Process

Command Execution

import process

Running Commands

Function	Signature	Description
`runCommand`	`(cmd: String) r: CommandResult`	Execute shell command, capture output
`runProgram`	`(path: String) r: Int`	Execute program, return exit code
`runProgramRequest`	`(path: String, requestContent: String) r: Int`	Materialize private request content and execute an exact program path with one request-file argument, without a command shell
`execCommand`	`(cmd: String) r: CommandResult`	Execute a shell command and return status/output
`runCommandOutput`	`(cmd: String) r: String`	Execute and return stdout
`runCommandOrAbort`	`(cmd: String) r: Void`	Execute, abort on failure

CommandResult

Function	Description
`commandWasSuccessful(result)`	Check if command succeeded
`commandOutput(result)`	Get stdout output
`isSuccess(result)`	Check exit code == 0

Example

let result = runCommand("ls -la")
if commandWasSuccessful(result) {
    println(commandOutput(result))
}

let exitCode = runProgram("/usr/bin/gcc")

// Suitable for a structured request protocol: the helper path is not
// shell-expanded and the runtime creates and removes the private request file.
let helperStatus = runProgramRequest("/usr/lib/seen/seen-pkg", requestContent)

Process Management

Function	Signature	Description
`processFork()`	`r: Int`	Fork process (returns child PID in parent, 0 in child)
`waitPid(pid: Int, flags: Int)`	`r: Int`	Wait for child (0=blocking, 1=WNOHANG)
`processExit(code: Int)`	`Void`	Terminate process
`getPid()`	`r: Int`	Get current process ID

Note: Use processFork() instead of fork() to avoid shadowing POSIX fork().

Example

let pid = processFork()
if pid == 0 {
    // child process
    println("I'm the child")
    processExit(0)
} else {
    // parent process
    println("Child PID: {pid}")
    waitPid(pid, 0)
}

Environment Variables

import env

Function	Signature	Description
`get`	`(name: String) r: String`	Get env var (empty if missing)
`has`	`(name: String) r: Bool`	Check if env var exists
`set`	`(name: String, value: String) r: Bool`	Set env var
`removeEnv`	`(name: String) r: Bool`	Remove env var
`tryGet`	`(name: String) r: Option<String>`	Get env var as Option
`getOrDefault`	`(name: String, default: String) r: String`	Get with fallback

Example

let home = get("HOME")
println("Home: {home}")

if has("DEBUG") {
    println("Debug mode enabled")
}

set("MY_VAR", "hello")

Command-Line Arguments

let arguments = args()  // returns Array<String>
for arg in arguments {
    println(arg)
}

Shell Quoting

let safe = shellQuote("file with spaces.txt")
// Returns: 'file with spaces.txt'

Runtime Functions

Function	Description
`__ExecuteProgram(path)`	Execute program, return exit code
`__ExecuteProgramRequest(path, requestPath)`	Internal exact-argument primitive used by the structured request bridge
`__seen_fork()`	Fork process
`__seen_waitpid(pid, flags)`	Wait for child
`__seen_exit(code)`	Exit process
`__seen_getpid()`	Get PID
`__HasEnv(name)`	Check env var
`__GetEnv(name)`	Get env var
`__SetEnv(name, value)`	Set env var
`__RemoveEnv(name)`	Remove env var
`seen_runtime_init(argc, argv)`	Initialize runtime with args