I want to check if tmux alias exists, when I run command in terminal:
$ type -t tmux
the result is
$ alias
But when I put "type -t tmux" in a shell script and run, the result is
$ ./test.sh
$ file
Why the result is different ?
My test.sh is:
#!/usr/bin/env bash
set -e
type -t tmux
Any aliases defined in .bash_profile should be read and respected by tmux, but does not read anything in .bashrc.
Invoking test.sh is a sub-process, and does not use environment from current process unless you source it
source test.sh but that also allows that script to modify current environment.
Related
I am currently using ssh to access a linux computer. I use the command:
ssh -t user#hostaddress 'cd ~/Desktop && bash'
When I get there, I see that neither ~/.bash_profile nor ~/.profile are sourced. What are the rules surrounding when these are sourced in? The reason I call bash is because I am able to get terminal colors when I do bash (blue folders, etc) that I otherwise cannot get just by using ssh user#hostaddress.
You're not running bash as a login shell -- using bash -l should source .bash_profile. Otherwise you can use .bashrc.
This question already has answers here:
How to use aliases defined in .bashrc in other scripts?
(6 answers)
Closed 2 years ago.
My alias defined in a sample shell script is not working. And I am new to Linux Shell Scripting.
Below is the sample shell file
#!/bin/sh
echo "Setting Sample aliases ..."
alias xyz="cd /home/usr/src/xyz"
echo "Setting done ..."
On executing this script, I can see the echo messages. But if I execute the alias command, I see the below error
xyz: command not found
am I missing something ?
source your script, don't execute it like ./foo.sh or sh foo.sh
If you execute your script like that, it is running in sub-shell, not your current.
source foo.sh
would work for you.
You need to set a specific option to do so, expand_aliases:
shopt -s expand_aliases
Example:
# With option
$ cat a
#!/bin/bash
shopt -s expand_aliases
alias a="echo b"
type a
a
$ ./a
# a is aliased to 'echo b'
b
# Without option
$ cat a
#!/bin/bash
alias a="echo b"
type a
a
$ ./a
./a: line 3: type: a: not found
./a: line 4: a: command not found
reference: https://unix.stackexchange.com/a/1498/27031 and https://askubuntu.com/a/98786/127746
sourcing the script source script.sh
./script.sh will be executed in a sub-shell and the changes made apply only the to sub-shell. Once the command terminates, the sub-shell goes and so do the changes.
OR
HACK: Simply run following command on shell and then execute the script.
alias xyz="cd /home/usr/src/xyz"
./script.sh
To unalias use following on shell prompt
unalias xyz
If you execute it in a script, the alias will be over by the time the script finishes executing.
In case you want it to be permanent:
Your alias is well defined, but you have to store it in ~/.bashrc, not in a shell script.
Add it to that file and then source it with . .bashrc - it will load the file so that alias will be possible to use.
In case you want it to be used just in current session:
Just write it in your console prompt.
$ aa
The program 'aa' is currently not installed. ...
$
$ alias aa="echo hello"
$
$ aa
hello
$
Also: From Kent answer we can see that you can also source it by source your_file. In that case you do not need to use a shell script, just a normal file will make it.
You may use the below command.
shopt -s expand_aliases
source ~/.bashrc
eval $command
Your alias has to be in your .profile file not in your script if you are calling it on the prompt.
If you put an alias in your script then you have to call it within your script.
Source the file is the correct answer when trying to run a script that inside has an alias.
source yourscript.sh
Put your alias in a file call ~/.bash_aliases and then, on many distributions, it will get loaded automatically, no need to manually run the source command to load it.
I am writing a a bash script (echoo.sh) with the intention of echoing the command before it is executed. I source this script (echoo.sh) inside .bashrc. But it does not execute for commands run in script file(tmp.sh) with the bash shebang. Below is the code I have so far
echoo.sh
#!/usr/bin/env bash
shopt -s extdebug; get_hacked () {
[ -n "$COMP_LINE" ] && return # not needed for completion
[ "$BASH_COMMAND" = "$PROMPT_COMMAND" ] && return # not needed for prompt
local this_command=$BASH_COMMAND;
echo $this_command;
};
trap 'get_hacked' DEBUG
When I open a shell and run any command - It works. But for stuff in a script file it doesn't work.
SOME FURTHER TRIES:
I tried sourcing the .bashrc file within the script file (tmp.sh) - didn't work.
I sourced echoo.sh inside tmp.sh and it worked.
SO, I am trying to understand
Why doesn't it work if I just source my script in .bashrc for stuff that runs in scripts?
Why doesn't further try #1 work when #2 does.
AND finally what can I do such that I don't have to source echoo.sh in all script files for this to work. Can source my script in one place and change some setting such that it works in all scenarios.
I source this script (echoo.sh) inside .bashrc. But it does not execute for commands run in script file(tmp.sh) with the bash shebang
Yes it won't because you are invoking the shell non-interactively!
The shell can be spawned either interactively or non-interactively. When bash is invoked as an interactive login shell it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable.
When an interactive shell that is not a login shell is started, bash reads and executes commands from ~/.bashrc, if that file exists.
When you run a shell script with an interpreter set, it opens a new sub-shell that is non-interactive and does not have the option -i set in the shell options.
Looking into ~/.bashrc closely you will find a line saying
# If not running interactively, don't do anything
[[ "$-" != *i* ]] && return
which means in the script you are calling, e.g. consider the case below which am spawning a non-interactive shell explicitly using the -c option and -x is just to enable debug mode
bash -cx 'source ~/.bashrc'
+ source /home/foobaruser/.bashrc
++ [[ hxBc != *i* ]]
++ return
which means the rest of the the ~/.bashrc was not executed because of this guard. But there is one such option to use here to read a start-up file for such non-interactive cases, as defined by BASH_ENV environment variable. The behavior is as if this line is executed
if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
You can define a file and pass its value to the local environment variable
echo 'var=10' > non_interactive_startup_file
BASH_ENV=non_interactive_startup_file bash -x script.sh
Or altogether run your shell script as if an interactive non login shell is spawned. Run the script with an -i flag. Re-using the above example, with the -i flag passed now the ~/.bashrc file will be sourced.
bash -icx 'source ~/.bashrc'
You could also set this option when setting your interpreter she-bang in bash to #!/bin/bash -i
So to answer your questions from the above inferences,
Why doesn't it work if I just source my script in .bashrc for stuff that runs in scripts?
It won't because ~/.bashrc cannot be sourced from a shell that is launched non-interactively. By-pass it by passing -i to the script i.e. bash -i <script>
Why doesn't further try #1 work when #2 does.
Because you are depending on reading up the ~/.bashrc at all here. When you did source the echoo.sh inside tmp.sh, all its shell configurations are reflected in the shell launched by tmp.sh
I'd like to check the value of $HISTFILE (or any similar BASH-Variable) by a bash script. On the command console 'echo $HISTFILE' is the way I normally go, but from inside a bash script, which only includes:
#!/bin/bash
echo $HISTFILE
gives an empty line instead of showing $HOME/$USER/.bash_history (or similar return values). My questions are:
What is the reason for doing so (since I never had such trouble using bash scripts) and
how can I check the value of BASH-Variables like $HISTFILE from inside a bash script?
Many thanks in advance. Cheers, M.
HISTFILE is only set in interactive shells; scripts run in non-interactive shells. Compare
$ bash -c 'echo $HISTFILE' # non-interactive, no output
$ bash -ic 'echo $HISTFILE' # interactive, produces output
/home/me/.bash_history
However, forcing the script to run in an interactive shell will also cause your .bashrc file to be sourced, which may or may not be desirable.
I have an application named puppet installed on my Linux box. It is installed at location /usr/test/bin/puppet
This is how .bash_profile looks
export PATH=/usr/test/bin
if I run command puppet apply from console, it works fine but when I call puppet command from inside bash script, it says command not found
#!/bin/bash
puppet apply x.pp
Any ideas on what is wrong ?
.bash_profile is loaded only if bash is invoked as login shell (bash -l or from a real tty), at least in Debian based distributions bash in a virtual tty (for example when using xterm, gnome-terminal, etc...) is invoked as interactive shell.
Interactive shells loads the configuration from ~/.bashrc.
bash manpage:
~/.bash_profile
The personal initialization file, executed for login shells
~/.bashrc
The individual per-interactive-shell startup file
Shellscripts don't load any of these.
You can check which files are opened by any program with strace:
strace ./s.sh 2>&1 | grep -e stat -e open
Possible solutions:
You can export the variable at the beginning of every script:
#!/bin/bash
export PATH=$PATH:...
Or you can have another file with the desired variables and source it from any script that need those:
/etc/special_vars.sh:
export PATH=$PATH:...
script:
#!/bin/bash
. /etc/special_vars.sh
puppet ...
Configure the PATH in in ~/.bashrc, ~/.bash_profile and ~/.profile for the user running the script (sub-processes will inherit the environment variables) to have some warranty that the user can run the script from different environments and shells (some bourne compatible shells others than bash do load ~/.profile)
Maybe the export of PATH is wrong?
export PATH=$PATH:/usr/test/bin/puppet
You could try using an alias, like so
in your .bash_profile:
alias puppet='bash puppet.fileextension'
you can also do
alias puppet='bash path/to/puppet.fileextension'
which will let you run the script from anywhere in Terminal.
EDIT:
OP has stated in the comments that there will be two different systems running, and he asked how to check the file path to the bash file.
If you do
#!/bin/bash
runPuppet(){
if [ -e path/to/system1/puppet.fileextension]
then
bash path/to/system1/puppet.fileextension $1 $2
elif [ -e path/to/system2/puppet.fileextension]
then
bash path/to/system2/puppet.fileextension $1 $2
fi
}
runPuppet apply x.pp
and change the runPuppet input to whatever you'd like.
To clarify/explain:
-e is to check if the file exists
$1 & $2 are the first two input parameters, respectively.