I made the switch to Ubuntu a couple of months ago and still do not have very much experience with unix and fish aside from the basic/often used commands. For a C class that I am taking I constantly need to SSH onto a remote linux machine run by my university called Zeus. The command to ssh onto it is a bit lengthy, and I would like to be able to make the process faster with a fish script.
I wrote a file called "zeus.fish" that essentially just calls my ssh command, among a few other things. Currently I can only run it by calling "fish zeus.fish" within the directory of the file. I would like to be able to run the script from within any directory, just like any other command. IE just typing "zeus" would attempt to log me into the remote machine. I'm assuming that I have to do something with PATH. How can I do this? Thanks!
You can make an executable and put it somewhere in $PATH. However, the simplest thing is to make a zeus function. A fish function is like a function in other languages: some named block of code.
Run this: function zeus; your_long_command_goes_here ; end
Run funcsave zeus to save it permanently
Now zeus will run that command.
What this does is put a file zeus.fish in ~/.config/fish/functions/. You can also do that manually of course.
I think this should work.
Add this to the first line of the script:
#!/bin/fish
That way it knows to execute your script with fish. Otherwise you would have to use ./scriptname or fish scriptname, to indicate you wanted fish to execute it.
Remove the .fish ending, if you want to call it just by "zeus".
Add the file to your path. In your .fishrc, write:
export PATH=XXX:$PATH
Okay, so I've never used fish. Apperently they don't use .fishrc, put it into your equivalent of .bashrc. Which is ~/.config/fish/config.fish as far as I can see. Actually the line you have to write is
set -x PATH $PATH XXX
With XXX being the path to your file, for example copy it into a folder named bin in your home directory. Then it would be
set -x PATH $PATH $HOME/bin
Last but not least, make the file executeable by writing:
chmod +x FILENAME
It seems like an alias would be a simpler solution for you however.
In your fish equivalent of .bashrc, you can do:
function zeus
ssh username#server
end
This seems to be the fish equivalent of an alias. If it is just 1 line that is long, you could do it like this. Having the line inside the function. Now you could just call "zeus" from anywhere aswell.
ridiculous_fish's answer is (obviously) entirely correct, but actually complicating it a bit in my opinion.
funced zeus; and funcsave zeus
will do the same thing in one go, launching an (empty) interactive function definition prompt in the first command, instantly saving it when editing finishes. If there is already a function of that name it will show up in the editor, so it's easy to continuously tweak your functions without having to dive into (or even consider the existence of) your fish config dir.
One of the very first functions I made when picking up the shell was "func", that makes exactly those two calls (since I only rarely edit a function without the intention of saving my changes)
For simple ssh stuff and other oneliners that don't take any input or where the input ($argv) is sure to just be appended at the end of the line,
alias zeus='ssh ...'; and funcsave zeus
will do the same. Any further editing will have to go through funced though.
Related
I am trying to make a command for the terminal. I have a bash script prepared (la.sh) and I want to just be able to type la to run it. How am I able to get the code so that I can just type la?
I have tried putting it in the /bin folder however had no luck.
What can I do to fix this?
I am using the latest version of Manjaro Gnome.
Thanks a lot!!!
BTW, the script was literally just ls.
It was just a practice script.
Lets consider that your script is stored under /some/path/la.sh. In my opinion, you have several solutions to accomplish your goal:
Option 1:
Add the script to your user's path so you can directly call it.
echo "export PATH=$PATH:/some/path/" >> ~/.bashrc
Then you will be able to use in your terminal:
$ la.sh
Using this option you can call la.sh with any parameters if needed. If the requirement is to call simply la you can also rename the script or create a softlink:
mv /some/path/la.sh /some/path/la
or
ln -s /some/path/la.sh /some/path/la
Option 2:
Create an alias for the script.
echo "alias la='/some/path/la.sh'" >> ~.bashrc
Then you will be able to use in your terminal:
$ la
However, using this option you will not be able to pass arguments to your script (executing something similar to la param1 param2) unless you define a more complex alias (an alias using a function in the .bashrc, but I think this is out of the scope of the question).
IMPORTANT NOTE: Remember to reload the environment in your terminal (source .bashrc) or to close and open again the terminal EVERY TIME you make modifications to the .bashrc file. Otherwise, you will not be able to see any changes.
The file la.sh must be placed in your path. Then you can create an alias for it.
alias la="la.sh"
If you want to have a command be available under two different names (la.sh and la in your case), I recommend against using an alias: An alias defined in your .bashrc is only available in an interactive bash; If you run, say, a non-bash interactive shell, or writing a bash script, you can't use it.
The IMO most general way is to create a link. Since you said that you have already placed la.sh into bin, you can create the link in the same directory, i.e.
ln /bin/la /bin/la.sh # creates a hard link
or
ln -s /bin/la /bin/la.sh # creates a symbolic link
In your case, either one is fine. If you want to find out more about the differences between hard and symbolic link, look for instance here.
It worked with a mixture of everybody's answers.
All I had to do was go into the directory that la.sh was in.
Rename it to just la as a text file.
Run chmod 777 la to turn it into executable to anybody.
Add it to my path by using the command export PATH=$PATH:~/Directory/It/Was/In/
Thank you to all who contributed.
So I am not experienced in dealing with a plethora of file types, and I haven't been able to find much info on exactly what .sh files are. Here's what I'm trying to do:
I'm trying to download map data sets which are arranged in tiles that can be downloaded individually: http://daymet.ornl.gov/gridded
In order to download a range of tiles at once, they say to download their script, which eventually leads to daymet-nc-retrieval.sh: https://github.com/daymet/scripts/blob/master/Bash/daymet-nc-retrieval.sh
So, what exactly am I supposed to do with this code? The website doesn't provide further instructions, assuming users know what to do with it. I'm guessing you're supposed to paste the code in to some other unmentioned application for a browser (using Chrome or Firefox in this case)? It almost looks like something that could be pasted in to Firefox/Greasemonkey, but not quite. Just by a quick Google on the file type I haven't been able to get heads or tails on it.
I'm sure there's a simple explanation on what to do with these files out there, but it seems to be buried in plenty of posts where people are already assuming you know what to do with these files. Anyone willing to just simply say what needs to be done from square one after getting to the page with the code to actually implementing it? Thanks.
What is a file with extension .sh?
It is a Bourne shell script. They are used in many variations of UNIX-like operating systems. They have no "language" and are interpreted by your shell (interpreter of terminal commands) or if the first line is in the form
#!/path/to/interpreter
they will use that particular interpreter. Your file has the first line:
#!/bin/bash
and that means that it uses Bourne Again Shell, so called bash. It is for all practical purposes a replacement for good old sh.
Depending upon the interpreter you will have different languages in which the file is written.
Keep in mind, that in UNIX world, it is not the extension of the file that determines what the file is (see "How to execute a shell script" below).
If you come from the world of DOS/Windows, you will be familiar with files that have .bat or .cmd extensions (batch files). They are not similar in content, but are akin in design.
How to execute a shell script
Unlike some unsafe operating systems, *nix does not rely exclusively on extensions to determine what to do with a file. Permissions are also used. This means that if you attempt to run the shell script after downloading it, it will be the same as trying to "run" any text file. The ".sh" extension is there only for your convenience to recognize that file.
You will need to make the file executable. Let's assume that you have downloaded your file as file.sh, you can then run in your terminal:
chmod +x file.sh
chmod is a command for changing file's permissions, +x sets execute permissions (in this case for everybody) and finally you have your file name.
You can also do it in your GUI. Most of the time you can right click on the file and select properties; in XUbuntu the permissions options look like this:
If you do not wish to change the permissions, you can also force the shell to run the command. In the terminal you can run:
bash file.sh
The shell should be the same as in the first line of your script.
How safe is it?
You may find it weird that you must perform another task manually in order to execute a file. But this is partially because of a strong need for security.
Basically when you download and run a bash script, it is the same thing as somebody telling you "run all these commands in sequence on your computer, I promise that the results will be good and safe". Ask yourself if you trust the party that has supplied this file, ask yourself if you are sure that you have downloaded the file from the same place as you thought, maybe even have a glance inside to see if something looks out of place (although that requires that you know something about *nix commands and bash programming).
Unfortunately apart from the warning above I cannot give a step-by-step description of what you should do to prevent evil things from happening with your computer; so just keep in mind that any time you get and run an executable file from someone you're actually saying, "Sure, you can use my computer to do something".
If you open your second link in a browser you'll see the source code:
#!/bin/bash
# Script to download individual .nc files from the ORNL
# Daymet server at: http://daymet.ornl.gov
[...]
# For ranges use {start..end}
# for individul vaules, use: 1 2 3 4
for year in {2002..2003}
do
for tile in {1159..1160}
do wget --limit-rate=3m http://daymet.ornl.gov/thredds/fileServer/allcf/${year}/${tile}_${year}/vp.nc -O ${tile}_${year}_vp.nc
# An example using curl instead of wget
#do curl --limit-rate 3M -o ${tile}_${year}_vp.nc http://daymet.ornl.gov/thredds/fileServer/allcf/${year}/${tile}_${year}/vp.nc
done
done
So it's a bash script. Got Linux?
In any case, the script is nothing but a series of HTTP retrievals. Both wget and curl are available for most operating systems and almost all language have HTTP libraries so it's fairly trivial to rewrite in any other technology. There're also some Windows ports of bash itself (git includes one). Last but not least, Windows 10 now has native support for Linux binaries.
sh files are unix (linux) shell executables files, they are the equivalent (but much more powerful) of bat files on windows.
So you need to run it from a linux console, just typing its name the same you do with bat files on windows.
Typically a .sh file is a shell script which you can execute in a terminal. Specifically, the script you mentioned is a bash script, which you can see if you open the file and look in the first line of the file, which is called the shebang or magic line.
I know this is an old question and I probably won't help, but many Linux distributions(e.g., ubuntu) have a "Live cd/usb" function, so if you really need to run this script, you could try booting your computer into Linux. Just burn a .iso to a flash drive (here's how http://goo.gl/U1wLYA), start your computer with the drive plugged in, and press the F key for boot menu. If you choose "...USB...", you will boot into the OS you just put on the drive.
How do I run .sh scripts?
Give execute permission to your script:
chmod +x /path/to/yourscript.sh
And to run your script:
/path/to/yourscript.sh
Since . refers to the current directory: if yourscript.sh is in the current directory, you can simplify this to:
./yourscript.sh
or with GUI
https://askubuntu.com/questions/38661/how-do-i-run-sh-scripts/38666#38666
https://www.cyberciti.biz/faq/run-execute-sh-shell-script/
open the location in terminal then type these commands
1. chmod +x filename.sh
2. ./filename.sh
that's it
I am trying to create a script that will run a program on each file in a list. I have been trying to do this using a .csh file (I have no clue if this is the best way), and I started with something as simple as hello world
echo "hello world"
The problem is that I cannot execute this script, or verify that it works correctly. (I was trying to do ./testscript.csh which is obviously wrong). I haven't been able to find anything that really explains how to run C Scripts, and I'm guessing there's a better way to do this too. What do I need to change to get this to work?
You need to mark it as executable; Unix doesn't execute things arbitrarily based on extension.
chmod +x testscript.csh
Also, I strongly recommend using sh or bash instead of csh, or you will soon learn about the idiosyncrasies of csh's looping and control flow constructs (some things only work inside them if done a particular way, in particular with the single-line versions things are very limited).
You can use ./testscript.csh. You will however need to make it executable first:
chmod u+x testscript.csh
Which means set testscript to have execute permissions for the user (who ever the file is owned by - which in this case should be yourself!)
Also to tell the OS that this is a csh script you will need put
#! /path/to/csh
on the first line (where /path/to/csh is the full path to csh on your system. You can find that out by issuing the command which csh).
That should give you the behvaiour you want.
EDIT As discussed in some of the comments, you may want to choose an alternative shell to C Shell (csh). It is not the friendliest one for scripting.
You have several options.
You can run the script from within your current shell. If you're running csh or tcsh, the syntax is source testscript.csh. If you're running sh, bash, ksh, etc., the syntax is . ./testscript.sh. Note that I've changed the file name suffix; source or . runs the commands in the named file in your current shell. If you have any shell-specific syntax, this won't work unless your interactive shell matches the one used by the script. If the script is very simple (just a sequence of simple commands), that might not matter.
You can make the script an executable program. (I'm going to repeat some of what others have already written.) Add a "shebang" as the first line. For a csh script, use #!/bin/csh -f. The -f avoids running commands in your own personal startup scripts (.cshrc et al), which saves time and makes it more likely that others will be able to use it. Or, for a sh script (recommended), used #!/bin/sh (no -f, it has a completely different meaning). In either case, run chmod +x the_script, then ./the_script.
There's a trick I often use when I want to perform some moderately complex action. Say I want to delete some, but not all, files in the current directory, but the criterion can't be expressed conveniently in a single command. I might run ls > tmp.sh, then edit tmp.h with my favorite editor (mine happens to be vim). Then I go through the list of files and delete all the ones that I want to leave alone. Once I've done that, I can replace each file name with a command to remove it; in vim, :%s/.*/rm -f &/. I add a #!/bin/sh at the top save it, chmod +x foo.sh, then ./foo.sh. (If some of the file names might have special characters, I can use :%s/.*/rm -f '&'/.)
i am novice to the Linux shell and had to recently start using it for work...i have now got used to the basic commands in bash to find my way around...however there are a lot of commands i find myself typing over and over again and its kind of a hassle to type them every time...so can anyone tell me how can i shorten the command syntax for ones i use frequently.
A very simple example, i use the ls -lh command often, though this is quite short but im just giving an example. Can I have something (a shell script may be) so that I can run it by typing just say lh.
I want to do it for more complex commands.
alias lh='ls -lh'
If you want to make this persistent across sessions, put it in your .bashrc file. Don't forget to run source .bashrc afterwards to make bash aware of the changes.
If you want to pass variables, an alias just isn't enough. You can make a function. As an example, consider the command lsall to list everything in a given directory (note this is just an example and thus very error prone):
function lsall
{
ls $1/*
}
$Ngets replaced with the Nth argument.
You would place the following alias in your .bashrc file:
alias lh='ls -lh'
Now lh is shorthand for ls -lh.
For more complicated tasks you could use a bash function. For example, on one of my machines I have a function which causes 'ls' to run after every successful 'cd':
cdls() {
builtin cd "$*" && ls
}
alias cd='cdls'
you can define aliases. For longer commands, use a function, put it into a library file and source it whenever you want to use your functions.
Just for the sake of completeness, since you want to learn bash: you could also write a function
lh() {
ls -lh "$#"
}
although I would never write that when a simple alias would do ;-)
;) Heh, I remember one problem when I was starting out on Linux, which is that I would ask questions like these, and people would diligently answer them, but no one would explain how to make such changes permanent, and so I found myself typing in a bunch of commands every time I opened a terminal.
So, even though others have accurately answered this question... if you want to make the change permanent, put the alias-line into your ~/.profile or ~/.bashrc file (~ = your home directory). It depends a bit on your distribution on which is run when, but I always try adding my aliases to ~/.profile first and if that doesn't work, then ~/.bashrc. One of them should work for sure.
This question already has answers here:
Multiple commands in an alias for bash
(10 answers)
Closed 4 years ago.
I know how to configure aliases in bash, but is there a way to configure an alias for a sequence of commands?
I.e say I want one command to change to a particular directory, then run another command.
In addition, is there a way to setup a command that runs "sudo mycommand", then enters the password? In the MS-DOS days I'd be looking for a .bat file but I'm unsure of the linux (or in this case Mac OSX) equivalent.
For chaining a sequence of commands, try this:
alias x='command1;command2;command3;'
Or you can do this:
alias x='command1 && command2 && command3'
The && makes it only execute subsequent commands if the previous returns successful.
Also for entering passwords interactively, or interfacing with other programs like that, check out expect. (http://expect.nist.gov/)
You mention BAT files so perhaps what you want is to write a shell script. If so then just enter the commands you want line-by-line into a file like so:
command1
command2
and ask bash to execute the file:
bash myscript.sh
If you want to be able to invoke the script directly without typing "bash" then add the following line as the first line of the file:
#! /bin/bash
command1
command2
Then mark the file as executable:
chmod 755 myscript.sh
Now you can run it just like any other executable:
./myscript.sh
Note that unix doesn't really care about file extensions. You can simply name the file "myscript" without the ".sh" extension if you like. It's that special first line that is important. For example, if you want to write your script in the Perl programming language instead of bash the first line would be:
#! /usr/bin/perl
That first line tells your shell what interpreter to invoke to execute your script.
Also, if you now copy your script into one of the directories listed in the $PATH environment variable then you can call it from anywhere by simply typing its file name:
myscript.sh
Even tab-completion works. Which is why I usually include a ~/bin directory in my $PATH so that I can easily install personal scripts. And best of all, once you have a bunch of personal scripts that you are used to having you can easily port them to any new unix machine by copying your personal ~/bin directory.
it's probably easier to define functions for these types of things than aliases, keeps things more readable if you want to do more than a command or two:
In your .bashrc
perform_my_command() {
pushd /some_dir
my_command "$#"
popd
}
Then on the command line you can simply do:
perform_my_command my_parameter my_other_parameter "my quoted parameter"
You could do anything you like in a function, call other functions, etc.
You may want to have a look at the Advanced Bash Scripting Guide for in depth knowledge.
For the alias you can use this:
alias sequence='command1 -args; command2 -args;'
or if the second command must be executed only if the first one succeeds use:
alias sequence='command1 -args && command2 -args'
Your best bet is probably a shell function instead of an alias if the logic becomes more complex or if you need to add parameters (though bash supports aliases parameters).
This function can be defined in your .profile or .bashrc. The subshell is to avoid changing your working directory.
function myfunc {
( cd /tmp; command )
}
then from your command prompt
$ myfunc
For your second question you can just add your command to /etc/sudoers (if you are completely sure of what you are doing)
myuser ALL = NOPASSWD: \
/bin/mycommand
Apropos multiple commands in a single alias, you can use one of the logical operators to combine them. Here's one to switch to a directory and do an ls on it
alias x="cd /tmp && ls -al"
Another option is to use a shell function. These are sh/zsh/bash commands. I don't know enough of other shells to be sure if they work.
As for the sudo thing, if you want that (although I don't think it's a good idea), the right way to go is to alter the /etc/sudoers file to get what you want.
You can embed the function declaration followed by the function in the alias itself, like so:
alias my_alias='f() { do_stuff_with "$#" (arguments)" ...; }; f'
The benefit of this approach over just declaring the function by itself is that you can have a peace of mind that your function is not going to be overriden by some other script you're sourcing (or using .), which might use its own helper under the same name.
E.g., Suppose you have a script init-my-workspace.sh that you're calling like . init-my-workspace.sh or source init-my-workspace.sh whose purpose is to set or export a bunch of environment variables (e.g., JAVA_HOME, PYTHON_PATH etc.). If you happen to have a function my_alias inside there, as well, then you're out of luck as the latest function declaration withing the same shell instance wins.
Conversely, aliases have separate namespace and even in case of name clash, they are looked up first. Therefore, for customization relevant to interactive usage, you should only ever use aliases.
Finally, note that the practice of putting all the aliases in the same place (e.g., ~/.bash_aliases) enables you to easily spot any name clashes.
you can also write a shell function; example for " cd " and "ls " combo here