Bash import or export variables - bash

I am adding commands into my bash profile and am trying to make my code simpler and want to delete the extraneous duplicated code. I have export statements and I have the commands running correctly but I am trying to simplify my code. I am using the same exact code for my commands and want to make it into one file. I am running the commands on a Mac terminal. I have installed npm, atom, atom shell commands and am on Mac OS version 10.14.5.
I tried changing the code structure around but I cannot figure out how to simplify and reuse the commands and make them into a function. The commands are duplicates of each other except that they are pointing to different file paths. I do not want to keep on reusing the same code and I am hoping to make it simpler but not sure how.
export snippet_project="/Users/kevinpleong/Desktop/my-programming-projects/snippet-creator-electronjs"
export programmingprojects="/Users/kevinpleong/Desktop/my-programming-projects"
export personal_website="/Users/kevinpleong/Desktop/my-programming-projects/personal-webiste"
edit-snippet-creator() {
cd /Users/kevinpleong/Desktop/my-programming-projects/snippet-creator-electronjs
atom .
}
edit-personal-website(){
cd /Users/kevinpleong/Desktop/my-programming-projects/personal-website/
atom .
}
edit-programming-projects(){
cd /Users/kevinpleong/Desktop/my-programming-projects/
atom .
}
I am hoping that it outputs the same thing as the bottom 3 blocks of code but I can simplify the code.

The code can be simplified to this:
projects_directory="${HOME}/Desktop/my-programming-projects"
edit-snippet-creator() {
atom "${projects_directory}/snippet-creator-electronjs"
}
edit-personal-website(){
atom "${projects_directory}/personal-website"
}
edit-programming-projects(){
atom "$projects_directory"
}
The exports are redundant
The variables are redundant since they would only each be used once. Only the projects directory is reused.
Trailing slashes are unnecessary.
Use More Quotes™.
That said, as you get used to the shell I expect you'll want to move away from patterns like this, because they are a premature abstraction and they hinder you from learning all the powerful built-in features of the shell, such as Tab completion. For example, if you've already edited a project you can press Ctrl-r to search the command history for the name of that project. Also, I expect atom, like every sane shell command, can take a directory different from the current one as the target, so you can simply type atom ~/Desktop/my, press Tab to complete atom ~/Desktop/my-programming-projects/, and press Tab again to see which projects are available.

Related

How to set custom variables for directories in shell?

so I'm new to the world of Linux. Due to my new internship however, I have to work a lot with it and thus also get a hang of using the terminal appropriately.
Is there a way to set path-variables for faster navigation through directories? Similar to using '~' as an abbreviation for '/home/usr/'.
So far, I have tried to use:
```
name#torch:~$ export var=/home/usr/where/i/want/to/go
name#torch:~$ cd $var
name#torch:~/where/i/want/to/go$ ...
```
This option works only temporarily in a single shell but is not adapted when closing down the terminal or starting another one next to it. Is there a way to define more general path-variables?
Best wishes,
Hauke

How do I give my shell script a simple word to make it run. For example "mkdir"

so I have a bash script right now which automates the git process for me. I have made the shell script accessible from everywhere. I want to give the script a command like "ctdir" instead of typing in "intilize_directory.sh" every time. Is there a way to make this possible?
There are (at least) three ways to do this:
First, if it's on your path, you can simply rename it to ctdir.
Second, you can create an alias for it in your startup scripts (like $HOME/.bashrc):
alias ctdir='initialize_directory.sh'
Third, you can create a function to do the work (again, defining it in your startup scripts):
ctdir() {
initialize_directory.sh
}
Just remember to make sure you load up your modified startup scripts after making the changes. New shells should pick the changes up but you may need to re-source it manually from an existing shell (or just exit and restart).
Agreed with #paxdiablo, the best way is to create an alias.
Following steps will work in Linux:
Naming the alias.
Type the following at the command line:
alias ctdir='initialize_directory.sh'
Edit bashsrc file.
This file is usually present at your home directory.
Add at the alias mentioned in step 1 at the end of the bashsrc file to make them permanent and reusable in every session.
vi ~/.bashsrc

Tab completion ignoring some files in Bash/Debian

I am using tab completion in a standard Debian install with Bash and I have some files being ignored. For example, if I have the files:
index.php
index.php.a
If I type vim i then tab it immediately selects "index.php " (see space after file name). Normally, it would just complete up to "index.php" and give me the option to type something else after.
Why is it behaving differently in this situation?
Update
Some commands such as "cp" seem to handle the tab completion just fine, so maybe it is vim looking for specific file extensions?
The bash-completion package uses the function _filedir_xspec to complete vim. That function in general completes filenames, but excludes certain patterns depending on which command it is completing.
For vim, the exclusion pattern starts like this:
_install_xspec '*.#([ao]|so|so.!(conf|*/*) ...
I.e., among other things, files ending in .a should be ignored. The thinking behind that is probably that these are often created as backup copies and you probably don't want to edit them.
If you want to override this behaviour, you can add your own completions into ~/.bash_completion; for example, to get vim to complete on all filenames, use this:
complete -f vim
which will make vim tab completion default to the built-in file completion bevahiour.

Add Path to OSX to El Capitan

I am trying to learn UNIX.
I am using a book called “Wicked Cool Shell Scripts”.
I am told that .bash_profile contains my login for bash and that I can add paths to it so that commands I enter in Terminal will find the scripts I am writing.
The contents of my current bash_profile is:
export PATH=~/bin:$PATH
When I type echo $PATH I get:
/usr/local/opt/php#7.0/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/Library/Frameworks/Python.framework/Versions/3.3/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin
I would like to add a path so that - as the book suggests - I can write scripts and refer to them directly from the command line, instead of having to constantly navigate to that directory to run them.
I have a file with a shebang. It runs fine when I type its name and am in the same directory. I have moved that file to the folder scripts, which is located under crg/Users/ (ie: Users/crg/scripts)
According to this book, I can now alter my $PATH to include that directory, so that when I type that filename, the program will run.
I cannot do this successfully.
I don’t know why.
After every edit, I quit terminal and reopen it, to ensure it is using the newly edited bash_profile.
As per the books instructions on page 5, I have tried entering this in my bash_profile:
export PATH=”/Users/crg/scripts/:$PATH”
I save my bash_profile, quit Terminal, reopen it and type echo $Path
This is the result:
”/Users/crg/scripts/:??
This is not right. In fact, it's wildly wrong. And it does not allow me to run scripts from the folder indicated. It also seems to completely overwrite whatever was in the bash_profile before this, so I cannot - after doing this 'simple edit' suggested by a 'professional' - run a php -version command from the Terminal.
I am at a complete loss as to why this is happening.
Why is there a quotation mark at the beginning of this line (but not at the end)?
What's with the colon and the 2 question marks at the end of this line?
How do I add/append a path to my bash_profile?
More questions:
When I try and solve this on my own using “the Internet”, I discover many interesting versions of this ‘simple’ process: Here’s one suggested by a ‘professional’:
export PATH="${PATH}:/path/to/program/inside/package"
This is very different from what the book says...
Here’s another version of ‘how to do it’ by ‘a professional’:
export PATH=$PATH:/usr/local/sbin/modemZapp
Notice that this one doesn’t even have quotes. In both, the PATH variable comes before the actual path.
Why are there so many 'versions' of how to perform this simple task?
Can someone please tell me how to add a path to my .bash_profile?
UPDATE: I have followed the advice here, (add it to etc/paths) but this does not work either.
I get the exact same thing when I type echo $PATH in a new Terminal:
/usr/local/opt/php#7.0/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/Library/Frameworks/Python.framework/Versions/3.3/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr:/usr/local/share/npm/bin:/Users/fhb/scripts:/opt/X11/bin
I can't help but note a comment on that last page: "I have been through at least a dozen different methods for adding directories to $PATH. Why are there so many and why do so few of them work?"
To answer your first question if you look closely your quotes are ” instead of ". I'm guessing you edited either your bash_profile or this post in a rich text editor instead of a plain text one. I would recommend notepad for Windows or nano for *nix if you are writing code. To fix this issue, replace the ” with ".
To answer your second question, bash is quite forgiving and will allow you to set a string variable in multiple different ways, even without quotes. However you can run into issues when a string contains whitespace, for example: /Users/lilHenry/my scripts.
The "${PATH}" syntax is just another way to declare a string. It has the benefit that it allows you to interpolate variables into a string like so:
prefix="foo"
echo "${prefix}bar"
This will output foobar, whereas echo "$prefixbar" will not output anything as the variable prefixbar has not been set. I would suggest sticking with the export PATH="/Users/me/bin:$PATH" syntax.

How can I make shell autocomplete the beginning of a filepath?

I have a project with a deeply nested folder structure. Most of the time I know the name of the file I want to work with, but the folder path is too long/complicated to type when I want to edit it, like:
vim folder/is/deep/down/there/myfile.js
Is there a way to make the shell auto populate the path for me if the filename is unique, with something like:
vim *myfile.js
press TAB -->
vim folder/is/deep/down/there/myfile.js
I mostly use bash, but I'm fine with zsh if it can solve the problem.
I think this is what you're looking for, vim will open all instances of myfile.js in the directory. Fish shell will allow me to tab through the different matching files but I'm not sure it that works with bash.
vim **/myfile.js
What could be a good idea would be to use locate utility in a bash script.
Calling your bash script passing filename as argument would be a smart move, and then using the previously named utility to find it.
Having done that you could simply find if there was 1 or more matches, and if there's just a match you can just use vim [match].
And obviously, the script could be called like ./openinvim.sh myfile.js

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