clap/examples/pacman.md
Ed Page c90a4eabae fix(help): Make output more dense
In looking at other help output, I noticed that they use two spaces, in
place of clap's 4, and it doesn't suffer from legibility.  If it
doesn't make the output worse, let's go ahead and make it as dense so we
fit more content on the screen.

This is a part of #4132
2022-09-07 17:13:55 -05:00

79 lines
1.8 KiB
Markdown

[`pacman`](https://wiki.archlinux.org/index.php/pacman) defines subcommands via flags.
Here, `-S` is a short flag subcommand:
```console
$ pacman -S package
Installing package...
```
Here `--sync` is a long flag subcommand:
```console
$ pacman --sync package
Installing package...
```
Now the short flag subcommand (`-S`) with a long flag:
```console
$ pacman -S --search name
Searching for name...
```
And the various forms of short flags that work:
```console
$ pacman -S -s name
Searching for name...
$ pacman -Ss name
Searching for name...
```
*(users can "stack" short subcommands with short flags or with other short flag subcommands)*
In the help, this looks like:
```console
$ pacman -h
package manager utility
Usage: pacman[EXE] <COMMAND>
Commands:
query -Q --query Query the package database.
sync -S --sync Synchronize packages.
help Print this message or the help of the given subcommand(s)
Options:
-h, --help Print help information
-V, --version Print version information
$ pacman -S -h
Synchronize packages.
Usage: pacman[EXE] {sync|--sync|-S} [OPTIONS] [package]...
Arguments:
[package]... packages
Options:
-s, --search <search>... search remote repositories for matching strings
-i, --info view package information
-h, --help Print help information
```
And errors:
```console
$ pacman -S -s foo -i bar
? failed
error: The argument '--search <search>...' cannot be used with '--info'
Usage: pacman[EXE] {sync|--sync|-S} --search <search>... <package>...
For more information try --help
```
**NOTE:** Keep in mind that subcommands, flags, and long flags are *case sensitive*: `-Q` and `-q` are different flags/subcommands. For example, you can have both `-Q` subcommand and `-q` flag, and they will be properly disambiguated.
Let's make a quick program to illustrate.