此代码用于获取进程的标准输出
NSTask * task;
NSPipe * pipe;
NSFileHandle * fileHandle;
task = [ [ NSTask alloc ] init ];
pipe = [ NSPipe pipe ];
fileHandle = [ pipe fileHandleForReading ];
[ task setLaunchPath: @"/usr/bin/lspci" ];
[ task setArguments:[NSArray arrayWithObject:@"-nn"]];
[ task setStandardOutput: pipe ];
[ task setStandardError: pipe ];
[ task launch ];
[ task waitUntilExit];
[ task release];
NSData *outputData = [[pipe fileHandleForReading] readDataToEndOfFile];
NSString *outputString = [[[NSString alloc] initWithData:outputData encoding:NSUTF8StringEncoding] autorelease];
由于某些系统上不存在/usr/bin/lspci
,因此出现此 fatal error
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'launch path not accessible'
如何事先检查lspci
是否存在,如果不存在则向用户显示错误消息?
最佳答案
检查文件是否存在且可执行:
BOOL exists = [[NSFileManager defaultManager] isExecutableFileAtPath:[task launchPath]];
丢失文件并不是您遇到异常的唯一原因。您应该始终使用 @try
-@catch
block 。
关于cocoa - NSTask:进程的启动路径是否存在,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7050018/