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flagon-io/hello

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Greets people from the command line. The sample repository for g1t.

hello/README.md

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1# hello
2
3Greets people from the command line.
4
5## Usage
6
7| Argument | Description |
8| -------- | ----------- |
9| `NAME` | Optional. The name to greet. Only the first argument is read. Defaults to the `USER` environment variable, then to `world`. |
10| `--shout` | Upper-cases the greeting. |
11| `--version` | Prints the crate version and exits. |
12| `--times N` | Prints the greeting `N` times. Defaults to 1. |
13
14```sh
15$ cargo run -- Ada
16Hello, Ada!
17```
18
19```sh
20$ cargo run -- --shout Ada
21HELLO, ADA!
22```
23
24```sh
25$ cargo run -- --times 2 Ada
26Hello, Ada!
27Hello, Ada!
28```
29
30```sh
31$ cargo run -- --version
320.1.0
33```
34
35With no name it greets whoever is signed in.
36
37## Output
38
39```sh
40$ cargo run -- Grace
41Hello, Grace!
42```
43
44## Develop
45
46This project uses the Rust 2021 edition.
47
48```sh
49cargo test
50```
51
52## Troubleshooting
53
54**`error: --times value must be a number, got "abc"`**
55
56`--times` needs a whole number of zero or more. If the value is anything else, such as `abc`, `-1` or `2.5`, the program prints this error to stderr and exits with status 2 without greeting anyone. Pass a plain number, for example `--times 3`. A `--times` with no value after it also fails, with `--times requires a value`.
57
58**The greeting says `Hello, world!` when I gave a name**
59
60An empty or whitespace-only name, such as `cargo run -- ""`, is treated as no name and the greeting uses `world`. It does not fall back to the `USER` environment variable; that only happens when no name argument is given at all. Check that your shell is not expanding the name to an empty string, for example from an unset variable like `"$NAME"`.
61
62## License
63
64This project is licensed under the MIT License.
65The full license text is available at https://opensource.org/license/mit.