Running shell commands in a swift script - swift

I am looking for a solutuion to run shell commands in a Swift script.
Here is my code:
func shellEnv(_ command: String) -> String {
let task = Process()
let pipe = Pipe()
task.standardOutput = pipe
task.standardError = pipe
task.arguments = ["-c", command]
task.launchPath = "/bin/zsh"
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8)!
return output
}
It works with built-in commands but it cannot deal with commands like "brew", "node" and other commands that were installed manually.
So how can I solve it?

You need to set the PATH environment variable for the task. This has been set in your terminal, which is why you are able to do brew and node and other cool things directly, without specifying their full path.
You can see what this is set to in your terminal by doing:
echo $PATH
and it will print something like (for me it has a bunch more things. This is only an excerpt):
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
If you copy and paste the entire output of echo $PATH, and put it into the environment property of task, then you will be able to use the same commands in your swift script as in your terminal.
task.environment = ["PATH": "<paste the output here>"]
As Alexander said in the comments, another way is to add the l option. Here is a MCVE:
#!/usr/bin/swift
// main.swift
import AppKit
func shellEnv(_ command: String) -> String {
let task = Process()
let pipe = Pipe()
task.standardOutput = pipe
task.standardError = pipe
task.arguments = ["-cl", command]
task.launchPath = "/bin/zsh"
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8)!
return output
}
print(shellEnv("brew list")) // assuming you have brew
To run, chmod +x main.swift then ./main.swift, and you will see all your homebrew packages listed.

Related

Open an http tunnel through a shell script programmatically in swift

I am trying to open either an Ngrok or Localtunnel as part of my swift program by using shell scripts. The problem is as neither shell script has a return, my main thread hangs. I could put it in a side thread that's permanently open, but I need to extract the url that gets outputted. Any ideas?
For reference this is how I am executing shell commands in swift.
func shell(_ command: String) -> String {
let task = Process()
let pipe = Pipe()
task.standardOutput = pipe
task.standardError = pipe
task.arguments = ["-c", command]
task.launchPath = "/bin/zsh"
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8)!
return output
}
followed by either
shell("ngrok http 3000")
or
shell("lt --port 9726")

How to run terminal command in swift from any directory?

I'm trying to creating a macOS application that that involves allowing the user to run terminal commands. I am able to run a command, but it runs from a directory inside my app, as far as I can tell. Running pwd returns /Users/<me>/Library/Containers/<My app's bundle identifier>/Data.
How can I chose what directory the command runs from?
I'm also looking for a way to get cd to work, but if I can chose what directory to run the terminal command from, I can handle cd manually.
Here is the code that I'm currently using to run terminal commands:
func shell(_ command: String) -> String {
let task = Process()
let pipe = Pipe()
task.standardOutput = pipe
task.arguments = ["-c", command]
task.launchPath = "/bin/zsh"
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8)!
return output
}
I'm using Xcode 12 on Big Sur.
Thanks!
There is a deprecated property currentDirectoryPath on Process.
On the assumption you won't want to use a deprecated property, after reading its documentation head over to the FileManager and look at is provisions for managing the current directory and their implications.
Or just use cd as you've considered – you are launching a shell (zsh) with a shell command line as an argument. A command line can contain multiple commands separated by semicolons so you can prepend a cd to your command value.
The latter approach avoids changing your current process' current directory.
HTH
To add to CRD's answer, if using the cd approach, you may also consider separating your commands using && to wait for the previous commands to complete successfully before proceeding to the next command that depends on it.
Try the command you wish to run in the terminal and see if it completes as expected
Eg: /bin/bash -c "cd /source/code/ && git pull && swift build"
If everything works as expected you can go ahead and use it in your swift code as so:
shell("cd /source/code/ && git pull && swift build")
On the topic of deprecations, you may want to replace
launchPath with executableURL
and
launch() with run()
Sample implementation with updated code:
#discardableResult
func shell(_ args: String...) -> Int32 {
let task = Foundation.Process()
task.executableURL = URL(fileURLWithPath: "/bin/bash")
task.arguments = ["-c"]
task.arguments = task.arguments! + args
//Set environment variables
var environment = ProcessInfo.processInfo.environment
environment["PATH"]="/usr/bin/swift"
//environment["CREDENTIALS"] = "/path/to/credentials"
task.environment = environment
let outputPipe = Pipe()
let errorPipe = Pipe()
task.standardOutput = outputPipe
task.standardError = errorPipe
do {
try task.run()
} catch {
// handle errors
print("Error: \(error.localizedDescription)")
}
task.waitUntilExit()
let outputData = outputPipe.fileHandleForReading.readDataToEndOfFile()
let errorData = errorPipe.fileHandleForReading.readDataToEndOfFile()
let output = String(decoding: outputData, as: UTF8.self)
let error = String(decoding: errorData, as: UTF8.self)
//Log or return output as desired
print(output)
print("Ran into error while running: \(error)")
return task.terminationStatus
}

How to show real time result while using terminal command in a swift script

I am using Xcode Project Renamer to rename my Xcode project, after that I used the code below to install pod file.
It's working good but the terminal showing result after pod installed. I want to show result while installing the pod.
#discardableResult
private func shell(_ command: String) -> String {
let task = Process()
task.launchPath = "/bin/bash"
task.arguments = ["-c", command]
let pipe = Pipe()
task.standardOutput = pipe
task.launch()
// pipe.fileHandleForReading.readDataToEndOfFile()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output: String = NSString(data: data, encoding: String.Encoding.utf8.rawValue)! as String
return output
}
let command = shell("pod install")
print(command)
Can someone help please.

Run shell command with pattern in Swift

I would like to run a shell command on many files that should match on a given filename regex. I found this code snippet that runs a shell command with arguments:
func shell(_ arguments: [String] = []) -> String {
let task = Process()
task.launchPath = "/usr/bin/env"
task.arguments = arguments
let pipe = Pipe()
task.standardOutput = pipe
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8) ?? "unknown"
return output
}
It runs great, but it does not resolve the parameters:
shell(["ls", "~/Desktop/*.txt"])
Does not resolve the * to all txt files, it tries to only work on a file called *.txt. Is there some option I need to set on Process?
Thanks in advance for your help!
I just found out the answer! The resolving of * and other patterns is done by the shell, Process only runs a given command. So the solution is to create a shell and run the command in there: (will do some clean up in the code, but this works)
shell(["bash", "-c", "ls ~/Desktop/*.txt"])

execute shell internal commands from swift

I am trying to execute shell commands from swift program. below is my program
func executeCommand(command: String, args: [String]) -> String {
let task = Process()
task.launchPath = command
task.arguments = args
let pipe = Pipe()
task.standardOutput = pipe
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output: String = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as! String
return output
}
When I use the path as /bin and try to execute ls command it works and prints the output. but when i try to run
executeCommand(command: "export DEVELOPER_DIR=\"/Applications/Xcode.app/Contents/Developer/\"", args: [""])
it is not working. I tried to find the location of export but terminal says it is inbuilt. How do i execute the export DEVELOPER_DIR from my swift program?