.zshrc)
-c : Run a command in this shell

Related

bash shell script not executing in mac

I have a simple bash script test.sh
#!/bin/sh
# This is a comment
echo "Hi"
It does not execute anything when I try to run ./test.sh
$ ./test.sh
$
It comes with empty output. The mac terminal is executing echo commands but not shell script. I am not sure what I am missing. Please suggest.
to execute command file , type sh test.sh

Bash pass argument to --init-file script

I'm running a shell script using bash --init-file script.sh that runs some commands, then leaves an interactive session open. How can I pass arguments to this init file from the process that runs the initial bash command? bash --init-file 'script.sh arg' doesn't work.
Interestingly, if the script contains echo "$# $*", passing an argument as I did above causes it to print nothing, while not passing an argument prints '0'.
Create a file with the content:
#!/bin/bash
script.sh arg
Pass that file to bash: bash --init-file thatfile
I'd like the arg to come from the command that runs bash with the
Create a file from the command line and pass it:
arg="$1"
cat >thatfile <<EOF
$(declare -p arg)
script.sh \"\$arg\"
EOF
bash --init-file thatfile
You might be interested in researching what is a process substitution in bash.

Bash scripting shebang

I have this simple script:
#!/bin/dash
echo "Shell used:" $SHELL
I expected to get:
Shell used: /bin/dash
But instead of the output is:
Shell used: /bin/bash
I'm running the script as:
./my_script.sh

How to pass argument in bash pipe from terminal

i have a bash script show below in a file called test.sh
#!/usr/bin/env bash
echo $1
echo "execution done"
when i execute this script using
Case-1
./test.sh "started"
started
execution done
showing properly
Case-2
If i execute with
bash test.sh "started"
i'm getting the out put as
started
execution done
But i would like to execute this using a cat or wget command with arguments
For example like.
Q1
cat test.sh |bash
Or using a command
Q2
wget -qO - "url contain bash" |bash
So in Q1 and Q2 how do i pass argument
Something simlar to this shown in this github
https://github.com/creationix/nvm
Please refer installation script
$ bash <(curl -Ls url_contains_bash_script) arg1 arg2
Explanation:
$ echo -e 'echo "$1"\necho "done"' >test.sh
$ cat test.sh
echo "$1"
echo "done"
$ bash <(cat test.sh) "hello"
hello
done
$ bash <(echo -e 'echo "$1"\necho "done"') "hello"
hello
done
You don't need to pipe to bash; bash runs as standard in your terminal.
If I have a script and I have to use cat, this is what I'll do:
cat script.sh > file.sh; chmod 755 file.sh; ./file.sh arg1 arg2 arg3
script.sh is the source script. You can replace that call with anything you want.
This has security implications though; just running an arbitrary code in your shell - especially with wget where the code comes from a remote location.

How to specify zeroeth argument

I'm writing a bash script that starts the tcsh interpreter as a login shell and has it execute my_command. The tcsh man page says that there are two ways to start a login shell. The first is to use /bin/tcsh -l with no other arguments. Not an option, because I need the shell to execute my_command. The second is to specify a dash (-) as the zeroeth argument.
Now the bash exec command with the -l option does exactly this, and in fact the following works perfectly:
#!/bin/bash
exec -l /bin/tcsh -c my_command
Except... I can't use exec because I need the script to come back and do some other things afterwards! So how can I specify - as the zeroeth argument to /bin/tcsh without using exec?
You can enclose the exec command into a sub-shell of your script.
#!/bin/bash
(exec -l /bin/tcsh -c my_command)
# ... whatever else you need to do after the command is done
You can write a wrapper (w.sh) script that contains:
#!/bin/bash
exec -l /bin/tcsh -c my_command
and execute w.sh in your main script.

Resources