OPS145 Lab 6 Newversion: Difference between revisions

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Special characters
= Special characters in the shell =
The terminal you've been using this whole time in the course is running an application called the shell. Specifically the bash shell.


This application (bash) has been written to interpret input from the user as some sort of a command; or as an argument; or as data. It's a very powerful application with many abilities, but almost all the user input comes from the keyboard.
There are only so many keys of the keyboard, and most of them are used to input human-readable characters. That means some of those characters will necessarily have multiple meanings. We will look at several such characters in this lab.
Here's most of the ASCII table (as much as I could fit on my screen). Note that most of the characters in this table are familiar to you, but some (especially the first 32) are probably brand new to you. You can see this table easily by running '''man ascii'''
= Special characters =
* wget/tar instead of firefox/archivemanager
* wget/tar instead of firefox/archivemanager
* .
* .
Line 10: Line 18:
** double quotes
** double quotes
*\
*\
*
* Back-quote does something else
* Revisit ls, cat, mkdir, rm, mv, cp with spaces and special characters
* Mismatched quotes
* Quotes to work with filenames with special characters, and other quotes

Revision as of 14:22, 24 February 2024

Special characters in the shell

The terminal you've been using this whole time in the course is running an application called the shell. Specifically the bash shell.

This application (bash) has been written to interpret input from the user as some sort of a command; or as an argument; or as data. It's a very powerful application with many abilities, but almost all the user input comes from the keyboard.

There are only so many keys of the keyboard, and most of them are used to input human-readable characters. That means some of those characters will necessarily have multiple meanings. We will look at several such characters in this lab.

Here's most of the ASCII table (as much as I could fit on my screen). Note that most of the characters in this table are familiar to you, but some (especially the first 32) are probably brand new to you. You can see this table easily by running man ascii

Special characters

  • wget/tar instead of firefox/archivemanager
  • .
  • ..
  • hidden files
  • * and ? wildcards
  • spaces in filenames
    • single quotes
    • double quotes
  • \
  • Back-quote does something else
  • Revisit ls, cat, mkdir, rm, mv, cp with spaces and special characters
  • Mismatched quotes
  • Quotes to work with filenames with special characters, and other quotes