objective-c - NSTask 运行 pdftk 命令

Question

我正在为学校项目使用 cocoa 应用程序为 pdftk 制作一个界面，但由于某种原因它无法工作，它会抛出此错误

Error: Unable to find file.
Error: Failed to open PDF file: 
   articulo.pdf
Done.  Input errors, so no output created.

我的文件下载的当前目录 这是我当前的代码

- (IBAction)getMetadata:(id)sender {

    task = [[NSTask alloc] init];

    NSString *arg = [NSString stringWithFormat:@"%@", fileNamePDF];
    [task setCurrentDirectoryPath: directory];
    task = [NSTask launchedTaskWithLaunchPath:@"/usr/local/bin/pdftk" arguments:@[arg, @"dump_data"]];

    task = nil;
}

Answer 1

“launchedTaskWithLaunchPath”创建新对象(您可以在调试器中检查)。这是适合您的方法:

- (IBAction)getMetadata:(id)sender {
    task = [[NSTask alloc] init];
    NSPipe  *outputPipe = [NSPipe pipe];
    [task setStandardOutput:outputPipe];
    NSFileHandle *outputFileHandle = [outputPipe fileHandleForReading];
    NSString *arg = [NSString stringWithFormat:@"%@", fileNamePDF];
    [task setCurrentDirectoryPath: directory];
    [task setLaunchPath:@"/usr/local/bin/pdftk"];
    [task setArguments:@[arg, @"dump_data"]];
    [task launch];
    [self.task waitUntilExit];
    //read output
    NSData *outputData = [outputFileHandle readDataToEndOfFile];
}