Bin bash what does it mean

When you run a bash script, it will always run in a new subshell. This means that any unique configurations you have in your current setup will not be used within the script execution. It also means that you can customize the environment that the script is running in without worrying about how your terminal will be affected. One way to change this environment is to use the set command. So if you want to have your script exit at a certain point, you have to define it.

For example, you may have the following script:. Double QuotesIf you want to echo the contents of a variable, then use double quotes. The third option for using a variable is backticks. Use this when you want the contents of the variable to be run as a shell command:. Properly Set PermissionsOne of the pitfalls that I remember running into time and time again when I started making bash scripts was remembering that permissions had to be set right.

Luckily this is easily fixed. However, do be aware that changing permissions can impose security risks. Read more about Linux file permissions before you start changing permissions blindly.

Ensure ReadabilityOne of the biggest pitfalls that newcomers run into is forgetting about readability. You can write commands using a hash mark, after which you can write your comment, like so: Below line will echo "Hello World! You can write everything you write in a bash script directly in the terminal. There is one significant difference between executing a script and typing the commands in your terminal.

Read the manual; it does cover that detail. KarthikT it doesn't run the default shell, it runs bash in Bourne Shell mode. Show 5 more comments. In bash script, what does! Hope this will eliminate your confusions Joshua D.

Boyd Joshua D. Boyd 4, 2 2 gold badges 28 28 silver badges 44 44 bronze badges. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete?

Podcast Do polyglots have an edge when it comes to mastering programming Featured on Meta. Now live: A fully responsive profile. Linked Related Viewed 3k times. Quoting ilkkachu in the comments below this question , directly addressing this Improve this question.

Gabriel Staples. Gabriel Staples Gabriel Staples 13 13 silver badges 12 12 bronze badges. This will prove helpful: unix. Does this answer your question? ThomasDickey, despite your 60, reputation, that seems a pretty far stretch to downvote this question and try to mark it as a duplicate of that completely unrelated question which happens to also use the -eu hashbang options. So no, it does not answer my question.

I've added it as a "related" link to the bottom of my question now. ThomasDickey, how -e and -u work with regard to traps or anything else is completely unrelated to how they and other single-character options can be given on the command line. Show 2 more comments. Active Oldest Votes. Improve this answer. I found them on the manpage on Debian. Looks like one would have to know to check the set pages after reading the start of the man bash page, but man set doesn't show these options either, so you'd have to know to then check help set , which does show the -e and -u options, and their brief descriptions.

That logical flow process to find this information is quite obscure. GabrielStaples, well, yeah. The shell builtins don't have man pages of their own. FreeBSD Commands. Full Man Repository. Advanced Search. Contact Us. Forum Rules. Mark Forums Read. Thread Tools.

View Public Profile for xerox. Find all posts by xerox. View Public Profile for Scott. Find all posts by Scott.