General programming languages and shells have different priorities. Specifically a shell programming language should be designed to make launching external appl

General programming languages and shells have different priorities. Specifically a shell programming language should be designed to make launching external applications and processing their output the top priority. The language also needs to focus on easy of interactive input, so much so that the repl and the language or somewhat coupled. You wouldn't have a command in a general purpose programming language to execute the same line of code as you did 5 lines ago, that would be worse than goto. However, in a shell, such a thing sounds nice. The shell also needs to make it convenient to deal with some OS level objects, such as files. This is where glob syntax comes in handy. This all cascades to make a language that looks much different than you would want to write a full application in. One of the primary reasons is because of how shells need to handle strings. It is much more convenient to not type out quotes around string literals and it is nice to have syntax to reference environment variables, files, previous commands, etc. This leads to extremely complex quoting and expansion rules in most shells. It is not intuitive, but once learned it makes for a great interactive experience (compared with traditional languages).