swift main run / build from command line - swift

Question

I will build an CLI Tool in Swift. I have created the project with this command swift package init --type executable
When I build my project and parse the read-aliases parameter in Xcode and click the "Play" Button everything worked fine.
I defined the read-aliases parameter
Then I receive the right output it is the following, the aliases from my .zsh file
These are your Aliases
zshconfig="mate ~/.zshrc"
ohmyzsh="mate ~/.oh-my-zsh"
python="/usr/local/bin/python3.7"
python2="/usr/bin/python2"
Program ended with exit code: 0
But when I run the following command swift run inside my project in the command line
Then I receive
Which seems to work so far these are the messages from my tool.
An when I parse the same parameter like this
$ swift run read-aliases
I get this error
error: no executable product named 'read-aliases'
Here is my code
import Foundation
import ArgumentParser
struct Alias: ParsableCommand {
static let configuration = CommandConfiguration(
abstract: "Make Editing Your .zshrc Much Easier",
subcommands: [readAliases.self])
}
extension Alias {
struct readAliases: ParsableCommand {
static let configuration = CommandConfiguration(
abstract: "Reads All The Aliases In Your .zshrc File")
func run() {
print("These are your Aliases");
readFile(path: "/Users/alexanderhess/.zshrc")
}
func readFile(path: String) -> Int {
errno = 0
if freopen(path, "r", stdin) == nil {
perror(path)
return 1
}
while let line = readLine() {
if(line.starts(with: "# alias")){
print(line.dropFirst(8));
}
}
return 0
}
}
}
Alias.main();
My Package.swift
// swift-tools-version:5.3
// The swift-tools-version declares the minimum version of Swift required to build this package.
import PackageDescription
let package = Package(
name: "easy-aliaser",
dependencies: [
// Dependencies declare other packages that this package depends on.
// .package(url: /* package url */, from: "1.0.0"),
.package(url: "https://github.com/apple/swift-argument-parser", from: "0.2.0"),
],
targets: [
// Targets are the basic building blocks of a package. A target can define a module or a test suite.
// Targets can depend on other targets in this package, and on products in packages this package depends on.
.target(
name: "easy-aliaser",
dependencies: [
.product(name: "ArgumentParser", package: "swift-argument-parser")
]),
.testTarget(
name: "easy-aliaserTests",
dependencies: ["easy-aliaser"]),
]
)
Here is my github repository in case you would like to reproduce it.
So why I receive this Error in the Command Line but not in Xcode?
Thanks in advance.

Answer 1

the problem
the command command line specify sub-command but miss the executable product
$ swift run read-aliases
the solution
you must use the executable product before sub-command
swift run easy-aliaser read-aliases
steps to reproduce
[so-test]$ git clone https://github.com/CreaTorAleXander/easy-aliaser
Cloning into 'easy-aliaser'...
remote: Enumerating objects: 41, done.
remote: Counting objects: 100% (41/41), done.
remote: Compressing objects: 100% (32/32), done.
remote: Total 41 (delta 2), reused 38 (delta 1), pack-reused 0
Unpacking objects: 100% (41/41), done.
[so-test]$ cd easy-aliaser
#
# [easy-aliaser (main)]$ swift package generate-xcodeproj
# edited the wired filename in your code just to refer to an existing file
# run the project in XCode without problems
# back to the command line
#
[easy-aliaser (main)]$ swift run easy-aliaser read-aliases
Fetching https://github.com/apple/swift-argument-parser
Cloning https://github.com/apple/swift-argument-parser
Resolving https://github.com/apple/swift-argument-parser at 0.3.1
/Users/me/projects/so-test/easy-aliaser/Sources/easy-aliaser/main.swift:23:13: warning: result of call to 'readFile(path:)' is unused
readFile(path: "/Users/me/projects/so-test/65203567/myzshrc")
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[3/3] Linking easy-aliaser
These are your Aliases
who_listening='sudo lsof -nP -iTCP -sTCP:LISTEN'
du-docker="du -h ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/Docker.qcow2 && docker images"
du-openshift=" /Users/ronda/.docker/machine/machines/openshift/disk.vmdk && du -h ~/.docker/machine/machines/openshift/boot2docker.iso"