I'm looking for a way to run terminal commands from in Swift (macOS). I came accross this post, but I can't seem to get any of the solutions to work. I am trying to shut down my mac from my app as you can do from terminal (osascript -e 'tell app "loginwindow" to «event aevtrsdn»'), but whenever I do it, I get error: Couldn't posix_spawn: error 13.
I am using this code:
func shell(launchPath: String, arguments: [String] = []) -> (String? , Int32) {
let task = Process()
task.launchPath = launchPath
task.arguments = arguments
let pipe = Pipe()
task.standardOutput = pipe
task.standardError = pipe
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8)
task.waitUntilExit()
return (output, task.terminationStatus)
}
and I call it from this:
let z = shell(launchPath: "/usr/bin/osascript", arguments: ["-e", "\'tell app \"loginwindow\" to «event aevtrsdn»\'"])
Any help?
Your code is correct, but you must not enclose the second argument
in single-quotes:
let z = shell(launchPath: "/usr/bin/osascript", arguments: ["-e", "tell app \"loginwindow\" to «event aevtrsdn»"])
That is only necessary when executing a program from the shell.
Process passes the given arguments directly to the spawned executable,
without interpretation by a shell.
Related
I want to execute the following shell command from my macOS app:
/Users/macuser/Desktop/videos/ffmpeg -i /Users/macuser/Desktop/videos/vid1.mov -vf fps=1/1 /Users/macuser/Desktop/videos/images/out%0d4.jpg
The method I'm using to do this is:
func shell(_ launchPath: String, _ arguments: [String]) -> String?
{
let task = Process()
task.launchPath = launchPath
task.arguments = arguments
let pipe = Pipe()
task.standardOutput = pipe
task.standardError = pipe
task.launch()
let data = pipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: .utf8) ?? ""
task.waitUntilExit()
return output
}
I am passing the arguments to the method like this:
let command = ffmpegLocation
let arguments = [
"-i",
videoLocation,
"-vf",
"fps=1/1",
"\(outputLocation)/out%0d4.jpg"
]
resultsField.stringValue = shell(command,arguments)!
What I get is "launch path is not accessible". I have verified the command does work in Terminal. Do I need to use a different approach?
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
}
I created a swift function which runs command in bash which is :
func getConnectedDevices(lblOut: NSTextView)
{
let pipe = Pipe()
let process = Process()
process.launchPath = "/bin/bash"
process.arguments = ["--login", "-c", "mobiledevice get_device_prop DeviceName"]
process.standardOutput = pipe
let fileHandle = pipe.fileHandleForReading
process.launch()
lblOut.string += "\n" + String(data: fileHandle.readDataToEndOfFile(), encoding: .utf8)!
}// Gets all connected iOS Devices
This function works if I just use mobiledevice in command but when I pass proper command to obtain list it gives me error that command not found. I am not very experienced in swift.
The issue resolved by itself. I don't really know how as I didn't change anything at all.
Wanting to get a details of all installed applications by executing system_profiler SPApplicationsDataType
The snippet given below works just fine in playground, however gives me code signing internal problem: unexpected error from xpc when I try executing it from an application.
func shell(_ command: String) -> String {
let task = Process()
task.launchPath = "/bin/bash"
task.arguments = ["-c", command]
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
}
print(shell("system_profiler SPApplicationsDataType"))
P.S Apologies if this is a dumb question, I'm fairly new to swift and xcode technologies :)
The following function executes a process in Swift 3 on macOS. But if I run the same code in Ubuntu I get the error that Process is an unresolved identifier.
How do I run a process / task in Swift 3 for Ubuntu and get its output?
import Foundation
// runs a Shell command with arguments and returns the output or ""
class func shell(_ 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? = String(data: data,
encoding: String.Encoding.utf8)
task.waitUntilExit()
if let output = output {
if !output.isEmpty {
// remove whitespaces and newline from start and end
return output.trimmingCharacters(in: .whitespacesAndNewlines)
}
}
return ""
}
I cannot test it myself currently, but according to the source code
https://github.com/apple/swift-corelibs-foundation/blob/master/Foundation/NSTask.swift,
the corresponding class is (still) called Task on Linux, not Process
as on Apple platforms.