So, for example, if you renamed "file.txt" to just "textfile" then open textfile would still open it in the default text-file editing application, as long as file textfile still thought that "textfile" was actually a text file. You can use the "file" command to reveal what the operating system thinks the file type is: file file.txt. By default, this will be /Applications/TextEdit.app however, it's possible for this setting to get overridden:įinally, any file that's of the "text" type will get opened by the application bound to the text type if you just say open file.txt. The -t option means "open the file with the default application for editing text files, as determined via LaunchServices". The -e option means "open the file argument with the TextEdit application": The -a option means "open the file argument with the named application": It's also not set up to be inherited by child shells (which is totally a thing for environment variables) so Bash reverts to the unhelpful default of just showing you which version of it is running.Here are some possible answers, all using the 'open' command-line utility. When you just run a child instance of Bash, /etc/bashrc isn't re-executed, so this variable isn't set. that's somewhat OSX-specific on most other systems, you'd prefer ~/.bashrc for that. This is set up for you in /etc/bashrc, but you can set a new value, ideally in ~/.bash_profile. When run from the Terminal app, that variable is set to prompt you with the machine name, directory and user. Try typing echo $PS1 in both the parent and child instance of Bash. What happens when you type bash into Bash (through Terminal)? It starts the program Bash - that is, another copy of itself inside itself.ĮTA: The prompt that Bash gives you before you're typing each command is usefully customizable, and controlled (using a special format) by the variable PS1. If you're feeling cheeky, you could even make it use a program that isn't a shell at all - not too useful, but it demonstrates how Terminal cares only about passing characters in and out, not about what the shell does with them. In its settings, you could choose a different shell from Bash. When you open the Terminal app, it automatically opens a shell to connect you to. ls -l), or to interpret them on its own (e.g. When you press some keys, it figures out whether to send them on to the shell as characters (e.g. For ease of access later, you can keep Terminal in your Dock. Once you’re in the Utilities folder you will see the application Terminal.Open the Terminal application and you’re ready to go. First open the Applications folder, then open the Utilities folder. the characters "command not found" and figures out how to display them to you - with what font, where on the screen, in what colour, whether there should be a scrollbar. To access Bash in MacOS, you can use an application called Terminal. Now, Terminal is a program that provides a graphical interface between the shell and the user. When it runs another program, by default it connects the inputs and outputs of that program to the same streams. The shell mostly doesn't care - it reads the characters, interprets them as commands telling it to run other programs, and writes back characters such as "command not found". Properly speaking, a GUI you use to start programs by double-clicking on icons is also a shell, but in practice by "shell" people mostly mean command-line ones.Īll modern command-line shells take their input and send their output as abstract streams of characters, and the other ends of those streams can be connected to a keyboard, a printer, a file, another program. The command-line part means you control it by typing commands one line at a time. Bash is one of the popular command-line shells, programs whose chief job is to start other programs (in addition to some auxiliary functions).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |