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如何将Swift字符串数组传递给带有char **参数的C函数

更新时间:2023-02-12 16:12:01

C函数

int initialize(int argc, char **argv);

映射为Swift,

func initialize(argc: Int32, argv: UnsafeMutablePointer<UnsafeMutablePointer<Int8>>) -> Int32

这是一个可能的解决方案:

This is a possible solution:

let args = ["-c", "1.2.3.4", "-p", "8000"]

// Create [UnsafeMutablePointer<Int8>]:
var cargs = args.map { strdup($0) }
// Call C function:
let result = initialize(Int32(args.count), &cargs)
// Free the duplicated strings:
for ptr in cargs { free(ptr) }

它使用在strdup($0)中的事实 Swift字符串$0会自动转换为C字符串, 如 UnsafePointer< UInt8>中的字符串值所述函数参数行为.

It uses the fact that in strdup($0) the Swift string $0 is automatically converted to a C string, as explained in String value to UnsafePointer<UInt8> function parameter behavior.